The comparison of the shoulder muscle activation in patients with rotator cuff tear under an abduction brace among the three postures

Kazuya Okazawa1*, Naohide Takeuchi2, Naoya Kozono2, Kenichi Kawaguchi2, Sachie Noda1, Masayuki Kawaguchi1, Yasuharu Nakashima2

1Department of Rehabilitation, Kyushu University Hospital, Fukuo-ka, Japan.
2Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Background: Immobilization using an abduction brace is essential for the relaxation of the rotator cuff and scapular muscles and the prevention of a retear in patients with rotator cuff tear after arthroscopic rotator cuff repair (ARCR). However, thus far, the comparison of the scapular muscle activities has not been compared among different postures under an abduction brace in patients after ARCR.

Objectives: The purpose of our study was to compare the scapular muscle activities among the supine position, sitting position, and walking under an abduction brace before and after ARCR

Study Design: Observational, repeated measures study.

Methods: Twelve patients with full-thickness rotator cuff tears were studied. The mean patient age was 64.7 years. The scapular muscle activations of the ipsilateral limbs were measured using surface electromyography in three postures: supine position, sitting position, and walking. The integrated electromyography relative values of the upper trapezius, anterior deltoid, middle deltoid, and biceps brachii were compared preoperatively and at two weeks after ARCR.

Results: The trapezius, biceps brachii, and middle deltoid in the walking showed significantly higher integrated electromyography relative values than those in the supine position, preoperatively and at two weeks after surgery. The anterior deltoid in the sitting position had significantly higher integrated electromyography relative values than those in the supine position.

Conclusions: Postures affected the scapular muscle activities in ARCR patients under an abduction brace. Understanding the influence of posture on the scapular muscle activity after ARCR will help rehabilitation accurately and appropriately.

Keywords: shoulder muscle activation; patients; rotator cuff tear; abduction brace; three postures

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How to cite this article:
Kazuya Okazawa, Naohide Takeuchi, Naoya Kozono, Kenichi Kawaguchi, Sachie Noda, Masayuki Kawaguchi, Yasuharu Nakashima. The comparison of the shoulder muscle activation in patients with rotator cuff tear under an abduction brace among the three postures. Internal Journal of Sports Medicine and Rehabilitation, 2021; 4:14.. DOI: 10.28933/ijsmr-2020-11-2705


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