Discussion
muscle contraction, pre-disease lesion
CONTRACTION, CORTEX
For patients after ACL reconstruction restoration to pre-injury levels of movement and function is the ultimate goalIn this study, isometric muscle strength tests were performed at 12 and 24 weeks after ACL reconstruction in both groups: the muscle strength of the quadriceps and hamstrings increased in both groups compared to the preoperative period, with the hamstrings recovering to 75% of the healthy side in the control group; the hamstrings recovered to 85% of the healthy side in the test group, which was higher than the control group.This suggests that Nordic hamstring training has a significant effect on the recovery of hamstring strength after ACL reconstruction. Nordic hamstring training is a more effective, safe and accurate form of centrifugal training than other modes of plyometric training. It moves in the opposite direction to the direction of muscle contraction, and this insurmountable resistance causes the cerebral cortex and spinal cord to send more efferent impulses to the muscle to generate more force than a centripetal contractionThe results in TableFrom TablesThe results in TableThe results of this paper show that the centrifugal moment of the quadriceps muscle also demonstrated a significant increase after 24 weeks of Nordic hamstring exercise. It has been found that the active and antagonist muscles have an interactive inhibitory effect during muscle contraction, and when the contraction of the active muscle is rapid, the antagonist muscle also experiences a synchronised contraction, and the antagonist's activity increases significantlyThe limitations of this study are as follows: (1) Only 60 subjects were included. Despite the differences between individuals, the subjects were carefully selected from 92 patients with similar age and lesions. (2) The subjects' pre-disease lesion exercise habits and exercise levels were not compared, and their influence on the experimental results was not taken into account. (3) Only isometric muscle strength tests were performed on the knee joint before, 12 and 24 weeks after the intervention, and a 4th test was not performed at a later stage to determine the long-term effects of Nordic hamstring exercise on centrifugal muscle strength and stability of the knee joint.