Impairment in postural control is greater when ankle plantarflexors and dorsiflexors are fatigued simultaneously than when fatigued separately
Impairment in postural control is greater when ankle plantarflexors and dorsiflexors are fatigued simultaneously than when fatigued separately
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DOI：
10.1016/j.gaitpost.2011.05.009
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发表时间：
2011-06-01
期刊：
影响因子：
2.4
通讯作者：
Bilodeau, Martin
中科院分区：
文献类型：
--
作者：
Boyas, Sebastien;Remaud, Anthony;Bilodeau, Martin
本研究的目的是比较跖屈肌（PFs）和背屈肌（DFs）同时疲劳与单独疲劳时踝关节肌肉疲劳对姿势控制的影响。本研究还探讨了疲劳后姿势控制的恢复情况。16名成年人（8名女性和8名男性）在等速疲劳任务之前和之后进行了姿势试验，包括(i)仅PFs(30度s(-1)), （ii）仅DFs(120度s(-1))，或（iii）同时进行PFs和DFs。疲劳任务包括重复最大收缩，直到产生的扭矩下降到最大扭矩的50%以下。体位试验持续30秒，单腿开眼（EO）或闭眼（EC）。从压力位移中心计算摇摆区，中外侧（ML）和前后（AP）位置和速度。对于EO，没有发现疲劳对姿势变量的影响。随着EC的增加，只有当PFs和DFs同时疲劳时，摆动面积和AP速度才会增加。只有当两个肌肉群同时疲劳时，才会出现疲劳的影响，这可能是由于激动剂和拮抗剂肌肉之间的代偿活动受损和/或由于疲劳肌肉数量增加而导致本体感觉更大的减少。此外，当PFs和DFs同时疲劳时，摆动面积和AP速度在2分钟内恢复到疲劳前的值，而AP位置的后移持续了10分钟。最后的结果可能表明，为了达到最佳的姿势控制，需要更持久的姿势策略改变。(C) 2011 Elsevier B.V.版权所有
The aim of the present study was to compare the effects of ankle muscle fatigue on postural control when plantarflexors (PFs) and dorsiflexors (DFs) are fatigued simultaneously compared with separately. This study also investigated the recovery of postural control after fatigue. Sixteen adults (eight women and eight men) performed postural trials before and after an isokinetic fatigue task involving either (i) only PFs (30 degrees s(-1)), (ii) only DFs (120 degrees s(-1)), or (iii) both PFs and DFs simultaneously. The fatigue task involved maximal contractions repeated until the torque produced decreased below 50% of the maximal torque. Postural trials lasted 30s and were performed on one leg with eyes open (EO) or eyes closed (EC). Sway area, medio-lateral (ML) and antero-posterior (AP) positions and velocities were calculated from the center of pressure displacements. With EO, no effect of fatigue was found on postural variables. With EC, sway area and AP velocity increased only when both PFs and DFs were fatigued simultaneously. An effect of fatigue present only when both muscle groups are fatigued simultaneously could be due to impairment in the compensatory activity between agonist and antagonist muscles and/or a greater decrease in proprioception due to a greater number of fatigued muscles. In addition, when PFs and DFs were fatigued simultaneously, sway area and AP velocity returned to pre-fatigue values within 2 min, whereas a posterior shift in AP position persisted for 10 min. This last result may suggest a longer-lasting change in postural strategy needed for optimal postural control. (C) 2011 Elsevier B.V. All rights reserved.