نوع مقاله : مقاله پژوهشی
1 کارشناس ارشد بیومکانیک ورزشی، دانشگاه آزاد اسلامی واحد کرج. کرج، ایران
2 مربی گروه تربیت بدنی، دانشگاه آزاد اسلامی واحد کرج. کرج، ایران
3 استادیار گروه تربیت بدنی، دانشگاه آزاد اسلامی واحد کرج. کرج، ایران
عنوان مقاله [English]
Backgroundand Aim: Reduced walking speed is one of the changes that occur because of the reduction in lower extremity muscle strength due to the aging process. The purpose of the present study was to examine age- and speed-related differences in the electrical activity of leg muscles between younger and older adults during walking.
Materials and Methods: In the current semi-experimental study, 15 healthy young men and 15 healthy older men, with the mean age of 26.46 and 70.3 years, respectively, were randomly selected. The electrical activities of the tibialis anterior, soleus, and gastrocnemius muscles were measured using a surface electromyographic system during walking at preferred (100%), slow (80%), and fast (120%) speeds in the Foot Flat (FF), Midstance (MSt), Terminal Stance (TSt), Initial Swing, and Terminal Swing (TSw) phases. Data was analyzed using two-way analysis of variance with repeated measures and Bonferroni tests.
Results: TheRoot Mean Squares (RMS) of the electrical activity of the gastrocnemius and soleus in the MSt and TSt phases at 80% and 120% speeds were significantly different between the groups (P<0.01). Further, the RMS of electrical activity of the tibialis anterior differed significantly between the groups (P<0.01) in the FF phase at 100% and 120% speeds, in the MSt phase at any of the 3 speeds, and in the TSw phase at 80% speed. Moreover, in the swing phases in both groups, the activity differed significantly between the 80% and 100% speeds and between the 100% and 120% speeds (P<0.001). The activities of all muscles in all stance phases differed significantly between the 80% and 120% speeds among the younger group (P<0.001) and at all speeds among the older adults (P<0.01).
Conclusion: Age-related changes in the electrical activity of the leg muscles during walking are clearly noticeable even among healthy older adults. This may be a strategy to control balance, maintain a steady metabolic state, or limit neuromuscular fatigue.