PNF and Movement 2021; 19(2): 153-162
Comparison of Changes in Dynamic Balance and Leg Muscle Activity in Adults in Their 20s With or Without Shoes
Su-Hong Ahn, P.T., Ph.D.⋅Su-Kyong Lee, P.T., Ph.D.1†⋅Ju-Hui Yang, P.T., M.S.⋅ Jae-Sung Jo, P.T., B.S.2⋅Jin-Sung Park, P.T., Ph.D.3
Department of Biomedical Health Science, Graduate School, Dong-Eui University
1Department of Physical Therapy, College of Nersing and Healthcare Sciences, Dong-Eui University
2Department of Physical Therapy, Walk Rehabilitation Hospital
3Daonwellness Corp.
Correspondence to: Su -Kyong Lee (
Received: March 18, 2021; Revised: April 20, 2021; Accepted: April 27, 2021; Published online: August 31, 2021.
© Korea Proprioceptive Neuromuscular Facilitation Association. All rights reserved.

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.
Purpose: The purpose of this study was to investigate the difference in the dynamic balance and leg muscle activity of adults in their 20s with or without shoes.
Methods: In this study, seven male and 11 female university students in their 20s were randomized to determine the order of being with or without shoes, and the dominant foot was supported on the central platform of dynamic balance according to the order procedure. Using the opposite foot, the distance of leg stretching in the anterior, posterior medial, and posterior lateral directions and the muscle activity of the supporting leg were measured. Muscle activity measurement sites were attached to the dominant vastus medialis oblique muscle, vastus lateral oblique muscle, tibialis anterior muscle, peroneus longus muscle, and lateral gastrocnemius muscle.
Results: As a result of this study, the distance of leg stretching was significantly increased in the anterior, posterior medial, and posterior lateral directions when barefoot rather than when wearing shoes (p < 0.05). The muscle activity of the vastus medial and lateral oblique muscles was significantly increased in all three directions when barefoot rather than when wearing shoes (p < 0.05). The muscle activity of the tibialis anterior was significantly increased in the anterior direction when barefoot (p < 0.05), the peroneus longus muscle was significantly increased when it was barefoot in the posterior medial direction (p < 0.05), and the lateral gastrocnemius muscle activity significantly increased when barefoot in the posterior direction (p < 0.05).
Conclusion: The movement of the legs is freed when barefoot as compared to when wearing shoes, and being barefoot can effectively activate muscle activity and improve balance ability.
Keywords: Dynamic balance test, Muscle activity, Shoes, Foot reach length

This Article