Changes in oxygen uptake, shoulder muscles activity, and propulsion cycle timing during strenuous wheelchair exercise.
METHODS
Cross-over study.


OBJECTIVE
To determine the effect of strenuous wheelchair exercise on oxygen uptake (VO2 ), muscle activity and propulsion cycle timing (including the push time and recovery time during one full arm cycle).


METHODS
Laboratory of Sport Sciences at the University of France-Comte in France.


METHODS
Two exercise bouts of 6-min duration were performed at a constant workload: (1) non-fatigable exercise (moderate workload) and (2) fatigable exercise (heavy workload). Measurement of VO2, surface electromyographic activity (EMG) from shoulder muscles, and temporal parameters of wheelchair ergometer propulsion were collected from eight able-bodied men (26+/-4 years).


RESULTS
A progressive increase in VO2 associated with EMG alterations (P<0.05), and a decrease of the cycle and recovery time (P<0.05) during the heavy exercise. Whereas the push time remained constant, an increased muscle activation time (P<0.05) was found during heavy exercise.


CONCLUSIONS
Observations during wheelchair ergometry indicate the development of fatigue and inefficient muscle coordination, which may contribute to deleterious stress distributions at the shoulder joint, increasing susceptibility to injury.
Bernasconi
S M
SM
1EA 3920 Physiopathologie cardiovasculaire et prévention, Laboratory of Sport Sciences, University of Franche-comte, Besançon, France.
Tordi
N
N
Ruiz
J
J
Parratte
B
B
D000328:Adult; D000704:Analysis of Variance; D018592:Cross-Over Studies; D004576:Electromyography / Q000379:methods; D016552:Ergometry / Q000379:methods; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D012782:Shoulder; D013057:Spectrum Analysis; D013997:Time Factors; D014910:Wheelchairs