pISSN 2288-6982
eISSN 2288-7105



Original Article

Phys. Ther. Korea 2021; 28(3): 208-214

Published online August 20, 2021

© Korean Research Society of Physical Therapy

Relationship Between the Closed Kinetic Chain Upper Extremity Stability Test and Strength of Serratus Anterior and Triceps Brachii Muscles

Young-soo Weon1,2 , BPT, PT, Sun-hee Ahn2,3 , PhD, PT, Jun-hee Kim2,3 , PhD, PT, Gyeong-tae Gwak1,2 , BPT, PT, Oh-yun Kwon2,3 , PhD, PT

1Department of Physical Therapy, The Graduate School, Yonsei University, 2Kinetic Ergocise Based on Movement Analysis Laboratory, 3Department of Physical Therapy, College of Health Science, Yonsei University, Wonju, Korea

Correspondence to: Oh-yun Kwon

Received: July 5, 2021; Revised: July 13, 2021; Accepted: July 16, 2021

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background: The CKCUES test evaluates the functional performance of the shoulder joint. The CKCUES test scores CKC exercises of the upper limbs to examine shoulder stability. Although the CKCUES test provides quantitative data on functional ability and performance, no study has determined the relationship between CKCUES scores and SA and TB muscle strength.
Objects: The objective of this study is to determine the relationship between the CKCUES test scores and the strength of the SA and TB muscles in the CKCUES and unilateral CKCUES tests.
Methods: Sixty-six healthy male volunteers participated in the study. A Smart KEMA strength sensor measured SA and TB muscle strength. Two parallel lines on the floor indicated the initial hand placement to start CKCUES tests. For 15 seconds, the subject raises one hand and reaches over to touch the supporting hand, then returns to the starting position.
Results: The correlation between the CKCUES test scores and the strength of the SA was strong (r = 0.650, p < 0.001), and the TB was moderate (r = 0.438, p < 0.001). The correlation between the unilateral CKCUES test and the strength of the SA of the supporting side was strong (r = 0.605, p < 0.001), and swing side was strong (r = 0.681, p < 0.001). The cor-relation between the unilateral CKCUES test and the strength of the TB of the supporting side was moderate (r = 0.409, p < 0.001), and swing side was moderate (r = 0.482, p < 0.001).
Conclusion: Our study showed that the CKCUES test had a strong association with isometric strength of SA and moderate association with that of TB. These findings suggest that the CKCUES test can evaluate the function of the SA. Moreover, the unilateral CKCUES test can evaluate unilateral shoulder function.

Keywords: Muscle strength, Physical functional performance, Shoulder joint