A Study to Compare Electromyographic Activities of Pectoralis Major and Anterior Deltoid during Shoulder Internal Rotation under Open Kinetic Chain and Close Kinetic Chain Exercise in Normal Individuals: A Cross - Sectional Observational Study

Background and objectives: One particularly vulnerable location for increased injury is the shoulder girdle. The shoulder girdle musculature provides the upper extremity with both mobility and stability. Due to the large amount of range of motion the shoulder is predisposed to overuse injuries. In the clinical setting and in the rehabilitation literature, functional activities and exercises are commonly categorized as having weight - bearing or non - weight - bearing characteristics. Another frequently used method of classifying movements and exercises is based on open or closed kinetic chain. The purpose of study was to compare the effects of open kinetic chain versus close kinetic chain exercises on muscle recruitment of the shoulder in healthy individuals. Method: 55 normal individuals with age ranging from 18 - 38 year old, who fulfilled the inclusion and exclusion criteria, were recruited by using random sampling method. EMG activity was recorded first in close kinetic chain exercise for pectoralis major and anterior deltoid muscles. Then in close kinetic chain exercise for pectoralis major and anterior deltoid muscles. Two trails were done and average of both trails was taken as consideration. Results: Data were analyzed by SPSS software 20.0; parametric Wilcoxen signed - rank test and Mann Whitney U test were used. Result shows extremely significant difference between open kinetic chain and close kinetic chain exercise. (pless than0.05). Conclusion: The study concluded that there was extremely significant difference and greater surface electromyographic activity of the pectoralis major muscle as compared to anterior deltoid muscle in open kinetic chain and close kinetic chain exercise.