Effect of Selective Muscle Training Using Visual Emg Biofeedback on Infraspinatus and Posterior Deltoid

Abstract

We investigated the effects of visual electromyography (EMG) biofeedback during side-lying shoulder external rotation exercise on the EMG amplitude for the posterior deltoid, infraspinatus, and infraspinatus/posterior deltoid EMG activity ratio. Thirty-one asymptomatic subjects were included. Subjects performed side-lying shoulder external rotation exercise with and without visual EMG biofeedback. Surface EMG was used to collect data from the posterior deltoid and infraspinatus muscles. The visual EMG biofeedback applied the pre-established threshold to prevent excessive posterior deltoid muscle contraction. A paired t-test was used to determine the significance of the measurements between without vs. with visual EMG biofeedback. Posterior deltoid activity significantly decreased while infraspinatus activity and the infraspinatus/posterior activity ratio significantly increased during side-lying shoulder external rotation exercise with visual EMG biofeedback. This suggests that using visual EMG biofeedback during shoulder external rotation exercise is a clinically effective training method for reducing posterior deltoid activity and increasing infraspinatus activity.

The influence of various resistance loads on the ratio of activity of the external rotator muscles of the shoulder and the anterior gliding of the humeral head during external rotation exercise

“…EMG-based feedback has been used to facilitate the recruitment of the infraspinatus muscle during resistance training of shoulder external rotation 20 ) . As biofeedback is not easily accessible in all clinics, tactile detection of anterior gliding of the humeral head, either by the patient or therapist, could provide an alternative, as anterior gliding pressure correlated with the ratio of the posterior deltoid and the infraspinatus.…”

Análise eletromiográfica de músculos do complexo do ombro durante exercícios de rotação externa com faixa elástica

“…During rotator cuff prevention or rehabilitation programs, external rotation (ER) exercises are generally used to improve the RC stabilization and recruitment ability to restore the functional and arthrokinetic balance of the shoulder complex. In the literature, ER exercises have been analyzed by means of electromyographic assessment (EMG) 2,3,[11][12][13] . Although the literature presents several studies evaluating ER exercise, they still have limitations.…”

“…Another relevant aspect is that studies evaluating EMG activity during ER exercises usually with a dumbbell as external load [11][12][13] or perform the exercises in an isometric manner 2,3 . However, in physical therapy, external rotation exercises are commonly prescribed using elastic bands as external load 21 .…”

Electrical Stimulation to the Infraspinatus on Hypertrophy and Strength of the Shoulder

“…In recent years, several studies have researched various methods to effectively train the infraspinatus muscle [3,7,11,18]. In particular, Lim et al [18] proposed that the use of electromyogram feedback during active external rotation exercise is effective as infraspinatus training. Furthermore, Ha et al [11] recommended that external rotation with the shoulder flexed at 90 ° in a side-lying posture was effective as a selective activation of the muscle.…”