SEPNZ Bulletin December 2019 by Sports & Exercise Physiotherapy NZ

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SEPNZ BULLETIN

ISSUE 12. DECEMBER 2019

Student Month: ACL reconstruction return to soccer—P16 Reducing the Risk of Patellofemoral Pain in Runners—P24

p32 SPRINZ: Rate of Force Development (RFD)

p35 Paediatric Resistance Training: Benefits, Concerns, and Program Design Considerations.

p38 UPCOMING SEPNZ COURSES

www.sepnz.org.nz

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SEPNZ EXECUTIVE COMMITTEE

Members Page

President - Blair Jarratt Vice-President - Timofei Dovbysh Secretary - Michael Borich Treasurer - Timofei Dovbysh Website - Hamish Ashton Sponsorship - Emma Lattey Committee Emma Clabburn Rebecca Longhurst Justin Lopes Emma Lattey

EDUCATION SUB-COMMITTEE Rebecca Longhurst (Chairperson) Emma Clabburn Justin Lopes Dr Grant Mawston

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CONTENTS SEPNZ MEMBERS PAGE See our page for committee members, links & member information

EDITORIAL: By SEPNZ President Blair Jarratt

CONFERENCE REPORT: ASICS Sports Medicine Australia Conference 2019

APP REVIEW: The Ottawa Rules App

GET TO KNOW YOUR EXEC: Emma Lattey

MEMBER BENEFITS: Discounts

ASICS ARTICLE: Dual Density Midsoles

FEATURE ARTICLE: ACL reconstruction return-to-soccer: Strength or Function? Budi Pranjoto

FEATURE ARTICLE: Reducing the Risk of Patellofemoral Pain in Runners. Thomas Wardhaugh

SPRINZ: Rate of Force Development (RFD) by Chris Juneau

CLINICAL REVIEW: Paediatric Resistance Training: Benefits, Concerns, and Program Design Considerations.

UPCOMING SEPNZ COURSES

RESEARCH PUBLICATIONS: BJSM December 2019 - Volume 53 - 23

CLASSIFIEDS

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EDITORIAL Welcome to our last bulletin for 2019.

We are keeping with tradition and making this edition our Student Special. Over the last number of weeks, our physiotherapy schools and employers have been preparing to welcome the newcomers to our profession. Congratulations to our 2019 graduates from AUT and Otago, we hope you have a great time and come back in 2020 refreshed and eager to start your career. Congratulations to our SEPNZ winners Kirsty Burrows from AUT and Sophie Maxtone from Otago. Kirsty was a member of the NZ U24 Women’s Underwater Hockey Team who won gold at the Age Group World Championships earlier this year. In addition to her sporting success, Kirsty achieved excellent grades throughout her physiotherapy degree. Well done Kirsty. Sophie completed a national survey on how physiotherapists are involved in the recognition, assessment and management of concussion in New Zealand. This topic continues to grow, and now more than ever it is important that as physiotherapists we are part of the team helping with recognition, treatment medically and with key funders. Great topic Sophie! As this issue is all about celebrating our students, we have two excellent articles submitted from Otago University. Budi Pranjoto has provided an excellent article as part of his post graduate Sports Physiotherapy paper exploring function and strength and the interplay between these variables post ACL reconstruction. This essay is a great read and will really get you thinking about strength and functional testing of clearance for sport and or the risk of ACL re-rupture. Thomas Warburgh completed a literature review for his Otago Sports Physiotherapy paper on patellofemoral pain in runners. This is a common problem seen clinically and Thomas's review explores potential risk factors and strategies targeted at reducing these - including a handy diagram.

recommend looking at our SEPNZ courses, particularly the Sideline Management course. A very hot course for 2020 we will be running a pilot Australian Physiotherapy Association level 1 course which is part of the pathway to an APA titled Sports Physiotherapist. We have dates for a Lower Limb in Sport and are looking to run our Injury Prevention and Sports Enhancement early in 2020, there are plenty of options. More information on these courses and dates can be found on page 40 of this bulletin. The Executive and Education Subcommittee would like to extend a huge thank you to our departing Education Subcommittee members Angela Cadogan and Chris Whatman. Their contribution and commitment to developing and providing fantastic Sports Physiotherapy education to our members over the years had been instrumental in our ability to deliver quality Sports Physiotherapy content to members. A special thank you must go to Angela who steered the ship for several years as chairperson. We will miss them both but wish them well with their future endeavors. So, when all is said and done - kick back and relax with some light reading from SEPNZ. From all of us here at the SEPNZ Executive - Merry Christmas, enjoy your holidays with family and friends, stay safe and we will see you back in 2020. Over and out.

Kind Regards Blair Jarratt SEPNZ President

This bulletin the executive focus is on Emma Lattey who is the newcomer to our team, and she has also provided the recent app reviews. This month Emma has picked out a clinical gem with an APP review on the Ottawa rules. This APP looks highly useful for all clinicians and is again free so head over to the app store and download this one straight away! Earlier this year we, as part of our SEPNZ – ASICS prize, sent Lee-Anne Taylor to the Sunshine Coast. Thanks Lee-Anne for the excellent round up of your time away at the ASICS Sports Medicine Australia conference on “Exercise is Medicine”. We are glad you found the content and destination an amazing experience. Members keep your eyes out for next year’s prize trip and applications for the ASICS grants which are part of our ongoing sponsorship arrangement. All you runners out there (or those of you that treat runners) should read Chris Bishops article on page 14 - courtesy of ASICS. There are some interesting points on dual density shoes and every runner likes a performance benefit with no extra effort. Talking about CPD – now is a great time to start to plan 2020’s courses. If you are involved in sport, we highly

Exec Member Justin Lopes with Kirsty Burrows

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CONFERENCE REPORT

ASICS Sports Medicine Australia Conference 2019, Sunshine Coast Thank you to ASICS for this awesome opportunity to

some of us we have a good fortune to be able to

attend

(SMA)

work with and monitor athletes in a performance

conference and to SEPNZ for supporting this! To

environment, so have very clear baselines and

Chris Horrocks from ASICS and his podiatry

norms for that person to work with.

comrades’, I’m glad you are all fit and healthy and

emphasis on the whole - collect information on well-

able to run long distances as your navigation skills

being – sleep, stress, mind-sets, nutrition and

need a bit of professional development!

hydration.

the

appreciated

Sports

your

Medicine

Australia

sponsorship,

I really

insights

and

unplanned tourist opportunities!

There was

In a clinical setting I would say the

challenge for us all is to collect more informative data on our clients than just their presenting condition to have

holistic

approach.

Within the sport

“Exercise is Medicine” is the focus of this review and

performance environment map a clear framework to

an overarching theme of the conference.

link to your outcomes goals, provide feedback in real

physiotherapists

working

with

exercise

As as

time and have honest conversations.

treatment modality we are well placed to be engaged

in multiple facets of exercise - Prehab (Injury and disease prevention); Rehabilitation and Performance. Start with the end goal in mind, what is the outcome that needs to be achieved?

Understand what

components are required to be evaluated, monitored and achieved.

What the requirements are for the

end outcome e.g. motor control, stability, mobility, strength and conditioning, psychological profiling and performance measures (Professor Phil Glasgow Head of Physiotherapy and Rehabilitation, Irish

Rugby Football Union).

While presented with a

performance perspective, good advice to heed with any client. Please note this presentation was given a few days after the All Blacks destroyed Ireland in the quarter finals, so well done Phil on a great presentation! Individualise always Carrying on from above know your individual – for

Image: Professor Phil Glasgow slide from keynote address Individualise except for kids’ device time – let’s understand the relationship between devices and CONTINUED ON NEXT PAGE >>

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CONFERENCE REPORT flourishing and get some guidelines on their use! The increase in mental health issues within children ages 10-14 in Canada is a concern and potentially a global trend. The Compass study is a prospective cohort project monitoring 90,000 secondary school children, with some interesting insights https:// uwaterloo.ca/compass-system/compass-systemprojects/compass-study (Professor Guy Faulkner, University of British Columbia). Loading monitoring and management Tissue healing and appropriate loading was a key focus in performance sport (Professor Phil Glasgow), understand the individuals’ previous tissue injuries, understand the tissue response both theoretically and individually, load appropriately, create tissue

Performance models are unstable and cannot be

adaptation, monitor and progress (avoid sudden

used practically for predictive purposes. Despite the

changes) accordingly.

fact that there is stronger evidence for using internal load, most practitioners in team sports prefer

Monitoring

systems

are

designed

provide

external load measures of training.

Athletes self-

information that can be used to inform coaches’

reported measures have stronger support and better

decision making and improve the training process,

feasibility than most objective athlete response

Professor Aaron Coutts, University of Technology

measure, however these are often not validated and

Sydney explored the current literature to provide the

we should be wary of them. In summary, training is

following insights.

“Fitness-fatigue model” and the

complex and practitioners need to embrace the

“Training process framework” provide a conceptual

uncertainty and use their clinical making skills for the

bases for athlete monitoring with the goals of

individual. In other words there is no magic bullet!

improving performance readiness and reducing injury risk through controlled training. There is little high

Physical activity is positive psychology in motion –

level evidence to show relationships between training

physical activity has the capacity to prevent mental

load and performance and/or injury in team sports

illness, foster positive emotions and teach individuals

and the currently training load models do not fit the

to buffer against the stresses of life and thrive in

proposed mechanistic models for injury (See image

adversity (Professor Guy Faulkner).

below from Kalkhoven, Watsfor & Impellizzeri, 2019

PERMA elements – positive emotion, engagement,

retrieved from https://osf.io/preprints/sportrxiv/vzxga/)

positive relationships, meaning and accomplishment

Using the

have been shown to increase happiness and wellbeing. “Butts in a boat” is a dragon boat rowing club for mean in the Vancouver area who have had a prostate

cancer

diagnosis

http://

CONTINUED ON NEXT PAGE >>

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CONFERENCE REPORT www.vancouverprostate.com/butts-in-a-boat/.

The

op, with the surgeon’s consent!

ability to monitor a particular group during an activity is beneficial within allied health alongside the

Research has also indicated that exposing children

obvious exercise profits. There’s the challenge NZ,

to different sports with multidirectional activities such

create meaningful programmes to target specific

as basketball, hockey and football creates a bone

groups for the delivery of exercise with the emphasis

tissue response that reduces stress fractures by

on the individual benefits.

50%, with better outcomes if the frequency has been prior to 10 years of age.

Earlier development of

Indeed Canada is well underway with it’s “Betters

cardiovascular fitness and muscular adaptation

campaign” based on following the trends in physical

allows for muscle memory and becomes easier for

activity of the nation have created a whole health

trained individuals to retrain. I have to say while my

campaign and resources for the nation https://

son has been involved in 10 different sports this year

www.participaction.com/en-ca. While I know we are

and getting him to and from everything has been a

into sport and exercise I couldn’t help but admire the

hassle, it’s great to have some evidence to support

breadth of their health campaign and emphasis on

the rationalisation of the petrol costs!

person monitoring. Several speakers referred to work within the Australian schools - “Burn to Learn” https:// app.education.nsw.gov.au/sport/File/3496 and “Iplay” Iplay.org.au are examples of programs to support

schools with the delivery of physical activity; Burn to Learn using high intensity interval training (HIIT) and Iplay skill development resources. Continued engagement in physical activity has not only physical benefits but also mental health. Prescribing Exercise like the Medicine it is was Professor Maria Fiatarone Singh, University of Sydney reviewing medication verses exercise effects Image:

Retrieved

from

https://

www.participaction.com/en-ca/everything-better/poop -better

young adults such as Cognitive dysfunction/brain atrophy, Depression, Hypertension, Hyperlipidaemia, Insomnia,

Start early! Early loading of tissue can lead to early return to play in elite sport (Professor Phil Glasgow), it was suggested for every day delayed for starting rehabilitation there was an increased 3.3 days to return to sport.

across the age ranges. Consider chronic diseases in

Within their environment shoulder

reconstructions surgeries begin loading 1 week post

Systematic

inflammation

and

Insulin

resistance/Glucose intolerance, with the exception of the last one there are no drugs available but research

indicates

exercise

effective

intervention. As we continue to age exercise therapy is still effective in comparison with drug therapy. With resistance training and cardiovascular training commonly

prescribed

but

current

research

CONTINUED ON NEXT PAGE >>

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CONFERENCE REPORT showing moderate intensity exercise delivered for 150 minutes per week can reduce mortality. Certainly frailty can be combated through resistance activities using our normal training parameters of 7080% of 1RM. So as we age we must consider the therapeutic benefits of resistance training for falls prevention etc. Exercise can be used as an intervention instead of

surgery.

