| Summary: | 碩士 === 國立體育大學 === 運動保健學系碩士班 === 98 === It has been shown that whole-body vibration (WBV) has a similar effect of resistance training on muscle function with its safety and time-saving benefits in particular. While muscle function degenerates since middle age, optimal vibration frequency for men in the middle-aged and older has not been well established. Thus, the purpose of the study was to investigate the effect of different whole-body vibration frequencies on lower limb muscle fiber recruitment among middle-aged and older men of different physical activity levels. Subjects were 36 healthy middle-aged and older men. They were surveyed by the International Physical Activity Questionnaire (IPAQ) and were divided into physical activity (PA) insufficient group (PAI) and PA sufficient group (PAS). Subjects underwent WBV at different vibration frequencies of 20,30,40 Hz in random order. The EMGrms was used to record muscle fiber recruitment activities of vastus lateralis, biceps femoris, tibia anterior, and gastrocnemius. The results showed that among all vibration frequencies of 20, 30, and 40 Hz in all observed muscle fibers namely vastus lateralis, biceps femoris, tibia anterior, and gastrocnemius, the most muscle fiber recruitment occurred at the vibration frequency of 20 Hz. While there was no significant difference between PAI and PAS in vastus lateralis and biceps femoris at all levels of vibration frequencies, significant higher muscle recruitment activities were observed in tibia anterior for PAI than PAS at 20 Hz, and in gastrocnemius for PAI than PAS at all levels of vibration frequencies. Findings from the present study indicated that significant more muscle fibers recruitment was observed at all vibration frequencies. More specifically, 20 Hz vibration frequency recruited the most muscle fibers, and PAI recruited significant more muscle fibers than PAS. The results provide insights in training and maintaining lower limb muscle function for fall prevention in middle-age and older sedentary men.
|
|---|
