Improved efficiency with a wheelchair propelled by the legs using voluntary activity or electric stimulation.

OBJECTIVE

To determine whether a new leg-propelled wheelchair provides enhanced efficiency and mobility to wheelchair users.

DESIGN

Observational; subjects were tested while wheeling with the arms and legs and while walking (where possible) for 4-minute periods in random order with approximately 10-minute rest periods between exercise sets.

SETTING

Tests were done on an indoor 200-meter track.

PATIENTS

Group 1, 13 controls; group 2, 9 persons with complete spinal cord injury (SCI); group 3, 13 persons with other motor disorders (retaining some voluntary control of the legs).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Physiological Cost Index (PCI), (computed as change in heart rate divided by velocity of movement) and oxygen consumption (VO(2))

RESULTS

Arm wheeling took significantly more effort (mean PCI =.52 beats/m) than walking (.33 beats/m) in control subjects. Leg wheeling was most efficient (.23), requiring less than half the effort of arm wheeling and 30% less effort than walking. For SCI subjects, leg wheeling with functional electric stimulation (FES) required less than half the effort (.18) of arm wheeling (.40). The FES group could not walk. Subjects in group 3 could walk, but with substantial effort (1.81) compared with arm (.76) or leg wheeling (.64). Results for VO(2) were similar.

CONCLUSIONS

Better wheelchair efficiency can be obtained for many disabled individuals, by moving the leg muscles voluntarily or with FES.