Changes in Surface Electromyography Signals and Kinetics Associated With Progression of Fatigue at Two Speeds During Wheelchair PropulsionBy Qi, Liping; Wakeling, James; Grange, Simon; Ferguson-Pell, Martin; Journal of Rehabilitation Research and Development, Volume 49, Number 1, pages 23-34
Publication Date: 2012
Study identified muscle imbalance associated with fatigue and activity of selected upper limb muscles during wheelchair propulsion. This information could be used to create novel defensive activity strategies for manual wheelchair users. Wheelchair propulsion to a point of mild fatigue was investigated at two different speeds: 0.9 meters and 1.6 meters per second. Mild fatigue was defined as level 15 on the Rating of Perceived Exertion scale. Surface electromyographic (EMG) activity of 7 muscles was recorded on 14 participants without disabilities. 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 speed conditions. The greatest increases in activity for propulsive muscles compared with recovery muscles during fast speed wheelchair propulsion indicated muscle imbalance associated with fatiguing wheelchair propulsion. Study results lead to the following recommendations: (1) avoidance of muscle imbalance, (2) strengthening of posterior musculature, (3) development of protective habits from the start of using a wheelchair, (4) communication to users of movement patterns that influence their activity positively; and (5) EMG monitoring of manual wheelchair users to help retrain correct muscle patterning.
Assistive Products Discussed: SMARTWHEEL
VA Rehabilitation Research & Development Service (Web Site: http://www.rehab.research.va.gov )
Link to text: http://www.rehab.research.va.gov/jour/2012/491/qi491.html