Impact of a pushrim-activated power-assisted wheelchair on the metabolic demands, stroke frequency, and range of motion among subjects with tetraplegia

Objectives: To determine differences in metabolic demands, stroke frequency, and upper-extremity joint range of motion (ROM) during pushrim-activated power-assisted wheelchair (PAPAW) propulsion and traditional manual wheelchair propulsion among subjects with tetraplegia. Design: Repeated measures. Setting: A biomechanics laboratory within a Veterans Affairs medical center. Participants: Fifteen full-time manual wheelchair users who had sustained cervical-level spinal cord injuries. Interventions: Participants propelled both their own manual wheelchairs and a PAPAW through 3 different resistances (slight, 10W; moderate, 12W; high, 14W) on a wheelchair dynamometer. Each propulsion trial was 3 minutes long. Main Outcome Measures: Primary variables that were compared between the 2 wheelchairs were participants' mean steady-state oxygen consumption, ventilation, heart rate, mean stroke frequency, and maximum upper-extremity joint ROM. Results: When using the PAPAW, participants showed a significant (P<.05) decrease in mean oxygen consumption and ventilation throughout all trials. Mean heart rate was significantly lower when using the PAPAW for the high resistance trial. Stroke frequency was significantly lower when using the PAPAW for the slight and moderate resistances. Overall joint ROM was significantly lower when using the PAPAW. Conclusions: For subjects with tetraplegia, PAPAWs reduce the energy demands, stroke frequency, and overall joint ROM when compared with traditional manual wheelchair propulsion.