Controversial work from Professor Ewa

Roos, Professor and Head of Research Unit, University

randomised provided

Southern

controlled

pain

relief,

Denmark

trials

where

68%

clinical

reviewing exercises relevant

improvements in function, postponement of TKJR surgery for 2 out of 3 subjects for 2 years with no serious adverse reactions. Of course prevention is the best medicine, given that 65% of OA joints (in Australia) are related to obesity

and joint injury.

Injury prevention protocols for

football and netball have good evidence of reducing injury risks.

Image: Sharon Kearney, Netball NZ

The movement of the strengthening

component of the 11+ to the end of training has improved compliance alongside the addition of the Copenhagen adduction to the strengthening regime. Great to see Sharon Kearney from Netball NZ had a poster presentation at the event about the reduction

Again thank you for the amazing opportunity to attend this conference, I feel incredibly inspired by what I heard and will be working towards change. â&#x20AC;&#x153;The first step towards getting somewhere is to decide that you are not going to stay where you areâ&#x20AC;? JP Morgan

in injury rates post NetballSmart re-launching.

While we are a group that is predominantly focused within Sport and Exercise, I would challenge us to all start thinking outside of our clinical environments and apply our knowledge into the community. implement

and

research

sport

and

Create, exercise

programmes and continue to push for a more active (and healthy) society.

Lee-Anne Taylor is a physiotherapist with a passion for injury prevention in youth. She works in education at the Eastern Institute of Technology in the Hawkes bay, lecturing in sport and exercise science and researching injury prevention programmes in Netball and Basketball.

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APP REVIEW

Back to the App... Your App Review The Ottawa Rules App Merry Christmas to all you awesome sports physios out there! This month’s app review is of the Ottawa Rules

App which is a simple an effective medical app that is worth a download this festive, summer sports season. The Ottawa Rules are a set of clinical decision rules developed at the Ottawa Hospital Research Institute and the University of Ottawa, Canada. The rules have been demonstrated to decrease unnecessary diagnostic imaging and emergency room wait times which enhances patient comfort and reduces health care costs. This medical app is part of a study and according to the authors will be expanded to include other Ottawa Rules soon.

What it is used for?

Seller: Size: Version: Category: Compatibility:

Ottawa Hospital Research Institute 61.8 MB 3.0.2 Medical Requires iOS 9.0 or later. Apple and Android

Languages: Age rating: Copyright: Price:

English 12+ Ó 2016 Dr Ian Stiell Free

This app was developed to make the Ottawa Rules more accessible.

Who would benefit from this App? Student and new grad physios, physios with sporting teams, and any health care providers who treat patients with musculoskeletal injuries. The Ottawa Rules included are:- C-Spine, Knee, Ankle, CT Head, Subarachnoid haemorrhage (SAH), and Transient Ischemic Attack (TIA) Rule. PRACTICAL APPLICATION I know that many of us have used the Ottawa ankle/knee and Canadian C-spine Rules for many years and likely feel competent with our assessment of whether an individual requires imaging. However, it doesn’t hurt to have a handy little app on our phones just in case we need to refresh our knowledge or double check clinical decision making in an acute musculoskeletal setting. The app is extremely easy to use by just ticking a box or boxes (or none) the app tells you whether diagnostic imaging is necessary. I would highly recommend this app for physio students or new grads, and for the rest of us it is a super quick and handy tool to have at our fingertips. CONTINUED ON NEXT PAGE >>

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APP REVIEW

Pros:

• • • • • •

Excellent and simple to use interface with quality illustrations and algorithms to apply rules at point of care High quality videos showing the author applying the rules by the bedside on simulated patients Links to all validation studies for the rules Available for Apple and Android App is free Should help decrease the overuse of imaging for musculoskeletal injuries by making Ottawa Rules approachable to every provider

Cons:

• • •

Medical app lacks some specifics on evidence based medicine unless you view all of the videos or read the linked articles Doesn’t contain all the Ottawa Rules at this point, eg. lacks concussion rule Some reviewers prefer other calculator apps which contain versions of these rules as well as other many other clinical decision tools and formulas.

OVERALL RATING = 4.8 / 5

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GET TO KNOW YOUR EXEC… EMMA LATTEY.

What role do you play and how long have you been on the exec? Since Feb 2019 - I’m the newest member and have recently been handed over the baton for sponsorship duties for SEPNZ, and I write the bulletin app reviews. Life outside of SEPNZ I’ve recently returned to NZ after a few years away so am enjoying my quality family time as a good daughter and aunty to 7 beautiful humans. Previous teams worked with / sporting background.

Many years spent on the side-lines of NZ rugby fields, with teams including Wellington College 1st XV and Hurricanes Rugby U18s, and have worked with elite level AFL and netball teams in Australia. Favourite tune on a road trip…….. The Killers or Muse. Favourite sporting physiotherapy moment Making friends for life with coaches, medical team members, strength and conditioning coaches, and players who then end up contacting you with injury concerns from all over the world. Also, working with rugby players at school level all the way through to All Black level. Work – where, what, role Currently working for CAPE Physio in the Hastings Health Centre, but making the move to Auckland in Feb 2020 to work for UniSports which is exciting. Favourite /best or worst destination as touring Physio and why eg temperature, medical facilities etc The Wellington Rugby Sevens back in the glory days at the cake tin – best medical team and awesome imaging facilities.

MEMBER BENEFITS

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There are many benefits to be obtained from being an SEPNZ member. For a full list of Members’ Benefits visit http://sportsphysiotherapy.org.nz/benefits/

In each bulletin we will be highlighting individual member benefits in order to help members best utilise all benefits available.

issuu Our newsletters are available as a flip book online on ISSUU http://issuu.com/sportsphysiotherapynz There are also heaps of other resources on the site and a number of them have been grouped for your benefit. Click the “Stacks” button to find copies of sports related magazines for free. These include: Football Medic, Journal of Physiotherapy and Sports Medicine, Sports Performance and Technology and more.

Podcasts

Podcasts are recorded interviews or talks that are made available for access anytime. A number of sports medicine related podcasts are available which have been linked to our website. http://sportsphysiotherapy.org.nz/members/resources/freepodcasts

Journals

Not studying at present and miss the library at physio school? There are a number of journals that are available online for free. This list is increasing as more companies are developing free access journals, but please let Hamish know if you are aware of ones not on the list. We currently have a list of sports medicine, orthopaedic related and sports science. http://sportsphysiotherapy.org.nz/members/resources/journal/

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ASICS ARTICLE

Dual Density Midsoles Dr. Chris Bishop PhD Is there a role for dual density midsoles in modern

range, despite evidence presented by Malisoux and co-

athletic shoes?

authors that some dual density designs are associated

Running is a popular activity. And despite a small popula-

with lower injury risk. So is there a role for dual density

tion that continue to support the barefoot and minimalist

midsoles in 2019? I want to delve into the best part of four

movement, most runners are wearing shoes. Each year,

years research to share our investigation findings and the

recreational runners purchase up to three pairs of running

two big lessons we learnt along the way.

shoes, with the purchases being in part motivated by the expectation of improved running performance. But how

Lesson 1: Not all dual density systems are the

do we identify the right shoe for an individual? Well de-

same.

spite the large number of running shoes sold each year,

I think its unfair to label dual density systems donâ&#x20AC;&#x2122;t work.

there are currently no criteria to help runners decide

Because the Brooks Adrenaline was a different design to

which is the best running shoe for them. This results in

the ASICS Kayano, which was then different to the NIKE

shoe selection based on subjective assessments of shoe

Structure Triax and New Balance 860. Some posts were

characteristics and anecdotally-based marketing literature

hard density. Some posts were different in geometric de-

and product information from shoe manufacturers, or vid-

sign. If we consider ASICS DUOMAX system, it is simply

eo gait analysis results from technical retail stores.

a thin (say 10mm thick) wall in the medial midsole in the midfoot that was never purported to act on the subtalar

Traditionally, running shoes have been categorised

joint, where as the former Adrenaline was a wall of stiffer

based on levels of support ranging from structured cush-

midsole material in the posterior heel of the shoe. Similar

ioning to motion control. Underpinning the concept of

concepts yet differing positions equals different purported

support is the presence of different midsole designs. Dual

function. Heck you could argue the Nimbus is a dual den-

density footwear (characterised by two differing density

sity system in the past with fluid ride midsole system actu-

layers of a midsole) has been a keepsake of athletic foot-

ally being composed of two differing midsole materials

wear design for the best part of 30 years. The long held

which will each respond in different ways.

belief was that dual density midsoles stopped the foot from pronating through loading response and midstance,

If we are going to make conclusive statements about

as well as providing medial stability to the shoe. Despite

something working/not working, you have to be comparing

this anecdotal categorisation of running shoes, evidence

apples with apples.

from the literature does not support the premise the foot-

wear can control motion [1]. However, runners continue

Lesson 2: The literature hasnâ&#x20AC;&#x2122;t actually properly in-

to purchase this shoe on the basis that it feels more com-

vestigated the effects of these designs on running

fortable and stable for them when they run.

biomechanics. When you look at the design of most studies investigating

There has no doubt been a lot of pressure with regards to

dual density footwear, the outcomes used are a result of

the effect of this type of footwear and whether it should

the instantaneous effects of the shoe, and it is therefore

still exist of recent times. Largely anecdotal and pseudo

unknown what the acquired effect of the shoe is overtime,

expert opinion without a huge amount of published evi-

whether that be after defined periods of running or accu-

dence to support such strong statements. There are cer-

mulative periods of wear.

tainly brands removing dual density systems from their CONTINUED ON NEXT PAGE >>

PAGE 15

ASICS ARTICLE This design error becomes really important in terms of clinical translation. Runners often don’t report issues straight away, but more so 5-10kms into a run. The question has to be asked what is happening at this point when someone starts to experience symptoms? Perhaps they are getting tired and the function of the body (not just foot and ankle) is changing. Not ignoring the role of age of shoes in performance, but fatigue has been shown to reduce performance. Research suggests that stride patterns deterio-

rate in the presence of fatigue ( or running near exhaustion)[2], increased rearfoot eversion magnitude and velocity [3-5], a decrease in step time / shorter stride length / increased cadence [6], reduced plantar loading [2, 6], reduced peak vertical GRF [7, 8] and reduced leg-spring behaviour [2, 7]. This is of interest as the role of footwear as a ‘protective’ mechanism to changes in postural demand (e.g. fatigue) rather than a ‘motion control’ system to change foot function has not been evaluated. Given our internal wear test data suggests that shoes with varying midsole densities are more stable, it is plausible to hypothesise that the effect of such shoes may not be one

of motion control, but of improved stability in the presence

shoe mass, it was between 2 and 7 grams. We then got people to run both fresh and in the presence of fatigue (with fatigue created in a protocol where participants were asked to run back-to-back 3km time trials as quick as they could). What we found was instantaneously, there was a physiological benefit (2%) running in the DuoMAX shoe regardless of foot posture, with the benefit increasing to 3% when running in the presence of fatigue. This also translated into a performance benefit, with the dual density shoe assisting in maintaining performance (i.e. faster time trial performance in the dual density shoe)

in the presence of fatigue. This was measured as a 6.8s improvement in 3km time trial performance, equating to an improvement of some 24 m. This is a clear and substantial benefit of the DUOMAX design feature. And something that should be considered in a lot of recreational runners…fatigue influences performance! So to sum up…is there a role for dual density systems in modern athletic shoes? Based on our data, the answer is YES. And that is why it is exciting to see DUOMAX continue in the latest evolution of GT 2000-8.

of changes to postural demand (e.g. exerted state or fa-

But we can’t say the results we found are applicable to all

tigue).

dual density systems. Different systems will work different-

This last point has driven me to search for answers on what the DUOMAX system in ASICS footwear actually does. It has been in Kayano for 26 years. It’s sat within most stability models in the range. And yet we didn’t (nor did the industry) have a really good understanding of what it actually did. So what did we do to investigate this?

