Electromyographic activity and scapular dyskenesia in athletes with and without shoulder impingement syndrome

Abstract

The objective of this study was to evaluate the presence of scapular dyskinesis and pain, satisfaction and function levels, as well as analyze the activation of scapular stabilizing muscles during isometric tasks of shoulder abduction in athletes with and without SIS. Thirty men athletes were divided into two groups: SIS group and Control group. The volunteers answered the Penn Shoulder Score questionnaire translated into Portuguese, which evaluates pain, dysfunction, and satisfaction with the shoulder. They were also evaluated for the presence of scapular dyskinesis through the Slide Scapular Lateral Test. The electromyographic activity of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) muscles was evaluated during the isometric shoulder abduction in the frontal and scapular planes at angles of 45º, 90°, and 120°. The SIS group had a higher indication of pain and scapular dyskinesis when compared to control group. In the SIS group, higher values of electromyographic ratios between UT/LT and UT/SA were observed in the frontal plane in relation to the scapular plane. The conclusion can be made that pain, scapular dyskinesis, and altered muscle activation pattern was more frequent in the SIS group compared to the Control group. Therefore, exercises that emphasize the scapular muscles should be considered when

planning rehabilitation programs for the SIS.