OBJECTIVE: To test the hypothesis that vision plays an important role in the maintenance of balance during a stationary wheelchair maneuver in which the wheelchair user lifts and maintains the chair's front wheels off the floor (wheelie). DESIGN: Within-subject comparisons of the ability of subjects to perform wheelies with their eyes open (EO) and their eyes closed (EC). SETTING: Kinesiologic laboratory. PARTICIPANTS: Ten able-bodied adults, a sample of convenience. MAIN OUTCOME MEASURES: Postural sway, as reflected by the standard deviation of sagittal-plane movements of the center of pressure of the chair's right rear wheel on a force platform during a 10-second stationary wheelie balance, and the number of mistrials. RESULTS: The postural sway for all trials (3 EO and EC data collections at the end of each of 3 one-hour training sessions) was 88% greater with the EC than with the EO condition (p < .001) and the number of mistrials was 324% greater (p = .001). By the end of the final training session, the postural sway with the EC (4.0cm) was still 100% greater than with the EO (2.0cm) (p < .001) although there was no longer a difference in the number of mistrials. CONCLUSION: Vision plays an important role in the maintenance of a stationary wheelie, but wheelies can be maintained with the eyes closed. These findings are relevant to the training of wheelchair users and also provide broader insights into the nature of wheelchair function and dynamic balance.
OBJECTIVE: To test the hypothesis that vision plays an important role in the maintenance of balance during a stationary wheelchair maneuver in which the wheelchair user lifts and maintains the chair's front wheels off the floor (wheelie). DESIGN: Within-subject comparisons of the ability of subjects to perform wheelies with their eyes open (EO) and their eyes closed (EC). SETTING: Kinesiologic laboratory. PARTICIPANTS: Ten able-bodied adults, a sample of convenience. MAIN OUTCOME MEASURES: Postural sway, as reflected by the standard deviation of sagittal-plane movements of the center of pressure of the chair's right rear wheel on a force platform during a 10-second stationary wheelie balance, and the number of mistrials. RESULTS: The postural sway for all trials (3 EO and EC data collections at the end of each of 3 one-hour training sessions) was 88% greater with the EC than with the EO condition (p < .001) and the number of mistrials was 324% greater (p = .001). By the end of the final training session, the postural sway with the EC (4.0cm) was still 100% greater than with the EO (2.0cm) (p < .001) although there was no longer a difference in the number of mistrials. CONCLUSION: Vision plays an important role in the maintenance of a stationary wheelie, but wheelies can be maintained with the eyes closed. These findings are relevant to the training of wheelchair users and also provide broader insights into the nature of wheelchair function and dynamic balance.