Effects of four patterns of vibration combined with load on the root mean square amplitude of surface electromyogram of the lower limbs during semi-squats with the heel lifting / 中国组织工程研究

ABSTRACT

BACKGROUND: The surface electromyography can evaluate the effect of exercise by recording the parameters of muscle activities, and vibration exercise is the best supplement to traditional weight training. More research focuses on the effect of simple vibration training on the surface electromyography of lower limbs, but the influence of vibration combined with weight-bearing training is poorly understood.OBJECTIVE: To study the effect of vibration combined with load on the surface electromyography of lower limbs at the micro level of muscle working principle.METHODS: Eight healthy college students were recruited, and subjected to four different stimulations vibration (45 Hz) combined with load (45% one repetition maximum (IRM)); vibration (45 Hz) combined with load (60% 1RM); vibration (50 Hz) combined with load (45% 1RM); vibration (50 Hz) combined with load (60% 1RM), followed by semi-squat exercise with the heel lifting, 10 times/minute, for 3 courses with more than 2 hours in between.RESULTS AND CONCLUSION: Different vibrations combined with loads made significant difference on the root mean square amplitude of the surface electromyography (P < 0.01), and there was a significantly increased root mean square amplitude in the vibration (50 Hz) combined with load (45% 1RM), especially at the medial gastrocnemius. The four kinds of stimulations made significant different effects on the surface electromyography of rectus femoris, tibialis anterior, and medial gastrocnemius, except semitendinosus (P ≤ 0.05). Moreover, the effect showed significant difference among different stimulations except vibration (50 Hz) combined with load (45% 1RM) (P ≤ 0.05). Compared with the other three stimulations, vibration (50 Hz) combined with load (45% 1RM) exerted better effect on the muscular activation. To conclude, different vibrations combined with loads exert different effects on the motor unit of same neuromuscular activity, and a suitable stimulation may produce better effect. Besides, the same stimulus for the motor unit of different neuromuscular activities produces different effects, which may match to the muscle nature.