The relationship between extrinsic factors and acromiohumeral distance

Mackenzie, TA; Herrington, LC; Funk, L; Horsley, I; cools, A

Abstract

Background: Maintenance of the subacromial space is important in impingement syndromes. Research
exploring the correlation between biomechanical factors and the subacromial space would be beneficial.
Objectives: To establish if relationship exists between the independent variables of scapular rotation,
shoulder internal rotation, shoulder external rotation, total arc of shoulder rotation, pectoralis minor
length, thoracic curve, and shoulder activity level with the dependant variables: AHD in neutral, AHD in
60° arm abduction, and percentage reduction in AHD.
Design: Controlled laboratory study.
Method: Data from 72 male control shoulders (24.28years STD 6.81 years) and 186 elite sportsmen's
shoulders (25.19 STD 5.17 years) were included in the analysis. The independent variables were quantified
and real time ultrasound was used to measure the dependant variable acromio-humeral distance.
Results: Shoulder internal rotation and pectoralis minor length, explained 8% and 6% respectively of
variance in acromio-humeral distance in neutral. Pectoralis minor length accounted for 4% of variance in
60° arm abduction. Total arc of rotation, shoulder external rotation range, and shoulder activity levels
explained 9%, 15%, and 16%e29% of variance respectively in percentage reduction in acromio-humeral
distance during arm abduction to 60°.
Conclusion: Pectorals minor length, shoulder rotation ranges, total arc of shoulder rotation, and shoulder
activity levels were found to have weak to moderate relationships with acromio-humeral distance. Existence
and strength of relationship was population specific and dependent on arm position. Relationships
only accounted for small variances in AHD indicating that in addition to these factors there are
other factors involved in determining AHD.

Citation

Mackenzie, T., Herrington, L., Funk, L., Horsley, I., & cools, A. (2016). The relationship between extrinsic factors and acromiohumeral distance. Manual Therapy, 23, 1-8. https://doi.org/10.1016/j.math.2016.02.005

• Journal Article Type: Article
• Acceptance Date: Feb 14, 2016
• Online Publication Date: Feb 24, 2016
• Publication Date: Feb 24, 2016
• Deposit Date: Jul 26, 2016
• Journal: Manual Therapy
• Print ISSN: 1356-689X
• Electronic ISSN: 1532-2769
• Publisher: Elsevier
• Volume: 23
• Pages: 1-8
• DOI: https://doi.org/10.1016/j.math.2016.02.005
• Publisher URL: http://dx.doi.org/10.1016/j.math.2016.02.005
• Related Public URLs: http://www.journals.elsevier.com/manual-therapy/