Kinematic and electromyographic analysis of wheelchair propulsion on ramps of different slopes for young men with paraplegia.

OBJECTIVE

To gain insight into the biomechanics of upslope wheelchair stroking by examining the changes in kinematic and electromyographic characteristics of wheelchair propulsion over ramps of different slopes.

DESIGN

Repeated-measures design. Each subject pushed up a wooden ramp (7.3m long) 3 times at self-selected normal and fast speeds for each of these slopes: 0 degrees , 2 degrees , 4 degrees , 6 degrees , 8 degrees , 10 degrees , and 12 degrees .

SETTING

A biomechanics laboratory.

PARTICIPANTS

Young men (N=10) with paraplegia.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Electromyographic activity of extensor carpi radialis, triceps brachii, antero-middle and postero-middle deltoids, pectoralis major, and latissimus dorsi, and stroking kinematics.

RESULTS

Forward lean of the trunk increased as the slope increased. The triceps brachii, antero-middle deltoid, and pectoralis major were more active during the push phase, while the postero-middle deltoid was more active during the recovery phase. Both extensor carpi radialis and latissimus dorsi were active throughout a stroke. Major adjustments in stroking kinematics and significant increases in muscle activity occurred at slopes between 4 degrees and 10 degrees .

CONCLUSION

In addition to a decrease in stroking speed, the stroking pattern becomes more compact (decreased push angle and relative recovery time, increased stroke frequency) and the trunk becomes more active with increasing slope.