I presented our work on this recently at the Footwear Biomechanics Congress in Kannaskis, Canada. For those interested, the abstract is published in Footwear Science from the meetings proceedings. But we built two versions

ly, and individuals will respond differently to each system. And yes I am sure there are other design concepts that may be able to achieve similar effects. Let me be clear that the results we found were specific to ASICS DUOMAX midsole system. The concept of shoe design is about providing a depth of choice for runners. Where we now need to head and more our attention towards is how best to identify runners in need of these type of features in their shoes. That’s another discussion all together… References—on request

of the Kayano 23 in the factory, with the only difference between the shoes being the presence (or lack of) DUOMAXTM design. For those interested in the difference in

CONTINUED ON NEXT PAGE >>

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FEATURE ARTICLES

ACL reconstruction return-to-soccer: Strength or Function? Budiman Pranjoto (Budi), BBiomedSc (FUHB), BPhty, PGDipPhty (OMT) Introduction Anterior cruciate ligament (ACL) injury is one of the more common and serious injuries sustained by football players, some even requiring surgical reconstruction (Bizzini, Hancock, & Impellizzeri, 2012). However, the rehab protocol for soccer players returning to sport after ACL reconstruction is not well defined (Bizzini, et al. 2012). A concern for athletes who have had an ACL reconstruction is the incidence of reinjury and surgical revision (Nagelli & Hewett, 2016). There are multiple aspects to return-to-sport after an ACL reconstruction, such as nutrition, general health, biomedical and psychological readiness. However, as physiotherapists, we generally “clear” an athlete to return-to-sport after they achieve good mobility (range of motion) with good strength and/or function relevant to their sport. For the purpose of this written assignment, we will primarily discuss rehabilitation goals and tests that are grounded around strength compared to function. This essay will discuss recent evidence around strength vs. function for return-to-sport for soccer players after an ACL reconstruction. I will discuss pros and cons for each of them and when strength or function is more

appropriate if one of them is superior to one another. For clarification, I define strength as a performance measure (e.g. peak torque) to produce an isolated movement (e.g. knee extension), while function is the ability to produce movement involving multiple joints in a functional pattern (e.g. hopping). When are strength or functional measures more appropriate? test.

Does strength affect function? While strength is defined as an isolated movement measure, it is important to consider that strength may result in better function as well. Schmitt, Paterno, and Hewett (2012) demonstrated this very well. Ninety

soccer players were involved in their study, 55 had undergone

ACL

reconstruction

and

were

uninjured. Maximum voluntary isometric contraction (MVIC) of quadriceps femoris was measured on both legs to give a quadriceps index for symmetry (involved/uninvolved × 100%). The 55 players with ACL reconstruction were then sub-grouped to those with high quadriceps index (≥90%), and low (<80%). The functional measurement outcome was a hop

The players that had ACL reconstruction and high quadriceps index performed similarly in the hop test compared to uninjured controls. However, the players that had ACL reconstruction but had low quadriceps

index (asymmetry), performed significantly worse in the hop test compared to uninjured controls. The result of this study brings evidence to what is intuitively understood that strength and functional outcome measures may not be two independent variables – but one can affect another. It is important that in this study, causality was not established between the two variables, correlation is found but strength does not necessarily lead to function and CONTINUED ON NEXT PAGE >>

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FEATURE ARTICLE function does not lead to strength.

strength and circumference compared to the control group. This study showed that NMES was an

A similar study by Clagg, Paterno, Hewett, and

effective treatment to improve strength gain.

Schmitt (2015) was completed with modified Star Excursion Balance Test (mSEBT) and isokinetic

Another study by Paillard, Noe, Bernard, Dupui, and

dynamometry. Sixty-six participants who have had a

Hazard (2008) also investigated the effects of NMES

unilateral ACL reconstruction and 47 uninjured

with a vertical jump test – a functional measure. The

participants (controls) were tested. The participants

study included 27 healthy trained students. They

with ACL reconstruction were tested at the time of

were divided into three groups: controls, NMES for

return to sport. mSEBT included the anterior,

strength

posterolateral

and

parameters). The participants performed vertical

quantify

jump tests at the beginning of the study, at one week

strength. The participants with ACL reconstruction

and at five weeks at the end of the study after

had significantly lower anterior reach distance in the

completing their NMES programme or control. The

mSEBT on the involved and uninvolved limbs

groups

compared to the uninjured participants (controls).

endurance significantly increased their vertical jump

Furthermore, they found an association between the

height in the test, showing NMES was effective in

lower mSEBT anterior reach distance and lower

improving a functional measure.

isokinetic

and

posteromedial

dynamometry

was

used

reaches to

and

that

NMES

received

for

endurance

NMES

for

(different

strength

extremity muscle strength measured in the isokinetic dynamometry. This demonstrates once again that

These two studies showed that NMES was an

strength and function are not two independent

effective treatment that improves both strength and

variables but may be associated with each other.

function. This is consistent with the first point of the discussion: strength and function may not be two

Can a treatment or rehabilitation protocols affect both? A study by Taradaj, et al. (2013) investigated the use of neuromuscular electrical stimulation (NMES) for soccer athletes post-ACL reconstruction. Eighty soccer

athletes

post-ACL

reconstruction

were

involved in this study, who were then divided into

NMES (n=40) and control (n=40) groups. Both the control and NMES group underwent the same treatment rehabilitation protocols, including functional and progressive resisted exercises. The NMES group had NMES applied three days a week for a month. Both the control and NMES groups increased quadriceps muscle strength measured by tensometry

independent variables, and physiotherapy may be able to improve both at the same time. In the scope of this essay, I will not delve into different treatments that would affect both or one but not the other – I will focus on strength vs. functional goals/tests. A point to note is that in Paillard, Noe, Bernard, Dupui, and Hazard’s 2008 study, they did not have soccer players or athletes as participants, and they were healthy participants. That may mean that their results may not be directly applicable to soccer players post-ACL reconstruction. However, these two studies still point to the finding that a single treatment may have effects on strength and on function.

and quadriceps circumference. However, the NMES group had increased significantly more in quadriceps CONTINUED ON NEXT PAGE >>

PAGE 18

FEATURE ARTICLE Good function and poor strength

not show a statistical difference in the YBT-LQ

It is generally accepted that if the soccer players are

scores (both independent and composite scores).

not ready to return to sport if they have poor strength

Similarly, the cleared and not cleared groups did not

and function –(Arundale, Silvers-Granelli, & Snyder-

show a statistical difference in the FMS composite

Mackler, 2018). The fact that strength and function

scores. This suggests similar results to Herrington, et

are not necessarily two independent variables as

al. (2018) that people post-ACL reconstruction can

demonstrated above are also convenient in making

“pass” their functional measures, but “fail” the

return-to-sport protocol and tests. However, what

strength measures.

happens when the function test does not reflect the

however, FMS is composed of seven separate tests

strength test?

and their composite score will not be as valid as the

A criticism for this

study

individual scores on the seven tests which can each Herrington,

Ghulam,

and

Comfort

(2018)

be a “pass” or “fail” on their own.

demonstrated this phenomenon exactly in their study. Fifteen full-time professional soccer players

This brings us to the question then: how do these

who have undergone ACL reconstruction were

people and athletes perform well functionally, but

involved in this study. Eccentric, concentric and

have poor strength? The answer may lie in the

isometric peak torque strength were measured and

original definition of strength. Strength was measured

compared to their distances in a single hop for

in an isolated single joint performance, while function

distance

–

usually involves multiple joints working together. This

normalised to their leg length. The injured and

may mean contribution from other joints and muscle

uninjured leg were compared for symmetry with the

groups may hide strength deficits that are present in

goal of ≥90% for both strength and hop distance.

isolation. Hence, functional tests are not sensitive

Herrington, Ghulam, and Comfort (2018) found that

enough to detect isolated strength deficits which was

more than 80% of the players did not achieve ≥90%

also described by Thomeé, et al. (2011) in their

symmetry for strength, while 67-73% achieved ≥90%

review – asking for more sensitive tests.

and

cross-over

hop

for

distance

symmetry for the hop tests. This showed that majority

participants

had

good

functional

outcomes, but poor strength measures.

Most

the

evidence

investigating

functional

measures usually also include one or two functional measures (e.g. single hop distance, mSEBT, cross-

Mayer, et al. (2015) found similar results with a

over hop distance), while this is easily reproducible

different set of measurements. Clinical impairments,

and consistent, real-life soccer players do not just

including

were

hop or reach on the spot. Soccer players perform

measured and 98 patients post-ACL reconstruction

wide and diverse functional movements with their

were group in either cleared or not cleared to return

movements (e.g. running, change in direction,

to sport by the orthopaedic surgeon performing the

kicking), which should be clinically checked before

clinical impairment measurements. A blinded tester

returning to sports. The other functional movements

then performs the Functional Movement Screen

may then show a strength deficit that was not

(FMS) and the Y Balance Test for Lower Quarter

detected from a hop or reach test alone.

isokinetic

quadriceps

strength,

(YBT-LQ) as the functional measures. The results showed that the cleared and not cleared groups did CONTINUED ON NEXT PAGE >>

PAGE 19

FEATURE ARTICLE Good strength and poor function?

Paterno, et al. (2010) showed the importance of

Surprisingly at the time of this writing, there are no

neuromuscular control to predict a second ACL

evidence and examples in the literature of any

injury. There may be cases where soccer players

athlete having good strength but poor function,

who have had an ACL reconstruction have good

especially soccer athletes post-ACL reconstruction.

strength

However, there is no evidence of their absence

neuromuscular control, unable to utilise separate

either. It would not be too surprising for anecdotal

isolated muscular strength together to perform a

evidence and clinical evidence of strong and healthy

functional movement. The equipment used by

individuals or athletes being unable to perform

Patreno, et al. (2010) would not be available in most

simple functional tasks such as single leg stance.

clinical settings, but the principle in testing function

Similarly, there would be healthy individuals who are

to detect neuromuscular control deficit which may

unable to perform functional tests such as the FMS

predict a second ACL injury is still applicable.

but

poor

function

due

poor

well. Which would give a clear example of good strength but poor function.

