Effect of respiration on the static rear stability of wheelchairs.
OBJECTIVE
To test the hypothesis that the static rear stability of an occupied wheelchair is greater during full inspiration than expiration.


METHODS
Within-subject comparisons.


METHODS
Rehabilitation center.


METHODS
Able-bodied participants (N=10).


METHODS
None.


METHODS
We measured the static rear stability (brakes unlocked) of an occupied wheelchair on a test platform according to International Organization for Standardization standards. We also used the Exhalation Threshold Test. The Exhalation Threshold Test was positive if, having been positioned at the maximum degree of platform tilt needed to maintain stability during full inspiration, the wheelchair tipped backward when the participant exhaled.


RESULTS
The mean static rear stability values at full inspiration and expiration +/- SD were 16.5 degrees +/-2.3 degrees and 16.1 degrees +/-2.4 degrees , with a mean difference of .46 degrees +/-.24 degrees (3%; P=.002). The Exhalation Threshold Test was positive in 19 (95%) of 20 trials.


CONCLUSIONS
Respiration has a slight but statistically significant effect on the rear stability of occupied wheelchairs, with greater stability at full inspiration. This has potential clinical implications for stability testing and the training of wheelchair skills, but further study is needed.
Division of Physical Medicine and Rehabilitation, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada. kirby@dal.ca
R Lee
RL
Kirby
Olivier
O
Heimrath
Angela
A
Stewart
Cher
C
Smith
Donald A
DA
MacLeod
D001696:Biomechanical Phenomena; D006233:Persons with Disabilities / Q000534:rehabilitation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004869:Equipment Safety; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D014910:Wheelchairs / Q000592:standards*; D055815:Young Adult