A Whirlwind II wheelchair, shown in the photograph, was built by a factory in Quang Ngai, Vietnam. It was first subjected to the tests described in “Simplified Strength Testing of Manual Wheelchairs in Developing Countries.” A few minor strength problems were identified and corrected.
The chair was then submitted to the VA Pittsburgh Healthcare System – University of Pittsburgh’s Human Engineering Research Laboratory for testing in accordance with the ISO International Standards for Wheelchairs.
The following test report shows that the chair passed all the Static Strength tests except that the force to pull the handgrips off the push handles was too low. It passed the fatigue tests, namely, the 200,000 cycle Two-drum test, and the 6,666 Curb Drop Test.
This indicates that the chairs that pass the “Simplified Standard Tests” have a good prospect of also passing the “ISO Wheelchair Standard Tests”. Human Engineeering Research Laboratory, University of Pittsburgh.
Human Engineering Research Laboratories
Wheelchair Standard Test Form
7180 Highland Drive
151R-1
Pittsburgh, PA 15206
(412) 365-4850
The following versions of the ISO Standards were used to perform tests on the following chair.
Name/Number: Whirlwind Wheelchair / produced in Viet Nam; Prototype
Chair Type: Manual
Contact: Dwight O. Johnson, MSME,
VIVCO Assistive Technology Services
e-mail: dwight at whirlwindwheelchair.org
ISO 01 (Static Stability) – ISO/CD 7176-1:1995-05-03 (E)
ISO 05 (Overall Dimensions) – ISO 7176-5:1986-03-01
ISO 07 (Seating Dimensions) – ISO 7176-7:Draft 1992-12-10
ISO 08 (Static, Impact, Fatigue) – ISO 7176-8:Draft 1996-05-09
The test values disclosed represent values based upon the testing of one wheelchair. These values represent the maximum performance without failure as tested on a new wheelchair. The performance that a wheelchair rider would obtain from a specific wheelchair may vary,depending upon environmental conditions and personal wheelchair riding habits.
Contact: Rory A. Cooper, Ph.D.
Director, Human Engineering Research Laboratories
Tel: (412) 365-4850
Acknowledgements
Whirlwind Wheelchair International is grateful to the Human Engineering Research Laboratories at the University of Pittsburgh for conducting the tests as a donation toward development of high quality of wheelchairs that can be built in Developing countries. HERL can be contacted by e-mail at: by e-mail: rcooper+@pitt.edu or through its web site at Healthcare System – University of Pittsburgh’s HERL.
The chair did not have adjustments
Static Stability ISO/CD 7176-1
| Stability Direction | Most Stable | Least Stable |
| Forward (Downhill) | 24.4º | na |
| Rear (Uphill) Wheels locked | 5.8º | na |
| Rear (Uphill) Wheels unlocked | 11.7º | na |
| Lateral | 15.0º | na |
Determination of overall dimensions, Mass, and Turning Space ISO 7176-5
| Stability Direction | 1015mm |
| Forward (Downhill) | 630mm |
| Rear (Uphill) Wheels locked | 320mm |
| Rear (Uphill) Wheels unlocked | 810mm |
| Largest component Dimensions: | No quick release components |
| Volume | .288 cubic meters |
| Total Mass | 18.4kg |
Seating and Wheel Dimensions ISO 7176-7
| Seat Plane Angle | 17.5º |
| Effective Seat Depth | 470mm |
| Maximum Seat Width | 400mm |
| Effective Seat Width | 390mm |
| Seat Surface Height | 460mm |
| Backrest Angle | 17.9º |
| Backrest Height | 380mm |
| Backrest Width | 360mm |
| Seat to Footrest Height | 420mm |
| Footrest Clearance | 75mm |
| Footrest Length | 120mm |
| Footrest Angle | 21.0º |
| Leg to Seat Surface Angle | 93.8º |
| Armrest Height | 250mm |
| Front of Armrest to Backrest | 370mm |
| Armrest Length | 490mm |
| Armrest Width | 20mm |
| Armrest Angle (Radius) | 400mm |
| Distance Between Armrests | 390mm |
| Front Location of Armrests | 370mm |
| Hand Rim Diameter | 450mm |
| Propelling Wheel Diameter | 610mm |
| Horizontal Location of Wheel Axle | 0 |
| Vertical Location of Wheel Axle | 110mm |
Requirements for Static, Impact, and Fatigue Strengths ISO 7176
Static Strength
| Static Strength Test | Pass/Fail |
| 760N Downward Force on Armrest | Pass |
| 1000N Outward Pull on Handgrips | Fail |
| 1000N Downward Force on Footrest | Pass |
| 1000N Downward Force on Tipping Lever | na |
| 440N Upward Force on Footrest | Pass |
| 1760N Up on Push Handles | Pass |
Impact Strength
| Impact Strength Test | Pass/Fail |
| Backrest Impact | Pass |
| Handrim Impact | Pass |
| Castor Impact | Pass |
| Footrest Lateral Impact | Pass |
| Footrest Longitudinal Impact | Pass |
Fatigue Strength
| Fatigue Test | Cycles Completed |
| Two – Drum Test | 200,000 |
| Two – Drop Test | 6666 |
Comments Concerning Two-Drum Test: The chair sustained no significant damage during the two-drum test.
149,906/200,000 Cycles: Flat tire right side/repair restart
153,294/200,000 Cycles: Flat tire right side/repair restart
161,539/200,000 Cycles: Flat tire right side/repair restart
193,909/200,000 Cycles: Flat tire right side/repair restart
6666/6666 Cycles: The chair sustained no significant damage during the curb drop test except for a bent rim caused by a flat tire.
34/6666 Cycles: Flat tire right side/repair restart
1134/6666 Cycles: Flat tire right side/repair restart: rim bent; replace and restart
General Comments:
The front caster wheel discs bent somewhat during testing, but did not adversly effect the performance of the chair.