Conclusions: Strength and function It has been established that strength and function

There is a prospective study by Paterno, et al. (2010)

may not be separate independent variables to test

which investigated landing and postural stability

or achieve, but one may affect another. Some

function using a 3-D motion analysis and Biodex SD

treatments such as NMES may also result in

Stability System. A drop vertical jump manoeuvre

improved both strength and function, though this

and postural stability assessment was analysed on

may not be the case for all treatments and

56 athletes who have had an ACL reconstruction and

rehabilitation protocols. However, in the context of

followed for occurrence of a second ACL injury.

return-to-sport tests and criteria, these two are not

Valgus movement, asymmetry in internal knee

independent variables.

extensor moment and a deficit in single-leg postural stability of the involved limb were specific predictive

Despite strength and function being associated,

parameters. On top of that, hip rotation moment

should we test one, or both? It appears that

independently predicted second ACL injury (C =

functional tests are not sufficiently sensitive to

0.81) with high sensitivity (0.77) and specificity

detect isolated strength deficits, possibly because

(0.81).

altered

other joints and/or muscles can come in to

neuromuscular control of the hip and knee during the

compensate for the strength deficit. However, on a

functional tasks are predictors of a second ACL

similar note, neuromuscular control seems to be a

injury.

strong predictor of a second ACL injury in athletes

The study by Paterno, et al. (2010) demonstrated the

which cannot be ignored. There is an absence of

reason why clinicians perform functional tests in the

evidence showing that athletes can have good

first place: neuromuscular control. Neuromuscular

function but poor strength, hence appropriate

control is the ability to use the separate isolated parts

functional tests should still be performed to detect

(quadriceps and glute muscles) to perform together

neuromuscular control deficits. In conclusion, until

in a functional task. While there is no evidence of

evidence proves otherwise, strength and function

athletes having good strength but poor function or

should both be tested and soccer athletes who have

The

neuromuscular

authors

control

concluded

post-ACL

that

reconstruction, CONTINUED ON NEXT PAGE >>

PAGE 20

FEATURE ARTICLE had an ACL reconstruction need to be able to pass

jump tests at the beginning of the study, at one

both tests to return-to-soccer.

week and at five weeks at the end of the study after

and isokinetic dynamometry was used to quantify

completing their NMES programme or control. The

strength. The participants with ACL reconstruction

groups

had significantly lower anterior reach distance in the

endurance significantly increased their vertical jump

mSEBT on the involved and uninvolved limbs

height in the test, showing NMES was effective in

compared to the uninjured participants (controls).

improving a functional measure.

that received

NMES

for

strength

Furthermore, they found an association between the lower mSEBT anterior reach distance and lower

These two studies showed that NMES was an

extremity muscle strength measured in the isokinetic

effective treatment that improves both strength and

dynamometry. This demonstrates once again that

function. This is consistent with the first point of the

strength and function are not two independent

discussion: strength and function may not be two

variables but may be associated with each other.

independent variables, and physiotherapy may be

athletes

post-ACL

reconstruction

were

involved in this study, who were then divided into NMES (n=40) and control (n=40) groups. Both the control and NMES group underwent the same treatment rehabilitation protocols, including functional and progressive resisted exercises. The NMES group had NMES applied three days a week for a month. Both the control and NMES groups increased quadriceps muscle strength measured by tensometry and quadriceps circumference. However, the NMES

able to improve both at the same time. In the scope of this essay, I will not delve into different treatments that would affect both or one but not the other – I will focus on strength vs. functional goals/ tests. A point to note is that in Paillard, Noe, Bernard,

Dupui, and Hazard’s 2008 study, they did not have soccer players or athletes as participants, and they were healthy participants. That may mean that their results may not be directly applicable to soccer players post-ACL reconstruction. However, these two studies still point to the finding that a single treatment may have effects on strength and on function.

group had increased significantly more in quadriceps

Good function and poor strength

strength and circumference compared to the control

It is generally accepted that if the soccer players are

group. This study showed that NMES was an

not ready to return to sport if they have

effective treatment to improve strength gain.

strength and function –(Arundale, Silvers-Granelli, &

Another study by Paillard, Noe, Bernard, Dupui, and

Snyder-Mackler, 2018). The fact that strength and

Hazard (2008) also investigated the effects of NMES

function are not necessarily two independent

with a vertical jump test – a functional measure. The

variables

study included 27 healthy trained students. They

convenient in making return-to-sport protocol and

were divided into three groups: controls, NMES for

tests. However, what happens when the function

strength

test does not reflect the strength test?

and

NMES

for

endurance

(different

demonstrated

above

are

poor

also

parameters). The participants performed vertical CONTINUED ON NEXT PAGE >>

PAGE 21

FEATURE ARTICLE Herrington,

Ghulam,

and

Comfort

(2018)

be a “pass” or “fail” on their own.

demonstrated this phenomenon exactly in their study. Fifteen full-time professional soccer players

This brings us to the question then: how do these

who have undergone ACL reconstruction were

people and athletes perform well functionally, but

involved in this study. Eccentric, concentric and

have poor strength? The answer may lie in the

isometric peak torque strength were measured and

original

compared to their distances in a single hop for

measured in an isolated single joint performance,

distance

–

while function usually involves multiple joints

normalised to their leg length. The injured and

working together. This may mean contribution from

uninjured leg were compared for symmetry with the

other joints and muscle groups may hide strength

goal of ≥90% for both strength and hop distance.

deficits that are present in isolation. Hence,

Herrington, Ghulam, and Comfort (2018) found that

functional tests are not sensitive enough to detect

more than 80% of the players did not achieve ≥90%

isolated strength deficits which was also described

symmetry for strength, while 67-73% achieved ≥90%

by Thomeé, et al. (2011) in their review – asking for

symmetry for the hop tests. This showed that

more sensitive tests.

majority

and

cross-over

participants

hop

had

for

good

distance

definition

strength.

Strength

was

functional

outcomes, but poor strength measures.

Most of the evidence investigating functional measures usually also include one or two functional

Mayer, et al. (2015) found similar results with a

measures (e.g. single hop distance, mSEBT, cross-

different set of measurements. Clinical impairments,

over hop distance), while this is easily reproducible

including

were

and consistent, real-life soccer players do not just

measured and 98 patients post-ACL reconstruction

hop or reach on the spot. Soccer players perform

were group in either cleared or not cleared to return

wide and diverse functional movements with their

to sport by the orthopaedic surgeon performing the

movements (e.g. running, change in direction,

clinical impairment measurements. A blinded tester

kicking), which should be clinically checked before

then performs the Functional Movement Screen

returning to sports. The other functional movements

(FMS) and the Y Balance Test for Lower Quarter

may then show a strength deficit that was not

(YBT-LQ) as the functional measures. The results

detected from a hop or reach test alone.

isokinetic

quadriceps

strength,

showed that the cleared and not cleared groups did not show a statistical difference in the YBT-LQ scores (both independent and composite scores). Similarly, the cleared and not cleared groups did not show a statistical difference in the FMS composite scores. This suggests similar results to Herrington, et al. (2018) that people post-ACL reconstruction can “pass” their functional measures, but “fail” the strength measures. A criticism for this study however, FMS is composed of seven separate tests and their composite score will not be as valid as the individual scores on the seven tests which can each

Good strength and poor function? Surprisingly at the time of this writing, there are no

evidence and examples in the literature of any athlete having good strength but poor function, especially soccer athletes post-ACL reconstruction. However, there is no evidence of their absence either. It would not be too surprising for anecdotal evidence and clinical evidence of strong and healthy individuals or athletes being unable to perform simple functional tasks such as single leg stance. Similarly, there would be healthy individuals CONTINUED ON NEXT PAGE >>

PAGE 22

FEATURE ARTICLE who are unable to perform functional tests such as

control deficit which may predict a second ACL

the FMS well. Which would give a clear example of

injury is still applicable.

good strength but poor function. Conclusions: Strength and function There is a prospective study by Paterno, et al. (2010)

It has been established that strength and function

which investigated landing and postural stability

may not be separate independent variables to test

function using a 3-D motion analysis and Biodex SD

or achieve, but one may affect another. Some

Stability System. A drop vertical jump manoeuvre

treatments such as NMES may also result in

and postural stability assessment was analysed on

improved both strength and function, though this

56 athletes who have had an ACL reconstruction and

may not be the case for all treatments and

followed for occurrence of a second ACL injury.

rehabilitation protocols. However, in the context of

Valgus movement, asymmetry in internal knee

return-to-sport tests and criteria, these two are not

extensor moment and a deficit in single-leg postural

independent variables.

stability of the involved limb were specific predictive parameters. On top of that, hip rotation moment

Despite strength and function being associated,

independently predicted second ACL injury (C =

should we test one, or both? It appears that

0.81) with high sensitivity (0.77) and specificity

functional tests are not sufficiently sensitive to

(0.81).

altered

detect isolated strength deficits, possibly because

neuromuscular control of the hip and knee during the

other joints and/or muscles can come in to

functional tasks are predictors of a second ACL

compensate for the strength deficit. However, on a

injury.

similar note, neuromuscular control seems to be a

The

authors

concluded

that

strong predictor of a second ACL injury in athletes The study by Paterno, et al. (2010) demonstrated the

which cannot be ignored. There is an absence of

reason why clinicians perform functional tests in the

evidence showing that athletes can have good

first place: neuromuscular control. Neuromuscular

function but poor strength, hence appropriate

control is the ability to use the separate isolated parts

functional tests should still be performed to detect

(quadriceps and glute muscles) to perform together

neuromuscular control deficits. In conclusion, until

in a functional task. While there is no evidence of

evidence proves otherwise, strength and function

athletes having good strength but poor function or

should both be tested and soccer athletes who have

neuromuscular

had an ACL reconstruction need to be able to pass

control

post-ACL

reconstruction,

Paterno, et al. (2010) showed the importance of

both tests to return-to-soccer.

neuromuscular control to predict a second ACL injury. There may be cases where soccer players who have had an ACL reconstruction have good strength but poor function due to poor neuromuscular control, unable to utilise separate isolated muscular strength together to perform a functional movement. The equipment used by Patreno, et al. (2010) would not be available in most clinical settings, but the principle in testing function to detect neuromuscular CONTINUED ON NEXT PAGE >>

PAGE 23

FEATURE ARTICLE Budiman Pranjoto (Budi) is a physiotherapist based in a private practice in Dunedin. He completed this essay towards the requirements of the post-graduate Sports Physiotherapy paper at the School of Physiotherapy, University of Otago, as part of a PGDipPhty in Orthopaedic Manipulative Therapy. He works with various sports but a particular area of interest is in racket-based sports, especially badminton, squash and tennis. References Arundale, A. J. H., Silvers-Granelli, H. J., & Snyder-Mackler, L. (2018). Career Length and Injury Incidence After Anterior Cruciate Ligament Reconstruction in Major League Soccer Players. Orthopaedic Journal of Sports Medicine, 6(1), 232596711775082. doi: 10.1177/2325967117750825 Bizzini, M., Hancock, D., & Impellizzeri, F. (2012). Suggestions From the Field for Return to Sports Participation Following Anterior Cruciate Ligament Reconstruction: Soccer. Journal of Orthopaedic & Sports Physical Therapy, 42(4), 304–312. doi: 10.2519/jospt.2012.4005 Clagg, S., Paterno, M. V., Hewett, T. E., & Schmitt, L. C. (2015). Performance on the Modified Star Excursion Balance Test at the Time of Return to Sport Following Anterior Cruciate Ligament Reconstruction. Journal of Orthopaedic & Sports Physical Therapy, 45(6), 444–452. doi: 10.2519/ jospt.2015.5040

