Clinical and biomechanical biomarkers of altered functional transitions in lumbar spinal stenosis with neurogenic claudication.

Abstract

BACKGROUND: Lumbar spinal stenosis with neurogenic claudication (LSNC) affects nearly one-third of older adults and is characterized by lower extremity pain, weakness, cramping, and paresthesias, leading to functional decline and diminished quality of life. Although the impact of LSNC is well documented, compensatory movement patterns during functional transitions have not been systematically studied. PURPOSE: To identify clinical and biomechanical biomarkers of altered functional transitions in patients with LSNC using motion capture and patient-reported outcomes. STUDY DESIGN/SETTING: Retrospective, single-center, concurrent cohort study. METHODS: Thirty-seven patients with LSNC (ages 45-68) and 14 age-matched healthy controls performed three sit-to-stand (StS) trials without arm assistance. Three-dimensional motion capture quantified joint kinematics, while patient-reported outcomes were assessed using the Oswestry Disability Index (ODI) and relevant Patient-Reported Outcomes Measurement Information System (PROMIS) domains. Group differences were analyzed using linear mixed-effects models. RESULTS: The LSNC cohort demonstrated greater disability (ODI 41.3) and higher PROMIS Pain Interference (65.3) relative to controls. StS completion time was significantly prolonged (1.4s vs. 0.9s, p = 0.011). Kinematic analysis revealed reduced hip flexion (left: 55.9° vs. 66.7°, p < 0.005; right: 54.3° vs. 66.1°, p < 0.005) and decreased knee flexion bilaterally (p < 0.05). Conversely, hip rotation was increased bilaterally (p < 0.05), and left hip adduction was greater (10.2° vs. 6.7°, p = 0.002). These findings suggest compensatory strategies that reduce sagittal plane motion but increase rotational demand on the lumbar spine. CONCLUSIONS: LSNC patients demonstrate measurable alterations in lower extremity biomechanics during functional transitions, reflecting compensatory adaptations to neurogenic claudication. Motion capture derived biomarkers may support early identification of instability, enabling targeted rehabilitation strategies or expedited surgical referral.