Objective To investigate changes of muscle activation in the lower limbs during landing impact as running fatigue pro-gresses.Methods From November to December,2022,eleven male runners were recruited from Wuhan Sports University.They performed a steady-state run at 75%of their maximum heart rate and continued until Borg rating score≥17 or 90%of their maximum heart rate.Muscle activity data were collected using a Delsys wireless surface electromy-ography system,continuously recording the EMG of the quadriceps(vastus medialis,rectus femoris,vastus later-alis),hamstrings(biceps femoris,semitendinosus),gluteus maximus,lateral head of the gastrocnemius and tibia-lis anterior.The pre-activation,post-activation and co-activation characteristics of these lower limb muscles were analyzed.Results With fatigue accumulation during running,significant differences were observed in the pre-activation level of the tibialis anterior among different fatigue points(F=2.955,P=0.048),with the 100%fatigue point showing significantly higher pre-activation levels than the start(P=0.010);as well as post-activation levels of quadriceps(F=6.609,P=0.001),with higher levels at the 100%point compared to the start(P=0.011),33%(P=0.009)and 67%(P=0.043)fatigue points;co-activation ratios of ankle joint during the pre-activation phase(F=3.287,P=0.034),with a significantly higher co-activation ratio at the 100%fatigue point compared to the start(P=0.023).Conclusion As running fatigue accumulates,the central nervous system adjusts the activation levels of various lower limb muscles to modify impact posture,reducing the risk of injury from accumulated lower limb loads.
关键词
跑步/运动疲劳/表面肌电/神经肌肉控制
Key words
running/exercise fatigue/surface electromyography/neuromuscular control