Research on Effect of Motor Experience on Neuro-muscular Control Strategies during Sprint Starts
Objective:To investigate the effect of exercise experience on muscle synergy character-istics during the start and to analyze the relationship between muscle synergy and postural stabili-ty under different exercise experiences.Methods:Kinematic,ground reaction force and surface electromyography(sEMG)data of 11 high-level sprinters and 14 beginner sprinters at the start were synchronously collected using a 3D motion capture system,a 3D force plate and a wireless sEMG acquisition system.The sEMG envelopes of the two groups of subjects were mapped to the α-motor neuron pools in each segment of the spinal cord to obtain the motor output at the spinal cord level,and the muscle synergy characteristics of the two groups of subjects were obtained by using non-negative matrix factorization(NMF)and K-Means clustering.The relationship between muscle synergy variability and fluctuations in lateral displacement of mass center in each group was established based on uncontrolled manifold(UCM)analysis.Results:1)The output of L1 to L3 segments in the high-level group was significantly different from that of the low-level at the start(P＜0.05),and the output of L4 to S3 segments in the high-level group was significantly higher than that of the low-level group at the end of the start(P＜0.05);2)the spatial structure of the muscle synergies of each group was more reasonable and the activation time was more con-centrated in the high-level group(P＜0.05);3)the high-level group had a higher degree of coordi-nation among the synergies at the start,while the low-level group had a better coordination among the muscle synergies only in the preparatory stance.Conclusions:Exercise experience optimized coordination between muscle synergies and the spatio-temporal structure within each synergy.Ra-tionalization of muscle activation strategies in the preparatory stance and improvement of the start-er's starting technique can contribute to the athletic performance at the start.
NETL
NSTL
万方数据
维普
