Document Type
Article
Publication Date
8-2010
Abstract
Forward head and rounded shoulder posture (FHRSP) is theorized to contribute to alterations in scapular kinematics and muscle activity leading to the development of shoulder pain. However, reported differences in scapular kinematics and muscle activity in those with forward head and rounded shoulder posture are confounded by the presence of shoulder pain. Therefore, the purpose of this study was to compare scapular kinematics and muscle activity in individuals free from shoulder pain, with and without FHRSP. Eighty volunteers were classified as having FHRSP or ideal posture. Scapular kinematics were collected concurrently with muscle activity from the upper and lower trapezius as well as the serratus anterior muscles during a loaded flexion and overhead reaching task using an electromagnetic tracking system and surface electromyography. Separate mixed model analyses of variance were used to compare three-dimensional scapular kinematics and muscle activity during the ascending phases of both tasks. Individuals with FHRSP displayed significantly greater scapular internal rotation with less serratus anterior activity, during both tasks as well as greater scapular upward rotation, anterior tilting during the flexion task when compared with the ideal posture group. These results provide support for the clinical hypothesis that FHRSP impacts shoulder mechanics independent of shoulder pain.
Journal Title
Journal of Electromyography and Kinesiology
Volume
20
Issue
4
First Page
701
Last Page
709
Recommended Citation
Thigpen, Charles A.; Padua, Darin A.; Michener, Lori A.; Guskiewicz, Kevin M.; Guiliani, Carol; Keener, Jay D.; and Stergiou, Nikolaos, "Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks" (2010). Journal Articles. 85.
https://digitalcommons.unomaha.edu/biomechanicsarticles/85
Tables
Comments
NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Electromyography and Kinesiology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Electromyography and Kinesiology, Vol. 20, Issue 4 (August 2010) DOI: http://dx.doi.org/10.1016/j.jelekin.2009.12.003.