Altered muscle activation characteristics associated with single volitional forward stepping in middle-aged adults
Altered muscle activation characteristics associated with single volitional forward stepping in middle-aged adults
复制标题
DOI：
10.1016/j.clinbiomech.2009.06.012
复制
发表时间：
2009-11-01
影响因子：
1.8
通讯作者：
Cheng, Chih-Hsiu
中科院分区：
文献类型：
--
作者：
Chu, Yu-Hsiu;Tang, Pei-Fang;Cheng, Chih-Hsiu
背景：与年轻人相比，中年人在进行户外体育活动时摔倒的发生率更高。这项研究调查了躯干和腿部肌肉的激活模式和数量特征是否在中年人和年轻人之间有所不同。踏步是阻止跌倒的重要动作。方法：9名健康的年轻人(年龄=22[3]岁)和9名健康的中年人(年龄=52[8]岁)，每条腿进行单步、自愿、快进的踏步运动。根据脚踏切换信号，将步进运动分为起步、单腿支撑和落地三个阶段。用表面肌电图仪分析站立和摆动腿的胫前肌、腓肠肌内侧肌、股直肌、股二头肌、臀中肌和双侧竖脊肌的激活顺序、发生率、起搏潜伏期、爆发时程和标准化共收缩时程。我们将基本肌肉活动定义为在所有这些试验中表现出90%或更多的出现率。研究结果：与年轻人相比，中年人在整个踏步运动中表现出额外的几个基本爆发。中年人落地后摆动腿股二头肌和腓肠肌内侧的爆发持续时间显著延长，单腿支撑阶段站立腿的股直肌和股二头肌协同收缩时间延长(P<；0.05)。解读：健康中年人在步态相关神经肌肉控制方面存在年龄相关性改变。我们建议，专注于改善或保持与意志性腿部运动相关的神经肌肉控制的培训可能会使中年人受益，(C)2009爱思唯尔有限公司。保留所有权利。
Background: Middle-aged adults show a higher incidence of falls compared to young adults when performing outdoor physical activities. This study investigated whether or not the patterns and quantitative characteristics of the trunk and lower extremity muscle activations associated with stepping, which represents an important movement for arresting falls, differ between middle-aged adults and young adults.Methods: Nine healthy young adults (age = 22[3] years) and nine healthy middle-aged adults (age = 52[8] years), performed a single-step, volitional, fast forward stepping movement with each leg. The stepping movement was divided into the step-initiation, single-leg-support, and landing phases based on foot-switch signals. The activation sequence, occurrence rate, onset latency, burst duration, and normalized co-contraction duration of the tibialis anterior, medial gastrocnemius, rectus femoris, biceps femoris, and gluteus medius of the stance and swing legs and that of bilateral erector spinae muscles were analyzed using surface electromyography. We defined the essential muscle activation as exhibiting an occurrence rate of 90% or more in all of these trials.Findings: As compared to young adults, the middle-aged adults demonstrated several additional essential bursts throughout the stepping movement. Middle-aged adults also displayed significantly longer burst durations of the biceps femoris and medial gastrocnemius of the swing leg after landing, as well as longer co-contraction of the rectus femoris and biceps femoris of the stance leg in the single-leg-support phase (P < 0.05).Interpretation: Age-related changes in step-related neuromuscular control exist in healthy middle-aged adults. We propose that training focused on improving or maintaining neuromuscular control associated with volitional leg movements may benefit middle-aged individuals, (C) 2009 Elsevier Ltd. All rights reserved.