Acute effects of exercise-induced neuromuscular fatigue on postural control

点击翻译按钮获取中文摘要

OBJECTIVES The ability to control ones posture (or balance) is a prerequisite for the successful accomplishment of numerous types of activity. A bout of sustained exercise, sometimes leading to fatigue, can have a significant impact on postural control/balance. However, not all types of fatiguing activity lead to balance impairments, and the specific control features/mechanisms involved in balance that may be affected by fatigue remain largely unexplored. The main objectives of this proposed research program are to determine the effects of central and peripheral fatigue on key control features/mechanisms of standing posture, and whether these vary according to the nature/difficulty of the postural task performed and the population under study (future work). APPROACH The general approach used to address these objectives will be to first characterize and select a set of fatiguing exercises/tasks which will involve various levels of central and peripheral fatigue (years 1-2 of the proposal). This set of fatiguing tasks will then be used to provide information on the specific (postural) control features/mechanisms affected by fatigue (years 3-5). This will be achieved by contrasting the behavior of variables reflecting control features of balance between the different fatiguing tasks, but also between postural tasks of different levels of difficulty, namely: i) quiet standing, ii) reactive responses to discrete postural perturbations, and iii) reactive and anticipatory responses to continuous postural perturbations. The main variables of interest to be assessed before, during and after selected bouts of sustained exercise leading to fatigue will include measurements from force plates (ground reaction forces), measurements of body segments positions and joint angles, and muscle activity. SIGNIFICANCE The identification and understanding of factors affecting postural control/balance is important to various fields, including rehabilitation sciences (where the understanding of normal movement control is the basis for the design of interventions to address movement dysfunction), sports sciences, and others. Sustained exercise, sometimes leading to fatigue, is commonly experienced in everyday life and could interfere with optimal movement performance. However, the effect of exercise/fatigue on the control of stability/balance has not been studied systematically. This project will thus provide valuable novel information on factors important for the control of standing posture/balance.