کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4064863 1266228 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Age-related decreases in motor unit discharge rate and force control during isometric plantar flexion
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی ارتوپدی، پزشکی ورزشی و توانبخشی
پیش نمایش صفحه اول مقاله
Age-related decreases in motor unit discharge rate and force control during isometric plantar flexion
چکیده انگلیسی

Aging is related to multiple changes in muscle physiology and function. Previous findings concerning the effects of aging on motor unit discharge rate (DR) and fluctuations in DR and force are somewhat contradictory. Eight YOUNG and nine OLD physically active males performed isometric ramp (RECR) and isotonic (ISO) plantar flexions at 10 and 20% of surface EMG at MVC. Motor unit (MU) action potentials were recorded with intramuscular fine-wire electrodes and decomposed with custom build software “Daisy”. DR was lower in OLD in RECR-10% (17.9%, p < 0.001), RECR-20% (15.8%, p < 0.05), ISO-10% (17.7%, p < 0.01) and ISO-20% (14%, n.s.). In YOUNG force fluctuations were smaller at ISO-10% (72.1%, p < 0.001) and ISO-20% (55.2%, p < 0.05) which were accompanied with a slight increase in DR variation (n.s.). The observed lower DR in OLD is in line with earlier findings in small distal muscles. Also the larger force fluctuation in OLD was in line with previous studies with smaller hand muscles. These findings suggest that the age-related changes in MU control do exist also in large leg extensors that play an important role in human locomotion and balance control.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Electromyography and Kinesiology - Volume 22, Issue 6, December 2012, Pages 983–989
نویسندگان
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