Scapulohumeral kinematics and neuromuscular control during scaption are associated with passive stiffness and strength of periscapular muscles in competitive adolescent swimmers
Authors: Po‐Tsun Chen 1, 2, Po‐Kai Wang 3, 4, 5, Ting‐Ting Chen 6, Ho‐Yi Tuan‐Mu 4, 7, Chih‐Hao Chiu 2, Kuan‐Lin Liu 4, 5, 8
- School of Physical Therapy, Chang Gung University, Taoyuan, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Anesthesiology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
- Sports Medicine Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
- School of Medicine, Tzu Chi University, Hualien, Taiwan
- Department of Leisure Industry and Health Promotion, National Ilan University, Yilan, Taiwan
- Department of Physical Therapy, Tzu Chi University, Hualien, Taiwan
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
Journal: Nature - Scientific Reports - January 2023, Volume 13, Article no. 725 (DOI: 10.1038/s41598-023-27920-w)
The passive stiffness and strength of periscapular muscles may affect scapulohumeral control, especially in overhead athletes due to sports-specific training. This study tried to assess the relationship between the passive stiffness and strength of periscapular muscles, scapulohumeral kinematics and neuromuscular control during scaption in swimmers.
Ten male adolescent competitive front-crawl swimmers were recruited. The passive stiffness and strength of periscapular muscles were measured in standard postures by a hand-held myotonometer and dynamometer, respectively. Surface electromyography and electromagnetic tracking systems were synchronized to record the muscle activities and scapulohumeral kinematics during scaption. Correlations between the passive stiffness or strength of periscapular muscles and the kinematics or muscle activity were examined by Spearman’s rank correlation coefficient.
The maximal strength of periscapular muscles correlated positively with the ranges of upward and external rotation of the scapula and negatively with muscle activity during scaption. Passive stiffness of periscapular muscles was associated with the downward rotation of the scapula and triggered an increase in muscle activity. Increased passive stiffness or decreased strength in the periscapular muscles may affect their role in controlling the scapular rotation and contribute to compensation from adjacent muscles.
Our findings suggest that when attempting to evaluate scapular behavior, it may be beneficial to examine muscle strength and passive stiffness of periscapular muscles.
This observational study found that the passive stiffness and maximal strength of periscapular muscles were associated with muscle activity and shoulder kinematics during the elevation or lowering phase of scaption in competitive adolescent swimmers. The training program for competitive swimmers with SD may consider the strength and stiffness of periscapular muscles in addition to the scapular kinematics. Future studies should investigate the effects of strengthening for imbalanced strength among periscapular muscles or relaxation for stiff muscles on scapular kinematics and neuromuscular controls in competitive swimmers.