Effect of leg length discrepancy on spinopelvic alignment and mobility in healthy volunteers using a shoe lift.

Background: Leg length discrepancy (LLD) is a musculoskeletal condition in which leg length is asymmetric. LLD can adversely affect adjacent joints. A typical example is hip-spine syndrome. We aimed to investigate how LLD affects spinopelvic alignment and mobility, under conditions simulating LLD.

Methods: Fifty healthy adults (31 women, 19 men ; mean age 37.1 ± 8.9 years) participated in this study. A shoe lift was applied under the left foot to simulate LLD of 1, 2, 3, and 4 cm. Spinopelvic alignment while standing upright and mobility in flexion, extension, and lateral bending were measured under conditions simulating LLD using a Spinal Mouse device.

Results: Lumbar spine curvature in the frontal plane was significantly increased to the left as LLD increased. Sacral inclination angle in the frontal plane was significantly increased to the right by adding a lift. There was no significant difference in curvature of the thoracic spine in any parameters. Mobility of the lumbar spine during left lateral bending decreased as LLD increased. Inclination between T1 and S1 in the frontal plane when bending to the left decreased with increasing LLD.

Conclusion: Simulating LLD affects spinopelvic alignment and mobility in the frontal plane, but not significantly in sagittal plane. J. Med. Invest. 72 : 26-33, February, 2025.