PNF and Movement 2024; 22(1): 151-158
Comparison Among Shoulder Diagonal Pattern of Exercises Considering Phase of Contraction Based on Muscle Activity
Soo-Han Kim, P.T., Ph.D.1⋅Se-Yeon Park, P.T., Ph.D.2†
1Department of Physical Therapy, Kaya University
2Department of Physical Therapy, Uiduk University
Correspondence to: Se-Yeon Park (
Received: April 2, 2024; Revised: April 5, 2024; Accepted: April 8, 2024; Published online: April 30, 2024.
© Korea Proprioceptive Neuromuscular Facilitation Association. All rights reserved.

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Purpose: The present study investigated how variations in diagonal exercises affect shoulder muscle activity, examining changes in neuromuscular activation during scapular and shoulder diagonal patterns of exercises. Furthermore, we explored whether the exercise phase affects muscle activation.
Methods: Sixteen asymptomatic male participants were recruited. Four diagonal pattern exercises (scapular anterior elevation, posterior elevation, flexion-adduction-external rotation, flexion, abduction-external rotation), and two exercise phases (concentric and eccentric) were administered. Surface electromyography data were collected.
Results: Upper trapezius activity was significantly higher during the concentric phase of scapular posterior elevation exercises compared with the others (p<0.05). The serratus anterior, anterior deltoid, and infraspinatus activities were significantly higher during shoulder diagonal pattern exercises compared with the scapular diagonal pattern exercises (p<0.05). Except for the lower trapezius, muscular activities during the concentric phase were significantly greater compared with the eccentric phase (p<0.05).
Conclusion: The current study suggests that the diagonal pattern of exercise may contribute to selective strengthening of the shoulder complex muscles and that the form of exercise should be tailored to the subject. It also suggests that diagonal exercises with concentric contractions tend to be more beneficial than eccentric contractions for overall muscle recruitment, but the effects vary for specific diagonal patterns.
Keywords: Electromyography, Exercise, Infraspinatus, PNF

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