Serratus anterior and lower trapezius muscle activities during multi-joint isotonic scapular exercises and isometric contractions

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Date: Feb. 2015
From: Journal of Athletic Training(Vol. 50, Issue 2)
Publisher: Allen Press
Document Type: Report
Length: 7,942 words
Lexile Measure: 1720L

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Abstract :

Context: Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified. Objective: To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. Design: Cross-sectional study. Setting: Health Science Laboratory. Patients or Other Participants: A total of 16 uninjured, healthy, active, male college students (age= 19.5 [+ or -] 1.2 years, height = 173.1 [+ or -] 6.5 cm, weight = 68.8 [+ or -] 6.6 kg). Main Outcome Measure(s): Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise. Results: Significant interactions in electromyographic activity were observed between intensities and exercises (P Conclusions: Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited. Key Words: upper extremity, shoulder joint, overhead performance

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Source Citation   

Gale Document Number: GALE|A406051710