Masumoto Kenji, Shono Tomoki, Takasugi Shin-ichiro, Hotta Noboru, Fujishima Kazutaka, Iwamoto Yukihide
Institute of Health Science, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan.
J Electromyogr Kinesiol. 2007 Oct;17(5):596-604. doi: 10.1016/j.jelekin.2006.06.006. Epub 2006 Aug 14.
This study aimed to examine whether walking in water produces age-related differences in muscle activity, stride frequency (SF), and heart rate (HR) response. Surface electromyography (EMG) was used to evaluate muscle activities in six older and six young subjects while they walked in water immersed to the level of the xiphoid process. The trials in water utilized the Flowmill which consists of a treadmill at the base of a water flume. The measurement of maximal voluntary contraction (MVC) of each muscle was made prior to the gait analysis. The %MVCs, which refer to the surface EMG measures, from the gastrocnemius of the older subjects were significantly lower than those of the young subjects, in every experimental condition (P<0.05). In contrast, the %MVCs from the rectus femoris (P<0.05) and the biceps femoris (P<0.001) of older subjects were significantly greater than those of young subjects in every experimental condition. Moreover, the SFs of older subjects were also significantly greater than those of young subjects (P<0.05), while the HR responses of older and young subjects were similar. In conclusion, the older subjects had increased hip musculature activity and decreased ankle plantar flexor activity while walking in water, compared with the young subjects.
本研究旨在探讨在水中行走时，肌肉活动、步频（SF）和心率（HR）反应是否存在与年龄相关的差异。在6名老年受试者和6名年轻受试者剑突水平浸入水中行走时，采用表面肌电图（EMG）评估肌肉活动。水中试验使用了Flowmill，它由水槽底部的跑步机组成。在步态分析之前对每块肌肉的最大自主收缩（MVC）进行测量。在每个实验条件下，老年受试者腓肠肌表面肌电图测量值的%MVC均显著低于年轻受试者（P<0.05）。相比之下，在每个实验条件下，老年受试者股直肌（P<0.05）和股二头肌（P<0.001）的%MVC均显著高于年轻受试者。此外，老年受试者的步频也显著高于年轻受试者（P<0.05），而老年和年轻受试者的心率反应相似。总之，与年轻受试者相比，老年受试者在水中行走时髋部肌肉组织活动增加，踝部跖屈肌活动减少。
