TY - JOUR
T1 - Effects of glenohumeral rotations and translations on supraspinatus tendon morphology
AU - Nakajima, T.
AU - Hughes, R. E.
AU - An, K. N.
N1 - Funding Information:
This study was supported by grants AR41171 and HD07447 awarded by the National Institutes of Health.
PY - 2004/7
Y1 - 2004/7
N2 - Objective. The purpose of this study was to evaluate the effects of glenohumeral rotations and humeral head translations on supraspinatus tendon morphology. Design. A convenience sample of cadaver shoulders was used to measure supraspinatus tendon shape and dimensions from MRI images. Background. Epidemiological evidence has indicated that shoulder elevation and external rotation may be risk factors for rotator cuff tendon pathology, but little is known about how these postures affect tendon morphology. Methods. Measurements of supraspinatus tendon morphology were made from three-dimensional reconstructions based on T2-weighted fast spin-echo magnetic resonance images. Seven cadaver arms were imaged at neutral, 45°external and 45°internal rotations at 0°, 30°, and 60°of glenohumeral abduction. Measurements of the anterior, middle, and posterior portions of the tendon were made using ANALYZETM software. Results. The supraspinatus tendon was twisted at the muscle-tendon junction of the middle and posterior portions in 45°external and 45°internal axial rotations of the humerus, especially over 30°of abduction. Abduction over 30°shortened the entire supraspinatus tendon. External and internal rotation motions elongated the anterior and posterior portions, respectively. Conclusions. Arm posture affects morphology of the supraspinatus tendon. Relevance The results support the epidemiologic evidence linking external rotation and abduction to supraspinatus tendon disorders.
AB - Objective. The purpose of this study was to evaluate the effects of glenohumeral rotations and humeral head translations on supraspinatus tendon morphology. Design. A convenience sample of cadaver shoulders was used to measure supraspinatus tendon shape and dimensions from MRI images. Background. Epidemiological evidence has indicated that shoulder elevation and external rotation may be risk factors for rotator cuff tendon pathology, but little is known about how these postures affect tendon morphology. Methods. Measurements of supraspinatus tendon morphology were made from three-dimensional reconstructions based on T2-weighted fast spin-echo magnetic resonance images. Seven cadaver arms were imaged at neutral, 45°external and 45°internal rotations at 0°, 30°, and 60°of glenohumeral abduction. Measurements of the anterior, middle, and posterior portions of the tendon were made using ANALYZETM software. Results. The supraspinatus tendon was twisted at the muscle-tendon junction of the middle and posterior portions in 45°external and 45°internal axial rotations of the humerus, especially over 30°of abduction. Abduction over 30°shortened the entire supraspinatus tendon. External and internal rotation motions elongated the anterior and posterior portions, respectively. Conclusions. Arm posture affects morphology of the supraspinatus tendon. Relevance The results support the epidemiologic evidence linking external rotation and abduction to supraspinatus tendon disorders.
UR - http://www.scopus.com/inward/record.url?scp=3242685905&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=3242685905&partnerID=8YFLogxK
U2 - 10.1016/j.clinbiomech.2004.02.007
DO - 10.1016/j.clinbiomech.2004.02.007
M3 - Article
C2 - 15234481
AN - SCOPUS:3242685905
SN - 0268-0033
VL - 19
SP - 579
EP - 585
JO - Clinical Biomechanics
JF - Clinical Biomechanics
IS - 6
ER -