Musculoskeletal systemстатья из журнала
Аннотация: Aim] We have reported that a motor unit of low recruitment threshold showed an abrupt increase in signal amplitudes when contiguously activated voluntarily for 10 min.The history of this increase remained beyond successive rest periods of up to 25 min duration to potentiate MUMS induced by a train of activation.To evaluate the decay process of this history, we studied MUMS amplitudes after the contiguous activation of 10 min in the present study.[Methods] Motor unit action potentials (MUAP) and MUMS were simultaneously recorded on the end plate region of m. vastus medialis or lateralis by the use of surface electrodes and a microphone.Knee extension torque was monitored isometrically at the ankle.Subjects were requested to voluntarily fire only a single motor unit identified on the MUAP display monitor adjusting the torque just above the recruitment threshold.To evaluate the potentiation levels of MUMS amplitude before and after the 10 min contiguous activation, a test train of activation of 10 s duration was elicited.Evaluation after the contiguous activation repeated every 5 min up to 25 min.[Results & Discussion] With 11 repetitive trials on a particular MU, the potentiation levels of MUMS evaluated by the test train (ranging from 2.1 to 6.8 times) correlated well (r2=0.93)with the potentiation levels evaluated during the 10 min contiguous activation (ranging from 3 to 15 times.MUMS of the test discrete activation showed no potentiation confirming our previous results.We have successfully evaluated the decaying process of the history of MUMS potentiation after 10 min contiguous activation.
Год издания: 2019
Авторы: Shigeru Morimoto, Maki Yamaguchi, Shigeru Takemori, Kazutoshi Seki, Terumasa Takahara, Hidetaka Yama- Guchi, Sho Onodera, Weida Lyu, Yuta Kojima, Chiho Fukusaki, Naokata Ishii
Источник: The Journal of Physical Fitness and Sports Medicine
Ключевые слова: Musculoskeletal Disorders and Rehabilitation
Открытый доступ: gold
Том: 8
Выпуск: 6
Страницы: 278–296