Herrington, L., Ghulam, H., & Comfort, P. (2018). Quadriceps Strength and Functional Performance After Anterior Cruciate Ligament Reconstruction in Professional Soccer players at Time of Return to Sport. Journal of Strength and Conditioning Research, 1. doi: 10.1519/jsc.0000000000002749 Mayer, S. W., Queen, R. M., Taylor, D., Moorman, C. T., Toth, A. P., Garrett, W. E., & Butler, R. J. (2015). Functional Testing Differences in Anterior Cruciate Ligament Reconstruction Patients Released Versus Not Released to Return to Sport. The American Journal of Sports Medicine, 43(7), 1648–1655. doi: 10.1177/0363546515578249 Nagelli, C. V., & Hewett, T. E. (2016). Should Return to Sport be Delayed Until 2 Years After Anterior Cruciate Ligament Reconstruction? Biological and Functional Considerations. Sports Medicine, 47(2), 221–232. doi: 10.1007/s40279-016-0584-z

Paillard, T., Noe, F., Bernard, N., Dupui, P., & Hazard, C. (2008). Effects of Two Types of Neuromuscular Electrical Stimulation Training on Vertical Jump Performance. Journal of Strength and Conditioning Research, 22(4), 1273–1278. doi: 10.1519/jsc.0b013e3181739e9c Paterno, M. V., Schmitt, L. C., Ford, K. R., Rauh, M. J., Myer, G. D., Huang, B., & Hewett, T. E. (2010). Biomechanical Measures during Landing and Postural Stability Predict Second Anterior Cruciate Ligament Injury after Anterior Cruciate Ligament Reconstruction and Return to Sport. The American Journal of Sports Medicine, 38(10), 1968–1978. doi: 10.1177/0363546510376053 Schmitt, L. C., Paterno, M. V., & Hewett, T. E. (2012). The Impact of Quadriceps Femoris Strength Asymmetry on Functional Performance at Return to Sport Following Anterior Cruciate Ligament Reconstruction. Journal of Orthopaedic & Sports Physical Therapy, 42(9), 750–759. doi: 10.2519/

PAGE 24

FEATURE ARTICLES

Reducing the Risk of Patellofemoral Pain in Runners Thomas Wardhaugh, BPhty (Hons) Introduction In New Zealand, running is one of the most common sporting activities participated in by young people and adults (Sport NZ, 2017). Running is frequently associated with lower limb injuries (Taunton et al., 2002), with the knee being the most commonly injured joint. Patellofemoral pain (PFP) is the most common specific injury in running, accounting for 17% of all injuries (Francis, Whatman, Sheerin, Hume, & Johnson, 2019). A recent systematic review by Smith et al. (2018) found an annual incidence of PFP in the general population of 22.7%, and 28.9% in adolescents. In active populations, reported incidences of PFP range from 3-15% (Neal, Barton, Gallie, Oâ&#x20AC;&#x2122;Halloran, & Morrissey, 2016). As injury is likely the most common reason for novice runners to discontinue running (Fokkema et al., 2019), identification of risk factors for PFP and how these may be addressed, is important. This review of literature will identify a number of potential risk factors for PFP and review strategies targeted at reducing these.

What is Patellofemoral Pain?

Demographic and Anthropometric Factors:

PFP is characterised by diffuse pain of the anterior

Taunton et al. (2002) found a higher incidence of

knee, either retropatellar or peripatellar in nature

PFP in women compared to men. This has since

(Neal et al., 2019). It is most commonly aggravated

been disputed in two high quality review articles

by loaded knee flexion, such as squatting, ascending

finding no statistically significant association with PFP

stairs or descending stairs. Numerous structures can

and sex, age, or body mass index (BMI) (Neal et al.,

contribute

2016; Neal et al., 2019).

nociception

PFP,

including;

subchondral bone, infrapatellar fat pad, retinaculum

Muscular Changes:

and ligamentous structures, however the exact cause

Changes in the strength and activation of muscles of

is not known (Powers, Witvrouw, Davis, & Crossley,

the knee and hip have been long thought to be

2017). A widely cited paper by Dye (2005) introduced

associated

a pathophysiological model of PFP, focusing on a

(EMG) studies focussed on function of the vastus

disruption of tissue homeostasis in the patellofemoral

medialis oblique (VMO) compared with that of vastus

joint (PFJ) caused by factors such as inflammation.

lateralis (VL) in subjects with PFP. Multiple studies

The contribution of central pain mechanisms and

have found associations between PFP and delayed

psychosocial

contraction and decreased amplitude of VMO versus

factors must

also

considered

with

PFP.

Earlier

electromyography

(Powers et al., 2017).

VL (Cesarelli, Bifulco, & Bracale, 2000; Owings &

Risk Factors for PFP

Grabiner, 2002). However, a 2008 systematic review

A number of potential risk factors for PFP have been

found

hypothesised and researched, however there is

dysfunction and PFP based on the heterogeneity of

conflicting evidence for many of these factors.

study

clear

design,

association significant

between

normal

VMO-VL

inter-subject

CONTINUED ON NEXT PAGE >>

PAGE 25

FEATURE ARTICLE variability and the potential for bias in many studies

Dingenen,

2019).

(Chester et al., 2008).

differences

have

This said, generalised

Numerous been

biomechanical

studied

multiple

quadriceps weakness may be a risk factor (Neal et

populations, with the heterogeneity of variables

al., 2019).

studied, and study designs, contributing to the

More recent literature has focused on the association

limited conclusive evidence available.

of proximal muscle strength with PFP. Interestingly,

Magnitude of peak hip adduction moment is

results have been conflicting when comparing cross-

associated with increased PFJ stress (John D

sectional studies to prospective study designs. A

Willson & Davis, 2008), therefore it is reasonable to

cross-sectional study by Cowan, Crossley, and

suggest that hip adduction may be associated with

Bennell (2009) assessed the EMG activity of gluteus

PFP and subsequently, a number of studies have

medius (GM), VMO and VL as well as hip abduction

investigated this. In a prospective study of 400

and trunk side flexor strength in participants with and

female runners, those who developed PFP during

without PFP. Their findings showed a delay in GM

the two year study period were found to exhibit

and VMO activation as well as reduced trunk side

significantly greater hip adduction angle during

flexion strength in participants with a history of PFP.

running (Brian Noehren, Hamill, & Davis, 2013).

These findings are supported by baseline data

Whereas, in a cohort of collegiate cross country

measured by Ferber, Kendall, and Farr (2011) in

runners, increased hip adduction moment was not

their study investigating the effects of a hip abductor

found to increase risk of RRI, including PFP

strengthening

PFP.

(Dudley, Pamukoff, Lynn, Kersey, & Noffal, 2017).

Contrastingly, data from prospective studies has

Inconsistencies between studies may be due to the

found hip strength to decrease from baseline levels

small sample size in this paper (n=31) and relatively

in subjects who developed PFP during the follow-up

short follow up period (14 weeks). Peak rear-foot

period (Finnoff et al., 2011; Thijs, Pattyn, Van

eversion was originally thought to be a risk factor

Tiggelen,

Hip

for PFP, however this more recent literature does

abduction strength was even found to be greater in

not support this (Neal et al., 2016). Biomechanical

young basketballers who developed PFP (Herbst et

abnormalities appear in many individuals with PFP,

al., 2015). These findings suggest that weakness

however, these may occur secondary to PFP and

may occur secondary to PFP, rather than being

do not necessarily worsen with increasingly difficult

causal as was previously thought. Pooled data from

physical tasks (Willson & Davis, 2008).

systematic reviews supports this suggestion (Neal et

Sagittal plane biomechanics related to landing

al., 2019; Rathleff, Rathleff, Crossley, & Barton,

strategies during running have been shown to effect

2014).

PFJ loading, which may lead to PFP. Runners who

protocol

Rombaut,

for

runners

Witvrouw,

with

2011).

fore-foot strike (FFS) were shown to have reduced Biomechanical

and

Spatiotemporal

PFJ loading compared with those who rear-foot

Characteristics of Running:

strike (RFS) (Kulmala, Avela, Pasanen, & Parkkari,

Despite the belief that biomechanical factors play a

2013).

strong role in affecting risk of running-related injury

The spatiotemporal characteristics of running are

(RRI), limited evidence exists to support these claims

also important to consider. These include factors

(Ceyssens,

such as step length and cadence (step rate). A 10%

Vanelderen,

Barton,

Malliaras,

CONTINUED ON NEXT PAGE >>

PAGE 26

FEATURE ARTICLE increase in step length results in a 31% increase in

but not specified) in boys but not girls (Tenforde et

PFJ stress per step, equating to a 14% increase in

al., 2011). The effect of rapid increase in training on

load per mile. Moreover, 10% decrease accounts for

increased RRI risk was supported by prospective

a 22% decrease in loading per step, 7.5% decrease

data over a 1-year follow up period (Nielsen et al.,

per mile (Willson, Sharpee, Meardon, & Kernozek,

2014). Among a cohort of 874 healthy, novice

2014).

A 2014 systematic review analysed the

runners, those who increased their running load by

available literature regarding changes in step length

greater than 30% in a given week were at increased

during running and concluded that a shorter step

risk of distance related running injury, including PFP.

length results in reduced ground reaction force and

A popular method of maintaining safe progression of

subsequently, reduced absorption of force at the hip,

running training is the ‘10% rule’, where the

knee and ankle (Schubert, Kempf, & Heiderscheit,

maximum increase in training volume each week is

2014). Despite these reductions in ground reaction

10%. Buist et al. (2007) carried out a randomised

force

between

controlled trial (RCT) where novice runners preparing

increased cadence and PFP is yet to be shown in the

for a 4-mile (6.7 km) event were randomised into a

literature (Luedke, Heiderscheit, Williams, & Rauh,

‘standard training group’ who carried out an 8 week

2016).

training programme, or a ‘graded training group’ who

Training Load

performed a 13 week programme to reach the same

It is evident that there are a wide range of risk factors

point. Between groups, there was found to be no

for PFP in runners that may combine in individuals

differences in the incidence of RRI (PFP not

causing pain to arise, however these risk factors

specified). While this paper had a large sample size

rarely result in PFP in inactive individuals (Smith et

and was methodologically sound, the selected

al., 2018). It is often thought that a key component of

parameters of the ‘standard training group’ were far

PFP is simply an overload of tissues in the knee.

from the extremes often seen clinically. Perhaps, a

This may occur as a result of beginning running as a

more excessive running protocol for the control group

novice, or significantly increasing training loads.

may have revealed a protective effect of the ‘10%

There is strong evidence that excessive and rapid

rule’, in line with aforementioned prospective studies.

increases in training load can increase the overall

Reducing Injury Risk

risk of injury in sport (Gabbett, 2016). This is

A number of RCTs investigating general PFP injury

characterised by an increase in the acute:chronic

prevention interventions have been performed with

workload ratio, whereby the total summation of

mixed results. Many of these studies have selected

training time and intensity ‘this week’ is significantly

populations of military recruits, as the control of

more than the average of the past three weeks. Sixty

potentially confounding variables is made easier in

percent of all running injuries can be attributed to

this context. Conflicting results were found between

training errors of ‘too much, too soon’ (Hreljac, 2005).

two large RCTs investigating the efficacy of a general

The idea of ‘too soon’ combined with ‘too much’

lower limb strengthening and stretching programme

appears to be an important relationship. The

on AKP in military recruits. Brushøj et al. (2008)

evidence

proved

randomised participants into an intervention group of

inconclusive in a mixed population of 748 high school

lower limb strengthening and stretching three times

runners

was

per week, while the control group performed upper-

associated with increased risk of RRI (including PFP,

limb strengthening exercises. At 12-week follow up,

and

PFJ stress,

‘too

where

much’

higher

a correlation

isolation

weekly

mileage

CONTINUED ON NEXT PAGE >>

PAGE 27

FEATURE ARTICLE there was found to be no significant difference in the

Davis, 2012), respectively.

incidence of overuse knee injury between groups.

