Article

The aim of this study was to investigate how the coordination patterns of
shoulder muscles change with level-ground and incline wheelchair propulsion.
Wheelchair kinetics and electromyography (EMG) activity of seven muscles were
recorded with surface electrodes for 15 nondisabled subjects during wheelchair
propulsion on a stationary ergometer and wooden ramp
(4 degree slope). Kinetic
data were measured by a SmartWheel. The kinetics variables and the onset,
cessation, and duration of EMG activity from seven muscles were compared with
paired t-tests for two sessions. Muscle coordination patterns across seven
muscles were analyzed by principal component analysis. Push forces on the push
rim and the percentage of push phase in the cycle increased significantly during
incline propulsion. Propulsion condition and posture affected muscle coordination
patterns. During incline propulsion, there was more intense and longer EMG
activity of push muscles in the push phase and less EMG activity of the recovery
muscles, which corresponded with the increased kinetic data total force output
and longer push phase in the incline condition. This work establishes a framework
for developing a performance feedback system for wheelchair users to better
coordinate their muscle patterning activity.

Langue : ANGLAIS