Effects of Wearing A Non-Elastic Lumbar Brace on Gait, Balance, and Squat Performance

Abstract

Purpose: This study aimed to investigate the immediate effects of wearing non-elastic and elastic lumbar orthoses (LSO) compared to a no-brace condition on gait, balance, and squat performance in healthy  adults.

Methods: In a randomized crossover design, eighteen healthy adults completed three conditions—non-elastic LSO, elastic LSO, and no LSO. Static balance was assessed once using a foam, eyes-closed Romberg test; dynamic balance was evaluated with the Limits of Stability (LOS) test from two trials averaged. Gait was measured on a treadmill with OptoGait at each participant’s self-selected speed after 2-min familiarization, capturing 30-s of continuous data. Squats to ~90° knee flexion were performed 5 repetitions per condition with 2-min rests between conditions, while EMG of the rectus femoris and semitendinosus was recorded during the task.

Results: No significant differences were found in gait or balance parameters across the three conditions. However, the non-elastic LSO significantly increased the mean and peak muscle activation of the Rectus Femoris compared to the elastic brace and no-brace conditions. In contrast, the elastic LSO significantly increased muscle activation variability (instability) compared to the non-elastic brace.

Conclusions: The non-elastic LSO did not show immediate benefits for low-level tasks but enhanced the recruitment of the Rectus Femoris muscle during the high-coordination squat exercise. The results of this study suggest that the non-elastic LSO induces joint moment redistribution, leading to increased quadriceps femoris muscle activity during high-load functional tasks.