Electromyograph Analysis during Isokinetic Testing of Shoulder Joint in Elderly People

Abstract

This study aimed to analyze the muscular activity associated with the proper function, stability, and mobility of the shoulder joint. In the field of orthopedics, the shoulder joint is recognized as having extensive mobility. Using an electromyograph (sEMG), the muscular activity in 10 elderly male subjects was analyzed during joint movements while performing isokinetic exercises. The muscular activity of an agonist was analyzed using both the percent maximum voluntary contraction (%MVC) and the EMG (µV) value before normalization. The %MVC quantified four motions (flexion, extension, abduction, and adduction) for the 10 upper limb muscles whereas the latter did not. The results showed that the pectoralis major (clavicular insertion) activated as an agonist during abduction and adduction. A comparison of when the muscles activated based on each motion revealed that the middle deltoid muscle activated the fastest during abduction. This research is expected to facilitate measurement of the shoulder function for both rehabilitation equipment and their associated programs.

Keywords

• shoulder joint
• surface electromyograph (semg)
• isokinetic test
• muscle activity
• upper limb