Int J Sports Med 2023; 44(05): 369-375
DOI: 10.1055/a-1939-7229
Orthopedics & Biomechanics

Pitching Biomechanics and Shoulder Function in Baseball Pitchers with Scapular Dyskinesis

Tsun-Shun Huang
1   Department of Physical Therapy and Assistive Technology, National Yang Ming Chiao Tung University, Taipei, Taiwan
,
Yi-Hsuan Weng
2   School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan
,
Che-Chia Chang
3   Graduate Institute of Sports Sciences, University of Taipei, Taipei, Taiwan
,
Yung-Shen Tsai
4   Graduate Institute of Sports Equipment Technology, University of Taipei, Taipei, Taiwan
,
Jiu-jenq Lin
2   School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan
› Institutsangaben

Funding The authors acknowledged the support provided by the Ministry of Science and Technology (107–2314-B-002–033 -MY3)
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Abstract

The primary purpose was to investigate the influence of scapular dyskinesis (SD) on pitching biomechanics and shoulder function in high school baseball pitchers. The secondary purpose was to identify possible factors associated with shoulder function in pitchers with SD. Thirty-eight pitchers were classified into the SD group (n=26) or the non-SD group (n=12). They were evaluated with the Kerlan-Jobe Orthopaedic Clinic shoulder and elbow (KJOC) scale and clinical measurements of shoulder characteristics, and with measurements of scapular kinematics, muscle activation, and ball speed during fastball pitching. Compared to the controls, the pitchers with SD had less scapular external rotation (difference=11.3 degrees, ES=0.92, p=0.012) during overall pitching and less upper trapezius (UT) activation during the late cocking (difference=7.1%, ES=0.79, p=0.019) and acceleration phases (difference=12.5%, ES=0.75, p=0.035). Higher UT activation during the late cocking phase was significantly associated with higher KJOC scores (standardized β=0.415, p=0.039). In conclusion, deficits in scapular external rotation and decreased UT activation during pitching were found in pitchers with SD. Higher UT activation may be important for shoulder function in pitchers with SD.



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Eingereicht: 02. Mai 2022

Angenommen: 30. August 2022

Artikel online veröffentlicht:
17. Februar 2023

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