Format

Send to

Choose Destination

See 1 citation in J Orthop Sports Phys Ther 2003:

J Orthop Sports Phys Ther. 2003 Mar;33(3):109-17.

Shoulder musculature activation during upper extremity weight-bearing exercise.

Author information

1
Division of Athletic Training, University of Kentucky, College of Health Sciences, Room 210C, 900 S. Limestone, Lexington, KY 40536-0200, USA. tluhl2@uky.edu

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.

PMID:
12683686
DOI:
10.2519/jospt.2003.33.3.109
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center