Considering spatiotemporal factors, gait retraining

Contrary to these findings, Coppack, Etherington,

interventions focussed on the sagittal plane have

and Wills (2011) reported a 75% reduction in the risk

also proven effective at increasing cadence, reducing

of AKP in their intervention group. In this study,

step

participants in the intervention group performed a

transitioning towards FFS (Lenhart, Thelen, Wille,

lower limb strength and stretching programme seven

Chumanov, & Heiderscheit, 2014; Roper et al.,

times per week for 14 weeks. It is possible that the

2016). All three of these factors have been shown to

improved outcomes of this group compared with

reduce PFJ stress during running. In a population of

those studied by Brushøj et al. (2008) are a result of

healthy

the higher frequency of exercise, longer duration of

investigated the change in forces on the knee when

the intervention period, as well as an increased

step rate was increased to 110% of preferred step

emphasis on unilateral strengthening exercises.

rate, finding a decrease in PFJ stress of 14%.

Specific

strengthening

Another interesting factor to consider, is the role of

programme targeting hip and core strength showed

footwear on joint forces. Minimalist footwear has

significant improvements in pain and functional ability

been shown to reduce PFJ stress during running, at

in a cohort of female runners already exhibiting

preferred cadence, by 15%, and when combined with

symptoms of PFP (Earl & Hoch, 2011).

a 10% increase in step rate, joint forces were

With regard to interventions aimed at reducing injury

reduced by 29% (Bonacci et al., 2018).

risk factors of PFP other than strength, few studies

As has been previously discussed, poorly managed

have been performed in pain free populations. While

training loads have the potential to contribute to

a gap in the published literature remains, to guide

running injuries regardless of whether the individual

clinical decision making, clinicians must make

exhibits any of the risk factors evaluated above.

sensible extrapolations from interventional studies

Training plans should be carefully planned and

involving participants with PFP.

individualised, with particular attention paid to the

Regarding

runners,

the

8-week

biomechanical

length

adult

and

improving

runners,

landing

Lenhart

strategies,

al.

(2014)

characteristics of

athlete’s training history. While the ‘10% rule’

running, evidence exists to support a link between

provides a useful guide, there is evidence to suggest

increased hip adduction and PFP (Noehren et al.,

novice runners may tolerate higher than 10%

2013). Two strategies exist to address this. Firstly,

increases, at least for a short period of time,

proximal muscle strengthening has been shown to

therefore a strict adherence to the 10% rule may

reduce hip adduction moments during running (Earl

delay progression to full capacity. Contrastingly, for

& Hoch, 2011), secondly, there is limited evidence

athletes with a high chronic training load, consecutive

supporting gait retraining as an effective intervention

10% weekly increases in training load may be

for runners with PFP. Two studies investigated the

excessive, and risk increased injury rates (Gabbett,

efficacy of a two week (four sessions per week) gait

2018).

retraining intervention focussing on frontal plane mechanics,

both

showing

reduced

peak

hip

Potential risk factors for PFP in runners and

adduction and pain levels following intervention,

interventions to address these identified in this

which was sustained at one month (Noehren, Scholz,

review of literature, are summarised in Figure 1,

& Davis, 2011) and three months (Willy, Scholz, &

below. CONTINUED ON NEXT PAGE >>

PAGE 28

FEATURE ARTICLE

RISK FACTORS

INTERVENTION

Hip weakness

Strengthening program

Quadriceps weakness

Gait retraining – frontal plane

↑ Peak hip adduction moment during running

Gait retraining – sagittal plane

↓ Cadence / ↑ Step length

Minimalist footwear

Excessive increase in training load

Training load monitoring – “10% rule” as a guideline

Conclusion Over 100 factors have been investigated as potential risk factors for PFP, making it a confusing area for clinicians to gain a clear understanding of the

literature and where emphasis for intervention should lie (Crossley, van Middelkoop, Barton, & Culvenor, 2019). It is important to consider that across a range of studies showing potential risk factors for PFP, very rarely did 100% of subjects exhibit a particular variable. Careful assessment of training history, strength and objective running evaluation will reveal potential contributing factors unique to the individual and

allow the

implementation

interventions

targeting these factors.

Thomas is a physiotherapist working in Dunedin. He works with athletes across a wide range of sports and levels of participation. Thomas has a strong interest in knee injuries, stemming from years of managing his own knee pain. He completed this literature review as part of requirements of the post-graduate Sports Physiotherapy paper at the School of Physiotherapy, University of Otago. CONTINUED ON NEXT PAGE >>

PAGE 29

FEATURE ARTICLE References

Bonacci, J., Hall, M., Fox, A., Saunders, N., Shipsides, T., & Vicenzino, B. (2018). The influence of cadence and shoes on patellofemoral joint kinetics in runners with patellofemoral pain. Journal of Science and Medicine in Sport, 21(6), 574-578. Brushøj, C., Larsen, K., Albrecht-Beste, E., Nielsen, M. B., Løye, F., & Hölmich, P. (2008). Prevention of overuse injuries by a concurrent exercise program in subjects exposed to an increase in training load: A randomized controlled trial of 1020 army recruits. American Journal of Sports Medicine, 36(4), 663670. doi:10.1177/0363546508315469 Buist, I., Bredeweg, S. W., van Mechelen, W., Lemmink, K. A. P. M., Pepping, G.-J., & Diercks, R. L. (2007). No Effect of a Graded Training Program on the Number of Running-Related Injuries in Novice Runners: A Randomized Controlled Trial. The American Journal of Sports Medicine, 36(1), 33-39. doi:10.1177/0363546507307505 Cesarelli, M., Bifulco, P., & Bracale, M. (2000). Study of the control strategy of the quadriceps muscles in anterior knee pain. IEEE Transactions on Rehabilitation Engineering, 8(3), 330-341. Ceyssens, L., Vanelderen, R., Barton, C., Malliaras, P., & Dingenen, B. (2019). Biomechanical risk factors associated with running-related injuries: a systematic review. Sports Medicine, 1-21. Chester, R., Smith, T. O., Sweeting, D., Dixon, J., Wood, S., & Song, F. (2008). The relative timing of VMO and VL in the aetiology of anterior knee pain: a systematic review and meta-analysis. BMC Musculoskeletal Disorders, 9(1), 64. Coppack, R. J., Etherington, J., & Wills, A. K. (2011). The effects of exercise for the prevention of overuse an-

terior knee pain: a randomized controlled trial. The American Journal of Sports Medicine, 39(5), 940948. Cowan, S. M., Crossley, K. M., & Bennell, K. L. (2009). Altered hip and trunk muscle function in individuals with patellofemoral pain. British Journal of Sports Medicine, 43(8), 584-588. Crossley, K. M., van Middelkoop, M., Barton, C. J., & Culvenor, A. G. (2019). Rethinking patellofemoral pain: Prevention, management and long-term consequences. Best Practice & Research Clinical Rheumatology. Dudley, R. I., Pamukoff, D. N., Lynn, S. K., Kersey, R. D., & Noffal, G. J. (2017). A prospective comparison of lower extremity kinematics and kinetics between injured and non-injured collegiate cross country runners. Human Movement Science, 52, 197-202. Dye, S. F. (2005). The pathophysiology of patellofemoral pain: a tissue homeostasis perspective. Clinical Orthopaedics and Related Research®, 436, 100-110. Earl, J. E., & Hoch, A. Z. (2011). A proximal strengthening program improves pain, function, and biomechanics in women with patellofemoral pain syndrome. American Journal of Sports Medicine, 39(1), 154163. doi:10.1177/0363546510379967 Ferber, R., Kendall, K. D., & Farr, L. (2011). Changes in knee biomechanics after a hip-abductor strengthening protocol for runners with patellofemoral pain syndrome. Journal of Athletic Training, 46(2), 142149. Finnoff, J. T., Hall, M. M., Kyle, K., Krause, D. A., Lai, J., & Smith, J. (2011). Hip strength and knee pain in high school runners: a prospective study. PM&R, 3(9), 792-801. CONTINUED ON NEXT PAGE >>

PAGE 30

FEATURE ARTICLE Fokkema, T., Hartgens, F., Kluitenberg, B., Verhagen, E., Backx, F. J., van der Worp, H., . . . van Middelkoop, M. (2019). Reasons and predictors of discontinuation of running after a running program for novice runners. Journal of Science and Medicine in Sport, 22(1), 106-111. Francis, P., Whatman, C., Sheerin, K., Hume, P., & Johnson, M. I. (2019). The proportion of lower limb running injuries by gender, anatomical location and specific pathology: A systematic review. Journal of Sports Science and Medicine, 18(1), 21-31. Gabbett, T. J. (2016). The training—injury prevention paradox: should athletes be training smarter and harder? British Journal of Sports Medicine, 50(5), 273-280. Gabbett, T. J. (2018). Debunking the myths about training load, injury and performance: empirical evidence, hot topics and recommendations for practitioners. British Journal of Sports Medicine, bjsports-2018099784. Herbst, K. A., Barber Foss, K. D., Fader, L., Hewett, T. E., Witvrouw, E., Stanfield, D., & Myer, G. D. (2015). Hip strength is greater in athletes who subsequently develop patellofemoral pain. The American Journal of Sports Medicine, 43(11), 2747-2752. Hreljac, A. (2005). Etiology, prevention, and early intervention of overuse injuries in runners: a biomechanical perspective. Physical Medicine and Rehabilitation Clinics, 16(3), 651-667. Kulmala, J. P., Avela, J., Pasanen, K., & Parkkari, J. (2013). Forefoot strikers exhibit lower running-induced knee loading than rearfoot strikers. Medicine and Science in Sports and Exercise, 45(12), 2306-2313. doi:10.1249/MSS.0b013e31829efcf7 Lenhart, R. L., Thelen, D. G., Wille, C. M., Chumanov, E. S., & Heiderscheit, B. C. (2014). Increasing running

step rate reduces patellofemoral joint forces. Medicine and Science in Sports and Exercise, 46(3), 557 -564. doi:10.1249/MSS.0b013e3182a78c3a Luedke, L. E., Heiderscheit, B. C., Williams, D. S. B., & Rauh, M. J. (2016). Influence of Step Rate on Shin Injury and Anterior Knee Pain in High School Runners. Medicine and Science in Sports and Exercise, 48(7), 1244-1250. doi:10.1249/MSS.0000000000000890 Neal, B. S., Barton, C. J., Gallie, R., O’Halloran, P., & Morrissey, D. (2016). Runners with patellofemoral pain have altered biomechanics which targeted interventions can modify: A systematic review and metaanalysis. Gait and Posture, 45, 69-82. Neal, B. S., Lack, S. D., Lankhorst, N. E., Raye, A., Morrissey, D., & van Middelkoop, M. (2019). Risk factors for patellofemoral pain: a systematic review and meta-analysis. British Journal of Sports Medicine, 53 (5), 270-281. Nielsen, R. O., Parner, E. T., Nohr, E. A., Sørensen, H., Lind, M., & Rasmussen, S. (2014). Excessive progression in weekly running distance and risk of running-related injuries: An association which varies according to type of injury. Journal of Orthopaedic and Sports Physical Therapy, 44(10), 739-747. doi:10.2519/jospt.2014.5164 Noehren, B., Hamill, J., & Davis, I. (2013). Prospective evidence for a hip etiology in patellofemoral pain. Medicine and Science in Sports and Exercise, 45(6), 1120-1124.

