COMMONINJURIES
ENVIRONMENTALCONSIDERATIONS In addition to considering the user’s anthropometry, attention must also be given to the task and the environment in which the user will be working. Initially, a competitive product comparison is conducted to research exisiting options for the current hose nozzle market (see next page). The benefits and impediments of representative models are discussed and design opportunities are delineated from that analysis. Next the process of watering is analyzed and the dynamic muscle groups are determined by creating usage sequence diagrams. Additionally, research is conducted to determine the likely injuries and the effect of design on those injuries. Finally, conclusions are drawn from the results.
Common injuries that occur while using a hose nozzle include lower back injuries (see 1.a), carpal tunnel syndrome (see 2.b), shoulder impingement injuries (see 3.c), and tendonitis such as lateral epicondylitis (tennis elbow, see 4.d).i Lower back injuries are typically caused by stiff muscles and improper lifting technique—lifting with the back instead of with the legs. Carpel tunnel and tennis elbow injuries are the resultants of repetitive motion,ii such as sweeping a nozzle while watering the garden. Shoulder impingement injuries can also occur as the result of reptitive motion, especially for overhead movements.iii Many of these injuries could be avoided by an ergonomic design which suggests proper use and eliminates fatigue through a trigger locking device.
HOSENOZZLE
USAGESEQUENCE y
Shown below are the typical exercises performed while using a standard garden hose nozzle. The diagrams depict (1) lifting the nozzle off the ground with a distributed load from the hose itself growing as it is lifted, (2) changing the elevation of the nozzle in the y direction, (3) changing the angle of the nozzle in the x-z plane (rotate about y-axis), (4) changing the rotation of the nozzle (rotate about the x axis)
a
z
3
2
1
x
TIM TOCCI | PROF. V.P. HJELTNESS | 10 JAN 2010 IDUS 221: HUMAN FACTORS IN INDUSTRIAL DESIGN 4
erector spinae
deltoid (medial)
gluteus maximus
trapezius
c
bicep
bicep
forearm flexors hamstring
b bicep
forearm flexors
metacarpal flexors
deltoid (medial)
deltoid (posterior)
metacarpal flexors
latissimus dorsi (lats)
tricep
forearm flexors metacarpal flexors
forearm metacarpal flexors flexors d
PRODUCTCOMPARISON
Gilmour Zinc Pistol Grip
Dramm Revolver
Bon-Aire Ultimate Hose Nozzle
Orbit XL-Stream Nozzle
To understand the existing market and avoid reinventing the wheel, a simple competitive product analysis is performed. Initially I visited Home Depot to examine the tactile features of the respective nozzles. After reviewing their physical properties and basic functionality, I continued my analysis by researching the products online to determine how users are responding to the various designs. Surprisingly, users seem to be the most disappointed in the most expensive model, suggesting that satisfaction and price are not correlated when purchasing a hose nozzle.
price user rating
$7.08 (amazon) | 3 reviews
$11.84 (amazon) | 16 reviews
$14.99 (amazon) | 191 reviews
$25.38 (amazon) | 6 reviews
materials
zinc body, brass stem
die-cast metal,fiberglass lever, elastomer grip
aluminum, stainless steel, fiberglass, rubber
metal, polymer handle
male threaded nozzle cap, trigger-lock
nine-pattern spray nozzle: fan, cone, center, jet, mist, soaker, flat, angle, and shower
five-pattern spray nozzle, two-way shut off
adjustable spray concentration and volume via rings
pros
inexpensive, conventional design leads to consistency
variety of spraying options for multiple watering tasks
triggerless design leads to reduced grip fatigue
firehose nozzle emulation leads to more control
cons
grip can be slippery when wet and become uncomfortable after long periods of use
durability concerns: powder coated finish fades, plastic inner parts wear out
no instant off
requires two hands to turn nozzle on and off
trigger requires two hands, positive user reviews
lifetime guarantee, 6 color options, positive user reviews
1-year warranty, positive user reviews
bale (u-shaped lever) helpful for arthritic gardeners, poor customer reviews
features
DESIGNOPP Current designs offer a trigger-locking function by means of a triangular wire which can be rotated to prop the handle in the open position. Unfortunately, placement of this feature requires either two hands or a long and adroit index finger. An easier locking mechanism could resemble the safety feature on a firearm, where a cylinder is positioned by either the thumb or index finger. Another solution could resemble the pinky finger loop shown above.
remarks
HOSENOZZLE TIM TOCCI | PROF. V.P. HJELTNESS | 21 JAN 2010 IDUS 221: HUMAN FACTORS IN INDUSTRIAL DESIGN
PHASE2CONCLUSIONS The results from the analysis indicate that an ergonomic garden hose nozzle should account for repetive watering motions such as sweeping, rotating, elevating, and lowering the nozzle. In consideration of these motions and common injuries associated with gardening, experiments will be conducted in phase 3 to determine the limits of these motions. Finally, competitive product analysis reveals the simplicity and durability are key consumer values.