Shoulder musculature activation during upper extremity weight-bearing exercise
Language: 
English
Abstract: 

STUDY DESIGN: Repeated-measures design comparing 7 static weight-bearing shoulder exercises. OBJECTIVE: The purpose of this study was to determine the demand on shoulder musculature during weight-bearing exercises and the relationship between increasing weight-bearing posture and shoulder muscle activation. BACKGROUND: Weight-bearing shoulder exercises are commonly prescribed in the rehabilitation of shoulder injuries. Limited information is available as to the demands placed on shoulder musculature while these exercises are performed. METHODS: Eighteen healthy college students volunteered for this study. Surface bipolar electrodes were applied over the infraspinatus, posterior deltoid, anterior deltoid, and pectoralis major muscles. Fine-wire bipolar intramuscular electrodes were inserted into the supraspinatus muscle. Electromyographic (EMG) root mean square signal intensity was normalized to 1 second of EMG obtained with a maximal voluntary isometric contraction (MVIC). Subjects were tested under 7 isometric exercise positions that progressively increased upper extremity weight-bearing posture. RESULTS: There was a high correlation between increasing weight-bearing posture and muscular activity (r = 0.97, P < 0.01). There was relatively little demand on the shoulder musculature for the prayer and quadruped positions (2%-10% MVIC). Muscular activation was greater for the infraspinatus than for other shoulder muscles throughout most of the exercise positions tested. CONCLUSION: These results indicate that alterations of weight-bearing exercises, by varying the amount of arm support and force, resulted in very different demands on the shoulder musculature. Specifically, the infraspinatus was particularly active during the weight-bearing exercises used in this study.

Author(s): 
Uhl, Tim L.
Carver, Thomas J.
Mattacola, Carl G.
Mair, Scott D.
Nitz, Arthur J.
Item Type: 
Journal Article
Publication Title: 
The Journal of Orthopaedic and Sports Physical Therapy
Journal Abbreviation: 
J Orthop Sports Phys Ther
Publication Date: 
Mar 2003
Publication Year: 
2003
Pages: 
109-117
Volume: 
33
Issue: 
3
ISSN: 
0190-6011
DOI: 
10.2519/jospt.2003.33.3.109
Library Catalog: 
NCBI Published Medical (?)
Extra: 
PMID: 12683686

Turabian/Chicago Citation

Tim L. Uhl, Thomas J. Carver, Carl G. Mattacola, Scott D. Mair and Arthur J. Nitz. Mar 2003. "Shoulder musculature activation during upper extremity weight-bearing exercise." The Journal of Orthopaedic and Sports Physical Therapy 33: 3: 109-117. 10.2519/jospt.2003.33.3.109.

Wikipedia Citation

<ref> {{Cite journal | doi = 10.2519/jospt.2003.33.3.109 | issn = 0190-6011 | volume = 33 | pages = 109-117 | last = Uhl | first = Tim L. | coauthors = Carver, Thomas J., Mattacola, Carl G., Mair, Scott D., Nitz, Arthur J. | title = Shoulder musculature activation during upper extremity weight-bearing exercise | journal = The Journal of Orthopaedic and Sports Physical Therapy | date = Mar 2003 | pmid = | pmc = }} </ref>