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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.
more
valuable
than
maximal
profiling individuals’ 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
related
avenues. The most commonly utilized testing
preventing a fall:
to
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
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 >>
