title: The comparison of scapular upward rotation and scapulohumeral rhythm between dominant and non-dominant shoulder in male overhead athletes and non-athletes.
abstract: Previous studies have stated that the scapulohumeral rhythm dysfunction can make person prone to glenohumeral joint pathologies. The purpose of this study was to compare scapular upward rotation and scapulohumeral rhythm between dominant and non-dominant shoulder in male overhead athletes and non-athletes. Seventeen overhead athletes and seventeen non-athletes volunteered for this study. Two inclinometers were used to measure humeral abduction and scapular upward rotation in rest position, 45°, 90° and 135° humeral abduction in frontal plane. Findings indicated there was no significant asymmetry in scapular upward rotation and scapulohumeral rhythm in different abduction angles between dominant and non-dominant shoulder in non-athletes. In contrast, overhead athletes' dominant shoulders have more downward rotation in scapular rest position and more upward rotation in 90° and 135° shoulder abduction than non-dominant shoulders. Also, overhead athletes presented scapulohumeral rhythm asymmetry between dominant and non-dominant shoulder in 90° and 135° humeral abduction as dominant shoulders have less scapulohumeral rhythm ratio than non-dominant shoulders. Furthermore, overhead athletes dominant shoulders have more scapular downward rotation in scapular rest position, more scapular upward rotation in 90° and 135° humeral abduction and less scapulohumeral rhythm ratio in 45°, 90° and 135° humeral abduction than non-athletes in dominant shoulders. We suggest that clinicians should be aware that some scapular asymmetry may be common in some athletes. It should not be considered as a pathological sign but rather an adaptation to extensive use of upper limb.
authors: Department of Sport Biomechanics, Faculty of Physical Education and Sport Sciences, Bu ali Sina University, Hamadan, Iran; Department of Sport Biomechanics, Sport Science Research Center, Tehran, Iran. Electronic address: hosseinimehrhossein@gmail.com.
authors: Seyed Hossein
authors: SH
authors: Hosseinimehr
authors: Department of Sport Biomechanics, Faculty of Physical Education and Sport Sciences, Bu ali Sina University, Hamadan, Iran; Department of Sport Biomechanics, Sport Science Research Center, Tehran, Iran.
authors: Mehrdad
authors: M
authors: Anbarian
authors: Department of Sport Medicine and Corrective Exercise, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht, Iran.
authors: Ali Asghar
authors: AA
authors: Norasteh
authors: Department of Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
authors: Javad
authors: J
authors: Fardmal
authors: Department of Sport Medicine and Corrective Exercise, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht, Iran.
authors: Mohammad Taghi
authors: MT
authors: Khosravi
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000517:prevention & control*; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D007839:Functional Laterality; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D018570:Risk Assessment; D012399:Rotation; D012540:Scapula / Q000503:physiopathology; D012785:Shoulder Joint / Q000503:physiopathology*; D013177:Sports / Q000502:physiology*; D055815:Young Adult
keywords: Overhead athletes; Scapular kinematic; Scapulohumeral rhythm