Elucidation of Risk Factors of Shoulder Periarticular Muscle Tear and Calcification in Masters Swimmers

Abstract

Background: Recent advancements in diagnostic imaging equipments enables us to identify the causes of pain in the rotator cuff, which has been difficult to confirm definitely. Masters swimmers often have muscle weakness and degeneration due to aging. Therefore, the localization and causes of their pain were different from top swimmers. The purpose of this study was to clarify the factors of masters swimmers’ rotator cuff pain using ultrasound, manual functional evaluation and questionnaire. Methods: Thirty-six masters swimmers (55±10.6 years old) who has shoulder pain were recruited and observed both symptomatic and asymptomatic side. The biceps brachii muscle, supraspinatus muscle, infraspinatus muscle and subscapularis muscle were visualized bilaterally by ultrasound, and edema, calcification, tear and bone deformities were documented. Orthopaedic manual evaluation of the shoulder was performed and the history of swimming and symptoms were documented. Results: The most common abnormal findings using ultrasound were edema of the biceps brachii muscles, which was found in 52.8% of all shoulders. Calcification of subscapularis and edema of infraspinatus were observed in 31.9% and 26.4%, respectively. Discussion: In this study, various abnormal findings were found on the shoulder even without symptoms. The physical evaluation results and ultrasound findings suggested an indirect relation between ultrasound findings and pain. In addition, the high rate of edema of biceps brachii and calcification of subscapularis were peculiar phenomenon unique to masters swimmers, and further research is necessary to conclude whether these abnormal findings are factors leading to retirement from the competition.