Seating pressures with conventional and dynamic wheelchair cushions in tetraplegia

Objective: To compare pressure relief from a dynamic wheelchair cushion to a tilt-in-space wheelchair with conventional cushions. Study Design: Repeated measures analysis. Setting and Subjects: Spinal cord injury unit; 16 tilt-in-space wheelchair users with motor-complete tetraplegia. Main Outcome Measures: Interface pressure at ischial tuberosities. Results: Mean ischial pressure with subjects seated upright on the dynamic cushion during the low ischial pressure phase was lower than tilted pressur e on the gel cushion, but it was not significantly different from tilted pr essure on the dry-flotation cushion (dynamic/upright, 71mmHg; gel/tilted, 8 6mmHg; dry-flotation/tilted, 74mmHg; p<.05 dynamic vs gel). Mean ischial pr essure with subjects upright on the dynamic cushion during the high ischial pressure phase was significantly greater than the gel/upright and dry-flot ation/upright conditions (dynamic/upright, 157mmHg; gel/upright, 128mmHg; d ry-flotation/upright, 111mmHg;p <.01), Conclusion: The dynamic cushion produces similar pressure relief over the I schial tuberosities during the low pressure phase to a tilt-in-space wheelc hair and conventional cushions. The dynamic cushion may be an alternative t o a tilt-in-space wheelchair for some individuals. (C) 1999 by the American Congress of Rehabilitation Medicine and the American Academy of Physical M edicine and Rehabilitation.