Abstract:

BACKGROUND: To analyze surface electromyogram data using curve fitting analysis method is still in its infancy, which is rarely reported in the research of power bicycle induced fatigue.
OBJECTIVE: To explore the changes and rules of median frequency of the lower limbs induced by power bicycles under different load, and to analyze the changes of the relevant indicators of surface electromyogram and characteristics of muscle fatigue fitting curves.
METHODS: Eight young men from Physical Education School of Soochow University were enrolled as subjects. All subjects were subjected to different load and different pedaling frequency exercises using MONARK power bicycle until they felt fatigue. At the same time, surface electromyogram signals of the rectus femoris, vastus lateralis, vastus medialis, tibialis anterior muscle, gastrocnemius medial head and lateral gastrocnemius head were collected and recorded. The data were analyzed using minitab.15 statistical software. R2 was determined according to the F test (extremely significant statistical difference, P < 0.001), and then the experimental results were analyzed using the curve fitting method.
RESULTS AND CONCLUSION: (1) Under the 150 W power bicycle movement, the muscle fatigue increased with time and then trended to decrease. (2) Under the 300 W power bicycle movement, the muscle fatigue decreased with time, then showed an increasing trend and finally decreased with time. (3) Under the 150 W power bicycle movement, the fitting curve was a three-item curve, indicating there were three main factors affecting muscle fatigue. However, under the 300 W power bicycle movement, the fitting curve was a two-item curve, indicating there were two main influential factors for muscle fatigue.

Key words: tissue construction, basic experiments in tissue construction, movement, lower limbs, surface electromyogram, power bicycle, different loads, median frequency, fatigue, fitting curves, muscle, biomechanics