title: Shoulder Joint and Muscle Characteristics Among Weight-Training Participants With and Without Impingement Syndrome.
abstract: Kolber, MJ, Hanney, WJ, Cheatham, SW, Salamh, PA, Masaracchio, M, and Liu, X. Shoulder joint and muscle characteristics among weight-training participants with and without impingement syndrome. J Strength Cond Res 31(4): 1024-1032, 2017-Subacromial impingement syndrome (SIS) has been reported as an etiological source of shoulder pain among weight-training (WT) participants; however, a paucity of evidence exists to describe intrinsic risk factors. The purpose of this study was to investigate specific risk-related joint and muscle adaptations among WT participants identified as having SIS based on a previously validated clinical testing cluster. Fifty-five men (mean age 27.3 years) who participated in recreational WT a minimum of 2 d·wk were recruited, including 24 individuals with SIS and 31 without SIS serving as controls. Active range of motion (AROM), bodyweight-adjusted strength values, and strength ratios were compared between groups. Significant differences were present as WT participants with SIS had decreased internal and external rotation AROM (p ≤ 0.016) and decreased bodyweight-adjusted strength values of the external rotator and lower trapezius musculature (p ≤ 0.02) when compared with WT participants without SIS. Select strength ratios were greater in the SIS group (p ≤ 0.004) implying agonist to antagonist muscle imbalances. The impaired joint and muscle characteristics identified among WT participants with SIS are not without consequence, as they are associated with shoulder disorders in both general and athletic populations. Practical applications for these findings may reside in exercise prescription that addresses internal rotation mobility, mitigates training bias, and favors muscles responsible for stabilization, such as the external rotators and lower trapezius. Strength and conditioning professionals should consider risk-related adaptations associated with WT when prescribing upper-extremity exercises.
authors.affiliation: 1Department of Physical Therapy, Nova Southeastern University, Fort Lauderdale, Florida; 2Program in Physical Therapy, Doctor of Physical Therapy Program, Department of Health Professions, University of Central Florida, Orlando, Florida; 3Pre-Physical Therapy Program, Division of Kinesiology and Recreation, California State University Dominguez Hills, Carson, California; 4Physical Therapy Division, Department of Orthopedic Surgery, Duke University School of Medicine, Durham, North Carolina; 5Department of Physical Therapy, Long Island University, Brooklyn, New York; and 6Department of Health Management and Informatics, University of Central Florida, Orlando, Florida.
authors.forename: Morey J
authors.initials: MJ
authors.lastname: Kolber
authors.forename: William J
authors.initials: WJ
authors.lastname: Hanney
authors.forename: Scott W
authors.initials: SW
authors.lastname: Cheatham
authors.forename: Paul A
authors.initials: PA
authors.lastname: Salamh
authors.forename: Michael
authors.initials: M
authors.lastname: Masaracchio
authors.forename: Xinliang
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D001835:Body Weight; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology; D019534:Shoulder Impingement Syndrome / Q000503:physiopathology*; D012785:Shoulder Joint / Q000502:physiology*; D064171:Superficial Back Muscles / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology*