Preserved Gait Symmetry Despite Attenuated Upper-Body Motion: A Within-Subject Observational Study

R. Yousefian Molla, H. Sadeghi, A. Rahnama

Abstract: Objective: Gait symmetry is a key indicator of neuromuscular integrity and movement quality. While the role of the lower limbs in maintaining symmetrical walking is well established, the contribution of the upper body—particularly natural arm swing—remains less understood, especially in trained female athletes. This study investigated whether restricting upper-limb motion affects spatiotemporal gait symmetry in professional female bodybuilders. Materials and methods: Thirty female athletes (20–34 years) completed two randomized walking conditions: normal arm swing and restricted arm swing, with upper limbs secured across the chest. Three-dimensional gait kinematics were recorded using a Vicon motion capture system. Spatiotemporal parameters and multiple symmetry indices—including Symmetry Ratio (SR), Symmetry Index (SI_avg, SI_left, SI_right), Symmetry Angle (SA), and Gait Asymmetry (GA)—were computed from bilateral temporal parameters. Paired t-tests with Bonferroni correction assessed differences between conditions. Results: Across all gait parameters—step length, step duration, stance phase, single support, and double support—no significant differences were detected between normal and restricted arm-swing conditions (all p > 0.05). Symmetry indices remained stable and close to ideal symmetrical values. These results indicate that participants effectively preserved both spatial and temporal gait symmetry despite reduced upper-body mobility. Discussion: Trained female athletes maintain robust gait symmetry even under acute upper-limb motion restriction, likely due to efficient multi-segmental compensatory mechanisms involving trunk and lower-limb coordination. Conclusion: These findings highlight the neuromuscular system's adaptability in highly trained individuals and support rehabilitation or training protocols that involve temporary upper-limb constraints.

Series on Biomechanics, Vol.40, No. 2 (2026),85-93
DOI: 10.7546/SB.40.02.08.2026

Keywords: arm movement; athletes; biomechanical phenomena; Gait; gait symmetry

DOI: 10.7546/SB.40.02.08.2026

Date published: 2026-07-17