Braking electric-powered wheelchairs: effect of braking method, seatbelt, and legrests.
OBJECTIVE
To examine the influence of three electric-powered wheelchair braking conditions and four wheelchair seating conditions on electric-powered wheelchair motion and Hybrid II test dummy motion. This study provides quantitative information related to assessing the safety of electric-powered wheelchair driving.


METHODS
Rehabilitation engineering comparison and ANSI/ RESNA standards testing. Convenience sample of eight different electric-powered wheelchairs. Within-chair comparisons were conducted.


METHODS
Electric-powered wheelchairs were compared under three braking scenarios (joystick release, joystick reverse, power-off) and four seating conditions (seatbelt and legrests, seatbelt and no legrests, no seatbelt but legrests, no seatbelt and no legrests).


METHODS
A rehabilitation engineering center.


METHODS
The braking distance, braking time, and braking accelerations for electric-powered wheelchairs during three braking scenarios; trunk motion, head motion, and trunk angular acceleration during three braking scenarios and four seating conditions; and number of falls from the wheelchairs for three braking scenarios and four seating conditions.


RESULTS
Significant differences (p < .05) were found in braking distance, braking time, and braking acceleration when comparing the joystick release and joystick reverse scenarios with the power-off scenario. The mean braking distance was shortest with the power-off braking scenario (.89m), whereas it was longest when the joystick was released (1.66m). Significant differences (p < .05) in head displacement and trunk angular displacement were observed among braking conditions and between seating conditions. There were also significant differences (p = .0011) among braking conditions for maximum trunk angular acceleration. The Hybrid II test dummy fell from the wheelchairs with highest frequency when there were no legrests and no seatbelt used.


CONCLUSIONS
The results of this study indicate that use of a seatbelt when driving an electric-powered wheelchair reduces the risk of falling from a wheelchair. Furthermore, the use of legrests can reduce the risk of injury to the wheelchair driver. This study shows that the most abrupt braking occurs when deactivating the power switch.
Department of Rehabilitation Science and Technology, School of Health and Rehabilitation Sciences, University of Pittsburgh, University of Pittsburgh Medical Center Systems PA 15206, USA.
R A
RA
Cooper
M J
MJ
Dvorznak
T J
TJ
O'Connor
M L
ML
Boninger
D K
DK
Jones
D000058:Accidental Falls / Q000517:prevention & control*; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D004560:Electricity; D004867:Equipment Design; D006804:Ergonomics; D006801:Humans; D008348:Manikins; D009038:Motion; D012622:Seat Belts; D014910:Wheelchairs / Q000145:classification / Q000592:standards* / Q000600:supply & distribution