Article

The purpose of this study was to determine whether muscle balance is influenced
by fatigue in a recordable way, toward creating novel defensive activity
strategies for manual wheelchair users (MWUs). Wheelchair propulsion to a point
of mild fatigue, level 15 on the Rating of Perceived Exertion scale, was
investigated at two different speeds. Surface electromyographic (EMG) activity of
7 muscles was recorded on 14 nondisabled participants. Kinetic variables were
measured using a SmartWheel. No significant effect was found of percentage
endurance time on kinetic variables for the two propulsion speeds.
Fatigue-related changes in the EMG spectra were identified as an increase of EMG
intensity and a decrease of mean power frequency as a function of percent
endurance time for the tested muscles under both fast and slow speed conditions.
The greater increases in activity for propulsive muscles compared with recovery
muscles during fast speed wheelchair propulsion indicated muscle imbalance
associated with fatiguing wheelchair propulsion. This study shows how kinetic and
EMG information might be used as feedback to MWUs to ensure that they conduct
activity in ways that do not precipitate injury.

Langue : ANGLAIS