CONTINUED ON NEXT PAGE >>

PAGE 31

FEATURE ARTICLE Noehren, B., Scholz, J., & Davis, I. (2011). The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome. British Journal of Sports Medicine, 45(9), 691696. Owings, T. M., & Grabiner, M. D. (2002). Motor control of the vastus medialis oblique and vastus lateralis muscles is disrupted during eccentric contractions in subjects with patellofemoral pain. The American Journal of Sports Medicine, 30(4), 483-487. Powers, C. M., Witvrouw, E., Davis, I. S., & Crossley, K. M. (2017). Evidence-based framework for a pathomechanical model of patellofemoral pain: 2017 patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester, UK: part 3. British Journal of Sports Medicine, 51(24), 1713-1723. Rathleff, M., Rathleff, C., Crossley, K., & Barton, C. (2014). Is hip strength a risk factor for patellofemoral pain? A systematic review and meta-analysis. British Journal of Sports Medicine, 48(14), 1088-1088. Roper, J. L., Harding, E. M., Doerfler, D., Dexter, J. G., Kravitz, L., Dufek, J. S., & Mermier, C. M. (2016). The effects of gait retraining in runners with patellofemoral pain: A randomized trial. Clinical Biomechanics, 35, 14-22. doi:10.1016/j.clinbiomech.2016.03.010 Schubert, A. G., Kempf, J., & Heiderscheit, B. C. (2014). Influence of stride frequency and length on running mechanics: a systematic review. Sports Health, 6(3), 210-217. Smith, B. E., Selfe, J., Thacker, D., Hendrick, P., Bateman, M., Moffatt, F., . . . Logan, P. (2018). Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis. PloS One, 13(1), e0190892.

Sport NZ. (2017). Active NZ, The New Zealand participation survey 2017.

Retrieved from https://

sportnz.org.nz/assets/Uploads/Main-Report.pdf Taunton, J. E., Ryan, M. B., Clement, D. B., McKenzie, D. C., Lloyd-Smith, D. R., & Zumbo, B. D. (2002). A retrospective case-control analysis of 2002 running injuries. British Journal of Sports Medicine, 36(2), 95-101. doi:10.1136/bjsm.36.2.95 Tenforde, A. S., Sayres, L. C., McCurdy, M. L., Collado, H., Sainani, K. L., & Fredericson, M. (2011). Overuse Injuries in High School Runners: Lifetime Prevalence and Prevention Strategies. PM & R, 3(2), 125131. doi:10.1016/j.pmrj.2010.09.009 Thijs, Y., Pattyn, E., Van Tiggelen, D., Rombaut, L., & Witvrouw, E. (2011). Is hip muscle weakness a predisposing factor for patellofemoral pain in female novice runners? A prospective study. The American Journal of Sports Medicine, 39(9), 1877-1882. Willson, J. D., & Davis, I. S. (2008). Lower extremity mechanics of females with and without patellofemoral pain across activities with progressively greater task demands. Clinical Biomechanics, 23(2), 203-211. Willson, J. D., Sharpee, R., Meardon, S. A., & Kernozek, T. W. (2014). Effects of step length on patellofemoral joint stress in female runners with and without patellofemoral pain. Clinical Biomechanics, 29(3), 243247. doi:https://doi.org/10.1016/j.clinbiomech.2013.12.016 Willy, R. W., Scholz, J. P., & Davis, I. S. (2012). Mirror gait retraining for the treatment of patellofemoral pain in female runners. Clinical Biomechanics, 27(10), 1045-1051.

PAGE 32

SPRINZ

Rate of Force Development (RFD) and why physiotherapists should know about it. Chris Juneau, Physiotherapist PT, DPT, SCS, CSCS, Board-Certified Clinical Specialist in Sports Physical Therapy (SCS) Certified Strength and Conditioning Specialist (CSCS)

Dry Needling Certified & USA Weightlifting Coach Sports Performance Research Institute NZ, Auckland University of Technology. There is no question that objective data,

Let me explain a bit more about why this is

repeated testing, and functional assessments

potentially

are taking medicine by storm. The concept of

strength.

valuable

than

maximal

profiling individualsâ&#x20AC;&#x2122; capacity, both at a tissue and compound task level, have become common

If you consider an individual walking down a

processes in justifying progression through a

sidewalk and stumbling over a bump in the

rehabilitation program, to reintegration into activity

pavement, ask yourself what is more important

after injury, or in assessing risk factors in screening

avenues. The most commonly utilized testing

preventing a fall:

recovering

the

tripped

limb

and

mediums in the Physiotherapy world typically involve either peak force, or maximal strength,

1 - the ability to produce a maximal hip flexion force

(think in terms of a hand held dynamometer or

manual muscle test), or multi-joint functional tasks

2 - the ability to produce a hip flexion contraction

(single leg hop testing after anterior cruciate

quickly.

reconstruction or the timed up and go assessment in a fall-risk population). While these tests are

It should get your mind spinning a bit, specifically

certainly valuable, there is an emerging interest in

considering the fact that this person would need at

the concept of force and time, specifically the ability

least enough strength to pull their leg forward, but

to produce force quickly, which seems to better

ultimately, that value is certainly not a maximal

represent the comprehensive capacity of an

effort for most individuals, which brings us to RFD.

individual and better predict performance.

It should make a bit of sense to consider that moving quickly, recovering their leg via a rapid hip

This category of force-time characteristics is often

flexor contraction, will provide a better chance of

called rate of force development (RFD), which

preventing the fall by moving their leg quickly under

simply describes the force produced for a given

them.

period of time. That is the simple concept of RFD. This is valuable CONTINUED ON NEXT PAGE >>

PAGE 33

SPRINZ information when describing risk, or readiness, after

working with AUT to investigate easier and more

injury or in a performance environment, as

practical avenues for collection of this data. The

increases in RFD are also associated with

goal is to provide a cost effective, reliable, testing

improvements in performance in numerous

device that can help provide more information

activities such as sprint speed and weightlifting capacity, along with tasks of daily living, such as

If you would like to read a bit

increases in walking speed or sit to stand activities.

more about RFD here is a really great resource:

Below is a list of how RFD impacts activity: Slawinski J, Bonnefoy A, Leveˆque J, et al.

Maffiuletti

Kinematic and kinetic comparisons of elite and well-

Blazevich A. Rate of force develop-

trained sprinters during sprint start. J Strength Cond Res. 2010;24(4): 896–905.

Per

Aagaard

ment: physiological and methodological considerations. Eur J Appl

Stone M, Sands W, Carlock J, et al. The importance of isometric maximum strength and peak rate-of-force development in sprint cycling. J Strength Cond Res. 2004;18(4): 878–884.

strength testing: evaluation of tests of explosive force production. Eur J Appl Physiol. 2004 91:147– 154

the performance of specific tissues, movements, and tasks. My research question revolves around the use of a load cell, often referred to as a strain gauge, which

Clark D, Manini T, Fielding R, et al. Neuromuscular determinants of maximum walking speed in wellfunctioning older adults. Exp Gerontol. 2013; 48:358–363.

Now, I know what you are thinking, this sounds and most certainly will cost a large

investment, which is not very appealing, and I would certainly sympathize with that. Our current model involves using expensive machines, such as force plates and isokinetic dynamometers, and these

about the capacity of your clients, in an attempt to improve our profiling, and more objectively quantify

Mirkov D, Nedeljkovic A, Milanovic S, et al. Muscle

fancy

Physiol. 2016; 116:1091–1116.

tools

are

fantastic

for

research

and

academics, but not for clinical settings. Well, good news! Part of my time here in New Zealand is

is the big brother to a hand held dynamometer, but significantly more practical and portable than a force plate or isokinetic device, and how it can be used in clinical settings to acquire RFD. First things first, my aim is to assess the reliability

of the tool and the set-up, which is important to make sure we have consistency in the data capture, and eventually compare performance of a healthy group to an unhealthy group. My principle measure is knee extension (quadriceps function) and my unhealthy population will be a cohort of individuals with anterior knee pain. Essentially, I want to look at the RFD differences in both individuals with and without anterior knee pain, but CONTINUED ON NEXT PAGE >>

PAGE 34

SPRINZ also look at differences between the painful and nonpainful limbs in that same cohort. This could start providing more useable, activity relevant, and reliable data for everything from return to sport testing to fall risk assessments. Needless to say, I will need participants when it is time to collect data, if you are interested, please contact me via email and we can set up a time to chat! Cmj027@gmail.com

Chris is a Sports Residency and Sport Performance Trained, Doctor of Physical Therapy from the United State of America, with a unique perspective on strength and conditioning, performance, and sports injury management. Having practiced the last 9 years in outpatient sports orthopedics, Chris has recently left his position with Memorial Hermann Ironman Sports Medicine in Houston, Texas, to pursue a Masters of Philosophy (Rehabilitation Science focus) in Auckland, with AUT SPRINZ. Chris completed his sports training and education with The University of St. Augustine, The Ohio State University, and University of Louisville.

PAGE 35

CLINICAL REVIEW

Paediatric Resistance Training: Benefits, Concerns, and Program Design Considerations. Avery D. Faigenbaum and Gregory D.Myer Current Sports Medicine Reports Vol.9 No.3, pp.161-168, 2010

By Pip Sail A growing number of young athletes are involved in

resistance training program (44,65,67).

resistance training in schools, fitness centre and sports-training facilities(13,61). As more children and

Bone Health

adolescents get involved it is important to establish

Childhood and adolescence may be the opportune

safe and effective guidelines by which resistance

time to for the bone-modelling and remodelling

exercise can improve the health, fitness and sports

process to respond to tensile forces associated with

performance of younger populations.

weight-bearing

The term resistance training refers to a method of

resistance training guidelines are followed along with

conditioning that involves the progressive use of a

proper nutrition, resistance exercise can play a

wide range of resistive loads, different velocities and

critical role in bone mass acquisition during the

a variety of training modalities

paediatric years (73). The mechanical stress from

activities

(3,73).

age-specific

this type of training may act synergistically with

Resistance training can offer unique benefits for

growth-related increases in bone mass (3,73).

children when properly supervised and appropriately prescribed:

Sports-Related Injuries

a) enhanced muscle strength/power

Owing to the apparent decline in free time physical

b) enhanced motor skill performance

activities among children and adolescents (57,59), it

c) facilitate weight control

seems that the musculoskeletal system in some

d) increase bone mineral density

young athletes may not be prepared for the demands

e) increase resistance to sports related injury

of sports practice and competition.

f) increase local muscle endurance

Appropriately designed and sensibly progressed

g) improve insulin sensitivity

resistance training programs may help to reduce the

h) improve blood lipid profile

likelihood of sports related injuries in young athletes.

i) enhance attitude toward lifetime physical activity

While there is not one combination of exercises, sets and repetitions that has proven to optimise training

Body Composition

adaptations, these data indicate that multifaceted

Although the treatment of paediatric obesity is

programs that increase muscle strength, enhance

complex, exposure to resistance training along with

movement mechanics and improve functional abilities

counselling and nutrition advice may provide a safe

appear to be the most effective for reducing sports

pathway for obese youth to initiate exercise. Several

related injuries in children.

studies have reported favourable change in body composition in children and adolescents who were obese

following

participation

progressive

Special Considerations for Training Girls CONTINUED ON NEXT PAGE >>

PAGE 36

CLINICAL REVIEW While musculoskeletal growth and development

Lower back pain has become a significant health

show similar trends between genders, male and

concern among adolescents (37) and a role for

female strength and neuromuscular patterns diverge

preventative

significantly during and after puberty (31). Boys

muscular endurance and low back stability has

naturally

and

become apparent particularly in young lifters. Injuries

coordination that correlates to maturational stages

to the lower back may be in part due to poor program

whereas untrained girls show very little improvement

design,

throughout

Multifaceted

progression of loads and thus if paediatric resistance

training that combine resistance training, plyometric

trains guidelines are not followed there is potential for

training, balance and proprioception have been found

serious injury.

demonstrate

puberty

power,

strength

(31,35,43,62).

intervention

improper

enhance

technique

and

strength,

inappropriate

to enhance movement biomechanics and lower limb strength in adolescent girls (49-55). Resistance

Paediatric Resistance Training Guidelines

training combined with growth and development may

induce a â&#x20AC;&#x153;neuromuscular spurt "which may improve

administration of safe, effective and enjoyable youth

biomechanics related to injury risk (34,54) and may

resistance training program is understanding training

improve sports performance.

principles and an appreciation the uniqueness of the

prerequisite

physical

and

for

the

psychosocial

development

aspects

and

training

Risks and Concerns

children and adolescents.

