Current studentsExisting staffContact us
 

Relative contributions of the infraspinatus and deltoid during external rotation in patients with symptomatic subacromial impingement

Simple item page
dc.contributor.authorClisby, E.
dc.contributor.authorBitter, N.
dc.contributor.authorSandow, M.
dc.contributor.authorJones, M.
dc.contributor.authorMagarey, M.
dc.contributor.authorJaberzadeh, S.
dc.date.issued2008
dc.descriptionCopyright © 2008 Journal of Shoulder and Elbow Surgery Board of Trustees Published by Mosby, Inc.
dc.description.abstractA principal cause of subacromial impingement (SAI) is failure of the rotator cuff to center the humeral head in the glenoid during shoulder motion, counteracting the effect of the deltoid. As rehabilitation of the rotator cuff endeavors to restore balance between these muscle groups, the purpose of this companion study was to evaluate, in the symptomatic shoulders of patients with SAI, (1) the conditions of resisted isometric external rotation (ER) that optimized the contribution of the infraspinatus and (2) the load of ER at which adduction was most effective at reducing the deltoid contribution and then to compare this with the relative contribution of the infraspinatus and the posterior and middle deltoid in asymptomatic shoulders. In 14 subjects (18 shoulders) with SAI, surface electromyographic activity of the infraspinatus and the posterior and middle deltoid and pectoralis major was recorded at low, medium, and high loads of resisted isometric ER, with and without adduction. These data were normalized to find each muscle's relative contribution to the task and were compared with normalized data from subjects with healthy shoulders. In subjects with SAI, low loads of isometric ER (10%-40% maximum voluntary isometric contraction) optimized the relative contribution of the infraspinatus. Adduction with isometric ER at 10% maximum voluntary isometric contraction reduced the middle deltoid involvement. Higher loads preferentially activated the middle deltoid over the infraspinatus and may have effected unwanted humeral head superior translation, counteracting the presumed benefits of rotator cuff ER exercises. An individualized loading regimen and the use of surface electromyography may have significant implications during rotator cuff rehabilitation.
dc.description.statementofresponsibilityElizabeth F. Clisby, Natalie L. Bitter, Michael J. Sandow, Mark A. Jones, Mary E. Magarey and Shapour Jaberzadeh
dc.description.urihttp://www.elsevier.com/wps/find/journaldescription.cws_home/623149/description#description
dc.identifier.citationJournal of Shoulder and Elbow Surgery, 2008; 17(1 Supplement):87S-92S
dc.identifier.doi10.1016/j.jse.2007.05.019
dc.identifier.issn1058-2746
dc.identifier.issn1532-6500
dc.identifier.urihttp://hdl.handle.net/2440/52126
dc.language.isoen
dc.publisherMosby Inc
dc.rightsCopyright 2008 Journal of Shoulder and Elbow Surgery Board of Trustees Access Condition Notes: Postprint only available on Open Access
dc.source.urihttps://doi.org/10.1016/j.jse.2007.05.019
dc.subjectEMG
dc.subjectShoulder
dc.subjectSubacromial Impingwement
dc.titleRelative contributions of the infraspinatus and deltoid during external rotation in patients with symptomatic subacromial impingement
dc.typeJournal article
pubs.publication-statusPublished

Files

Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
9915914132301831_53109901700001831.pdf
Size:
220.41 KB
Format:
Adobe Portable Document Format
Download

Collections

Orthopaedics and Trauma publications