Asymmetry and evolution over a one-year period of the upward rotation of the scapula in youth baseball pitchers

Journal article (2018)

Authors

E. van der Graaff Biomechanical Engineering , Vrije Universiteit Amsterdam
Bengt Kom Vrije Universiteit Amsterdam
Femke van Dis Vrije Universiteit Amsterdam
X. Gasparutto Biomechatronics & Human-Machine Control - Mechanical, Maritime and Materials Engineering
Marco Hoozemans Vrije Universiteit Amsterdam
H.E.J. Veeger Vrije Universiteit Amsterdam, Biomechatronics & Human-Machine Control - Mechanical, Maritime and Materials Engineering , Biomechanical Engineering
Research Group
Biomechatronics & Human-Machine Control (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2018 E. van der Graaff, Bengt Kom, Femke van Dis, X. Gasparutto, Marco Hoozemans, H.E.J. Veeger
DOI: https://doi.org/10.1080/23335432.2018.1499441
More Info
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Published Date

2018

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Biomechanical Engineering

Research Group

Biomechatronics & Human-Machine Control

Abstract

The pitching motion is an asymmetric action by which coordination of scapular rotation in the dominant arm might be affected in time and in comparison with the non-dominant arm. The study aimed to compare asymmetry and the evolution of scapular upward rotation over a one-year period. Data were collected twice, before and after a one-year period, from 92 participants (age = 15.1 SD 1.4 years, body height = 177.3 SD 10.9 cm, body weight 69.2 SD 14.5 kg). Scapular motion was tracked at different glenohumeral angles of elevation in the scapular plane: anatomical position (0°), 45°, 90° and 135°. Scapular upward rotation was calculated as the angle between the spinae scapula and the spine. Scapular upward rotation of the dominant arm was 5.1° (95% CI: 2.1°−8.1°) more compared to the non-dominant arm. Age group or glenohumeral angles of elevation did not affect this difference. Scapular upward rotation of the dominant arm decreased 1.9° (95% CI: −0.5° to 4.3°) after a one-year period, however, neither this observation, nor the interaction with age group or elevation angle was significant. These findings may indicate that pitchers could be at risk to develop shoulder injuries especially those that have been associated with scapular asymmetry.