Electromyographic Analysis of Shoulder Girdle Muscles during Common Internal Rotation Exercises

Alizadehkhaiyat, Omid and Hawkes, David and Kemp, Graham and Frostick, Simon (2015) Electromyographic Analysis of Shoulder Girdle Muscles during Common Internal Rotation Exercises. International Journal of Sports Physical Therapy, 10. pp. 645-654. ISSN ISSN 2159-2896

Electromyographic Analysis of Shoulder Girdle Muscles during Common Internal Rotation Exercises.pdf - Submitted Version

Download (122kB) | Preview


Background: High level throwing performance requires the development of effective muscle activation within shoulder girdle muscles particularly during forceful internal rotation (IR) motions.

Study Design: Controlled Laboratory Descriptive Study

Purpose: To investigate activation pattern of 16 shoulder girdle muscles/muscle sub-regions during three common shoulder IR exercises.

Method: EMG was recorded in 30 healthy subjects from 16 shoulder girdle muscles/muscle sub-regions (surface electrode: anterior, middle and posterior deltoid, upper, middle and lower trapezius, serratus anterior, teres major, upper and lower latissimus dorsi, upper and lower pectoralis major; fine wire electrodes: supraspinatus, infraspinatus, subscapularis and rhomboid major) using a telemetric EMG system. Three IR exercises (standing IR at 0o and 90o of Abduction, and IR at Zero-Position) were studied. EMG amplitudes were normalized to EMGmax (EMG at maximal IR force in a standard position) and compared using one-way repeated-measures analysis of variance (ANOVA).

Results: There were significant differences in muscles’ activation across IR exercises (p<0.05–p<0.001). Rotator cuff and deltoid muscles were highly activated during IR at 90° of Abduction. Latissimus dorsi exhibited markedly higher activation during IR at Zero-Position. While upper trapezius had the highest activation during IR at Zero-Position, middle and lower trapezius were activated at highest during IR at 90o of Abduction. The highest activation of serratus anterior and rhomboid major occurred in IR at Zero-Position and IR at 90o of Abduction, respectively.

Conclusions: Studied exercises have the potential to effectively activate glenohumeral and scapular muscles involved in throwing motions. Results provide further evidence for developing rehabilitation, injury prevention, and training strategies.

Item Type: Article
Keywords: Electromyography; Internal Rotation Exercises; Rehabilitation; Shoulder Muscle Activation
Faculty / Department: Faculty of Science > School of Health Sciences
Depositing User: Richard Lawrence
Date Deposited: 15 Jan 2016 11:11
Last Modified: 15 Jan 2016 11:11
URI: https://hira.hope.ac.uk/id/eprint/650

Actions (login required)

View Item View Item