ABSTRACT
In shoulder arthrokinematics, the rotator cuff acts on a lower base to counterbalance a glenoid cavity, while performing a lower translation to counterbalance a rotational force mostly provided by the deltoid. External rotation (ER) exercises have been used in the rehabilitation of patients with shoulder joint dysfunction, with the aim of restoring arthrokinematics. Few studies approached the use of the elastic band and the evaluation of the shoulder girdle muscles, essential for suitable kinematics. The objective of this study was to compare the electromyographic activity (EMG) of the muscles from the shoulder complex during external rotation exercises with elastic band. A total of 11 male subjects were evaluated during (1) ER in orthostasis; (2) ER with shoulder abduction; (3) ER with lateral decubitus. The muscles assessed by the EMG were: (a) upper trapezius (UT); (b) middle deltoid (MD); (c) posterior deltoid (PD) and (d) infraspinatus (IS). Resistance was made with a gray elastic band calibrated with a load of 5% body weight. Data analysis was performed using the application software BIOMEC-SAS and statistics for the repeated measures using ANOVA in SPSS version 20.0. The UT and MD muscles were found to have increased EMG activity during ER exercise with shoulder abduction, as well as the PD muscle during ER with shoulder abduction and ER in lateral decubitus, whereas IS had increased EMG activity during an ER in orthostasis and ER in lateral decubitus.
Keywords |
Shoulder; Electromyography; Rotator Cuff; Exercise Therapy
