Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks

Charles A. Thigpen, Darin A. Padua, Lori A. Michener, Kevin Guskiewicz, Carol Giuliani, Jay D. Keener, Nicholas Stergiou

Research output: Contribution to journalArticle

84 Scopus citations

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.

Original languageEnglish
Pages (from-to)701-709
Number of pages9
JournalJournal of Electromyography and Kinesiology
Volume20
Issue number4
DOIs
StatePublished - Aug 1 2010

Keywords

  • Reaching
  • Shoulder
  • Three-dimensional kinematics

Fingerprint Dive into the research topics of 'Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks'. Together they form a unique fingerprint.

  • Cite this