Superior Gait Performance and Postural Stability among Yoga Instructors – Inertial Measurement Unit-Based Evaluation

Abstract Background Yoga movements involve a series of motions of the core and lower limb muscles that require constant body adjustments to maintain balance and proper body alignment. Inertial measurement unit, a wearable device that is consisted of 3-axis accelerometers, 3-axis gyroscopes and 3-axis magnetometers, can provide objective data for motion analysis. This study aimed to investigate gait symmetry and single-leg stance balance of professional yoga instructors versus age-matched normal controls using inertial measurement unit (IMU) - based evaluation. Methods Twenty-five yoga instructors and twenty-five healthy control subjects were recruited to conduct the walking experiments and single-leg stance tests. Kinematic data were measured by attaching IMUs to the lower limbs and trunk. The asymmetry of swing phases during gait cycles was assessed using the normal walk and tandem walk tests with eyes open and closed, respectively. The subjects subsequently conducted four single-leg stance tests, including a single-leg stance on both legs with eyes open and closed. Two balance indexes regarding the angular velocities of the waist and chest were defined to assess postural stability. Results The gait asymmetry indexes of yoga instructors were significantly lower than those of the normal controls on normal walk and open-eye tandem walk tests. The asymmetry indexes also showed a smaller value in the yoga instructors on close-eye tandem gait; however, it did not reach statistical significance. Similarly, the yoga instructors had better body balance, that is, smaller angular velocities on both the waist and chest, in all four single-leg stance tests. This indicates superior postural stability over both the waist and chest levels of yoga instructors during the single-leg stance. Conclusion The findings of this study suggest that yoga practice improves gait asymmetry and balance ability in healthy adults. However, further intervention studies are needed to confirm the effect of yoga training. Trial Registration: This study was registered with an ClinicalTrials.gov Identifier: NCT05449730.