Relationships among cushion type, backrest height, seated posture, and reach of wheelchair users with spinal cord injury.
BACKGROUND
Seated posture and trunk control are important factors affecting upper extremity (UE) function of wheelchair users. A stable pelvis and trunk are required to provide a base from which UE movement occurs, but, conversely, the ability to move one's trunk and pelvis can increase functional ranges of motion. For wheelchair users, balancing sufficient trunk support with adequate trunk mobility has important functional and medical consequences.


OBJECTIVE
To determine the effect of cushion and backrest height on posture and reach and to determine the relationship between posture and UE reach using a randomized 2 x 3 repeated-measures factorial design.


METHODS
Twenty-two subjects with spinal cord injury were tested in 6 configurations, including 3 types of cushions (segmented air, contoured viscous fluid/foam, and air/foam) and 2 of 3 backrest heights (referenced to T12, inferior scapular angle, and scapular spine) while performing unilateral and bilateral reaching tasks. Seated posture (pelvic tilt and torso angle) and American Spinal Injury Association (ASIA) score were also measured.


RESULTS
Pelvic tilt and ASIA score were significant predictors of reach. No evidence was found indicating cushion type or backrest height affected reach or posture. No consistent patterns of posture were found across cushion types or backrest heights.


CONCLUSIONS
The posture adopted by wheelchair users is a more important influence on UE reach than are the cushion or backrest height used. Sitting with increased posterior pelvic tilt enhanced stability and permitted greater reach. Because individuals adopt different postures when using different cushions and backrest heights, clinicians should monitor posture while assessing seating and function of wheelchair users.
Research Center for Rehabilitation Technology, Helen Hayes Hospital, West Haverstraw, New York, USA. sprigle@arch.gatech.edu
Stephen
S
Sprigle
Mary
M
Wootten
Zimi
Z
Sawacha
Gregory
G
Thielman
Gregory
G
Theilman
D000293:Adolescent; D000328:Adult; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013909:Thorax / Q000502:physiology; D034941:Upper Extremity / Q000502:physiology*; D014910:Wheelchairs