Neural Adaptations Associated with Locomotor Muscle Fatigue, pp. 87-107
Authors: (Stéphane Perrey, Motor Efficiency and Deficiency Laboratory, University Montpellier I, Faculty of Sports Sciences, Montpellier, France)
Abstract: It is well known that several biomechanical aspects of locomotion are altered with the onset of whole-body fatigue that can precipitate propulsive limb injuries. Significant locomotor muscle fatigue, commonly defined as an exercise-induced reduction in maximal voluntary force produced by the locomotor muscles occurs during sustained dynamic exercise. By contrast, muscle fatigue could also be considered as a positive phenomenon, which protects muscle tissue from damage that might be incurred to it by overuse. Besides studying the muscle contractile properties of the limb muscles, the recent application of noninvasive electrophysiological and brain imaging techniques revealed insights into the central control of locomotion and the neural adaptations induced by fatigue. The current review presents neurophysiological adaptations induced by fatiguing exercise and their influences on locomotor behavior. It emphasizes the plasticity of the neuromuscular system, particularly the spinal and supraspinal structures during some locomotor tasks. An understanding of the site, nature, and cause of locomotor muscle fatigue is explored. It is proposed that detecting changes in the underlying physiology of the muscle fatigue before the onset and development of an injury, may facilitate the development of effective injury prevention strategies.