Current findings indicate a low risk of injury in

There is no minimum age requirement at which

children and adolescents who follow age appropriate

children can begin resistance training but participants

training guidelines (18,24,42)

must be mentally and physically ready to comply with

Potential for injury to the physis or growth plate has

coaching instructions and the stress of an organised

been a primary concern associated with youth

training program.

resistance training. The growth plate

There

can be

does

not

appear

one

optimal

significantly weaker than the surrounding connective

combination of sets, reps and exercises that will

tissue and therefore less resistance to shear or

promote favourable adaptations in young lifters.

tensile forces (66) and injury to this section of the

Sensible integration of different training and periodic

bone can result in significant discomfort, growth

manipulation of program variable will keep the

disturbance and loss of training hours. However,

training

these injuries are generally caused by improper lifting

Individual effort combined with a well-designed

techniques, poorly designed training programs and

training program will determine the adaptations that

poorly appointed training loads combined with lack of

take place.

effective,

challenging

and

pleasurable.

qualified adult supervision.

There is no evidence to suggest that resistance

When designing resistance training programs for

training will negatively impact growth and maturation

young athletes, it is important to consider the

during childhood and adolescence (18,42).

total

While data to date indicates that injury occurrence in

practice and competition as well as free play,

paediatric resistance training is very low (18,24,42)

physical education and possibly private coaching

professional

sessions.

who

prescribe

resistance

exercise

dose,

Because

which

the

includes

sports

interindividual

should be mindful of the risk associated with this

variability of stress tolerance, each young athlete

type of training, cognisant of safety precautions and

should be treated as an individual. A reduction in

aware of the potential risk for repetitive use soft

sports performance and an increased risk of

tissue injuries.

injury can result if resistance exercises are CONTINUED ON NEXT PAGE >>

PAGE 37

CLINICAL REVIEW simply added onto a young athlete's training

Begin resistance training with two sets of 10-15

schedule.

repetitions with a light load to develop proper technique then depending on the individual needs,

Acute Program Design Variables

goals and abilities repetition loads can be progressed

Variables to be considered in designing a paediatric

to include additional sets with heavier loads, for

resistance program:

example 6-10rep max., on large muscle groups to

a) warm-up and cool-down

maximise strength gains. It is important that the

b) selection and order of exercise

number of repetitions allow the lifter to maintain

c) training intensity and volume

movement speed and efficiency for all repetitions

d) rest intervals between sets and exercises

within a set.

e) repetition velocity Research suggests that children and adolescents Warm up procedures should involve the performance

can resist fatigue to a greater extent than adults

of dynamic movement designed to elevate core body

during several repeated sets of resistance exercise

temperature,

(19). Thus a short rest interval of about a minute may

improve kinaesthetic awareness and maximise active

suffice in children. This should be decided as long as

range of movement.

technique remains good.

Select

enhance

exercises

that

motor-unit

are

excitability

appropriate

the

The cadence

at which resistance exercise is

participant's body size, fitness level, exercises

performed can affect the adaptations to a program.

technique experience and training goals. Resistance

The performance of different training velocities within

training with free weights, medicine balls and body

a program may be the most effective stimulus for

weight will be particularly beneficial for young

young athletes, however as velocity is increased it is

athletes who need to enhance motor skill, balance,

critical to retain correct technical performance of

core strength and muscle power.

each repetition.

Most youth will perform total body workouts several times per week which involve multiple exercises

CONCLUSION

stressing all major muscle groups each session. In

Scientific evidence and clinical impressions indicate

this type of workout large muscle group exercises

that resistance training has the potential offer health

should be performed before smaller muscle group

and fitness value to children and adolescents

exercises and multiple-joint exercises should be

provided that appropriate training guidelines are

performed before single joint exercises.

followed

More challenging exercises should be performed

Comprehensive resistance training programs that

earlier in the workout when the neuromuscular

integrate different elements of physical fitness are the

system is less fatigued

most likely to enhance sports performance and

and

qualified

instruction

available.

reduce the risk of injury. Training intensity is one of the most important factors in a resistance training program because it is the major stimulus

related to muscular fitness. To

reduce the risk of injury young lifters need to first learn how to perform the exercise technically with a light load and then gradually progress the intensity or volume without compromising technique.

A full list of references is available on request.

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UPCOMING SEPNZ COURSES

The second half of the year we have successfully completed The Lower Limb in Sport course, Promotion and Prescription of Physical Activity and Exercise Injury Prevention & Performance Enhancement. We have had a great turn out and we are looking forward to bringing you more next year Proposed courses for 2020 (Not limited to) Sideline Management Venue and dates TBC This course is for registered physiotherapists who work with individual athletes, or on the sideline at sports games or events who want to upskill in the areas of pregame preparation, first aid, acute injury assessment and management, and postevent recovery strategies. By the end of the course you will have all the tools you By the end of the course you will have all the tools you need to manage pre-event preparation, post-event recovery and to confidently assess, manage and refer common sporting injuries and wounds. Lower Limb in Sport SAVE THE DATE: 3rd and 4th Oct 2020 SOUTH ISLAND This course is for registered physiotherapists who work with individual athletes or teams in which lower limb injury is common. The focus of the course is on pathomechanics and kinetic chain deficits as they relate to injury prevention and performance, diagnosis and advanced rehabilitation of lower limb conditions. By the end of the course you will understand the pathoaetiology of common lower limb injuries, be able to perform key clinical and functional tests, rehabilitate lower limb injury in a number of sporting contexts including football, running and contact sports, and develop individualised return-to-sport programmes. Injury Prevention & Performance Enhancement. Venue and Dates TBC This course will provide you with the key skills used in the enhancement of sporting performance and prevention of injury. It covers the analysis of physical, biomechanical and technical needs of sport, identifying key factors affecting performance and injury prevention. You will learn how to assess athletes and implement an individualised programme designed to optimise movement efficiency, performance and minimise injury risk. You will learn how to develop a sportâ&#x20AC;&#x201C;â&#x20AC;?specific screening assessment, how to monitor injury rates and target injury prevention strategies within different sporting contexts. APA Sports Physiotherapy Level One Course. SAVE THE DATE: March 21st-22nd, 2020 SEPNZ is excited to have partnered the Sports and Exercise Physiotherapy Australia (SEPA) and the Australian Physiotherapy Association (APA), to bring the APA Sports Physiotherapy Level One course to New Zealand. The course will be taken by highly experienced and world renowned Mark Brown and Maria Constantinou. This course will suit recent graduates looking to expand their sports physiotherapy knowledge and apply their undergraduate knowledge into a sports setting and more experienced Physios wanting to build on existing knowledge and refresh their sports physiotherapy skills. This course can be done in isolation or as part of the pathway towards becoming an APA Titled Physiotherapist Watch this space, more details to come.

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RESEARCH PUBLICATIONS

British Journal of Sports Medicine November 2019; Vol. 53, No. 22 CONSENSUS STATEMENT ORIGINAL ARTICLES It is good to feel better, but better to feel good: whether a patient finds treatment ‘successful’ or not depends on the questions researchers ask (9 May, 2019) Ewa M Roos, Eleanor Boyle, Richard B Frobell, L Stefan Lohmander, Lina Holm Ingelsrud Online multifactorial prevention programme has no effect on the number of running-related injuries: a randomised controlled trial (6 April, 2019) Tryntsje Fokkema, Robert-Jan de Vos, John M van Ochten, Jan A N Verhaar, Irene S Davis, Patrick J E Bindels, Sita M A Bierma-Zeinstra, Marienke van Middelkoop EDITORIALS Exercise trials for blood pressure control: keeping it REAL (7 June, 2019) SallieAnne Pearson, Nicholas Buckley, Emmanuel Stamatakis

Keep calm and carry on testing: a substantive reanalysis and critique of ‘what is the evidence for and validity of return-to-sport testing after anterior cruciate ligament reconstruction surgery? A systematic review and metaanalysis’ (9 July, 2019) FREE

Imaging with ultrasound in physical therapy: What is the PT’s scope of practice? A competency-based educational model and training recommendations Jackie L Whittaker, Richard Ellis, Paul William Hodges, Cliona OSullivan, Julie Hides, Samuel Fer nandez-Carnero, Jose Luis Arias-Buria, Deydre S Teyhen, Maria J Stokes REVIEWS Knee osteoarthritis risk is increased 4-6 fold after knee injury – a systematic review and meta-analysis (9 May, 2019) FREE Erik Poulsen, Glaucia H Goncalves, Alessio Bricca, Ewa M Roos, Jonas B Thorlund, Carsten B Juhl Hamstring rehabilitation in elite track and field athletes: applying the British Athletics Muscle Injury Classification in clinical practice (12 July, 2019) Ben Macdonald, Stephen McAleer, Shane Kelly, Robin Ch akraverty, Michael Johnston, Noel Pollock

Jacob John Capin, Lynn Snyder-Mackler, May Arna Risberg, Hege Grindem DISCUSSION Should this systematic review and meta-analysis change my practice? Part 1: exploring treatment effect and trustworthiness (8 April, 2019)

Mervyn J Travers, Myles Calder Murphy, James Robert Debenham, Paola Chivers, Max K Bulsara, Matthew K Bagg, Thorvaldur Skulli Palsson, William Gibson Should this systematic review and meta-analysis change my practice? Part 2: exploring the role of the comparator, diversity, risk of bias and confidence (8 April, 2019) Mervyn J Travers, Myles Calder Murphy, James Robert Debenham, Paola Chivers, Max K Bulsara, Matthew K Bagg, Thorvaldur Skulli Palsson, William Gibson

http://bjsm.bmj.com/content/53/23 All articles are accessible via our website https://sportsphysiotherapy.org.nz/members/bjsm/

PAGE 40

CLASSIFIEDS

PAGE 41

COURSE EDUCATORS

EXPRESSION OF INTEREST The SEPNZ Education Committee is calling for expressions of interest for new members to join

the SEPNZ Education Committee. We are looking for people needed for teaching course content or just manpower for decision making If you have a passion for Sports Physiotherapy and an interest in helping our members receive quality robust Sports Physiotherapy education, please send your CV along with a covering letter to: Rebecca Longhurst becsvw@hotmail.com

SEPNZ Bulletin December 2019

Articles inside

CLINICAL REVIEW: Paediatric Resistance Training: Benefits, Concerns, and Program Design Considerations

By SEPNZ President Blair JarrattEDITORIAL

FEATURE ARTICLE: ACL reconstruction return to soccer: Strength or Func

Rate of Force Development (RFD) by Chris Juneau SPRINZ

The Ottawa Rules AppAPP REVIEW

ASICS Sports Medicine Australia Conference 2019CONFERENCE REPORT

Dual Density MidsolesASICS ARTICLE

Emma LatteyGET TO KNOW YOUR EXEC

DiscountsMEMBER BENEFITS