Characterization of abnormal asymmetrical lifting mechanics in surgery-candidate patients with lumbar radiculopathy.

Study design/setting: Case-Control Study.

Purpose: To quantify and evaluate kinematic parameters and range of motion during asymmetric lifting in patients with symptomatic lumbar degeneration with unilateral radiculopathy (LR) on the symptomatic and asymptomatic side, and to provide insight into the compensatory mechanisms used by patients, aiming to improve diagnostic accuracy and enhance therapeutic strategies.

Methods: Thirty one LR surgical candidates and 26 healthy controls were enrolled consecutively at a single institution. Participants were fitted with a full-body external reflective marker set for three-dimensional motion capture. Participants performed six standardized functional lifting tasks using a box weighted up to 10% of their body mass, lifting to a target surface positioned 1 m high. Kinematic parameters and range of motion during asymmetrical lifting were compared between groups using linear mixed-effects regression models.

Results: Patients with LR exhibited significantly reduced bilateral hip flexion during the initiation of asymmetrical lifting tasks, irrespective of the direction of the lift. When lifting toward the symptomatic side, hip flexion was reduced on both the symptomatic (89.4° vs. 97.2°, p = 0.027) and asymptomatic (89.1° vs. 97.2°, p = 0.036) limbs compared to healthy controls. Similarly, during lifts toward the asymptomatic side, reductions were observed on both the symptomatic (87.7° vs. 97.2°, p = 0.001) and asymptomatic (88.6° vs. 97.2°, p = 0.022) sides. Additionally, LR patients had significantly reduced hip flexion in the lower extremity on the same side as the asymmetric lift (symptomatic: 66.7° vs. 80.2°, p < 0.001 and asymptomatic: 65.4° vs. 80.2°, p < 0.001). LR patients also experienced altered pelvic rotation during both the lift on the symptomatic side (45.3° vs. 50.7°, p = 0.046) and the asymptomatic side (44.9° vs. 50.7°, p = 0.028) compared to controls.

Conclusion: Patients with LR demonstrated significantly less hip and pelvis motion when lifting to both the symptomatic and asymptomatic side. This study quantitatively assessed clinically measurable kinematic parameters and range of motion during asymmetric lifting activities in patients with LR. These findings may provide further insight into disease-specific effects and compensatory mechanisms associated with symptomatic lumbar degeneration with unilateral radiculopathy.