Kinematic comparison and description of the 3-dimensional shoulder kinematics of 2 shoulder rotation tests.
OBJECTIVE
The purpose of this study was to compare shoulder external rotation range of motion (ROM) during the hand-behind-neck (HBN) test and a standard shoulder external rotation test and to describe the 3-dimensional scapular motion during the HBN test.


METHODS
An electromagnetic tracking device was used to assess the dominant shoulder of 14 healthy participants while performing active full ROM in a standard shoulder external rotation test in an elevated position (EREP) and in the HBN test. The humeral and scapular 3-dimensional positions at the end of EREP and HBN were compared using a paired-sample t test. A correlation analysis was performed between humeral and scapular angles to assess the contribution of scapular motion to the full shoulder ROM during the HBN test.


RESULTS
No significant differences were found between the HBN test and the EREP at the end-range of the glenohumeral external rotation (HBN: 15.6° ± 6.3° vs EREP: 23.4° ± 4.7°; P = .08) and on scapular internal-external rotation (HBN test: 21.2° ± 6.3° vs EREP: 15.6° ± 1.8°; P = .23). Significant differences were found in scapular upward rotation (HBN: 21.2° ± 6.3° vs EREP: 15.6° ± 1.8°; P < .01) and scapular spinal tilt (HBN: -0.4° ± 2.3° vs EREP: 8.1° ± 2.1°; P < .01). There was a positive correlation between the humeral angles and scapular internal and posterior spinal tilt angles with the HBN test.


CONCLUSIONS
The results of the present study showed that, in young asymptomatic participants with no known shoulder pathology, the end-range of shoulder rotation was similar in the HBN test and in a standard shoulder rotation test. During the HBN test, the scapula assumed a more internal and anterior spinal tilted position at the end-range of active shoulder external rotation. These results suggest that the HBN test may be used to assess the end-range of glenohumeral external rotation.
Professor, Sports & Health Department of the Human Kinetics Faculty, University of Lisbon, Lisbon, Portugal. Electronic address: gpascoal@fmh.ulisboa.pt.
Augusto Gil
AG
Pascoal
Adjunct-Professor, School of Health Sciences, Polytechnic Institute of Leiria, Leiria, Portugal.
Nuno
N
Morais
D001696:Biomechanical Phenomena / Q000502:physiology; D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D008297:Male; D010808:Physical Examination / Q000379:methods*; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D012785:Shoulder Joint / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
Articular; Biomechanical Phenomena; Range of Motion; Shoulder