Which Neuromuscular Attributes Are Associated With Changes in Mobility Among Community-Dwelling Older Adults With Symptomatic Lumbar Spinal Stenosis?

Objectives: To identify neuromuscular attributes associated with mobility and changes in mobility over 2 years of follow-up among patients with and without symptomatic lumbar spinal stenosis (SLSS).

Design: Secondary analysis of a longitudinal cohort study.

Setting: Outpatient rehabilitation center.

Participants: Community-dwelling older adults ≥65 years with self-reported mobility limitations (N=430). SLSS was determined using self-reported symptoms of neurogenic claudication and imaging-detected lumbar spinal stenosis.

Interventions: Not applicable.

Main Outcome Measure: Basic and advanced mobility as measured by the Late-Life Function and Disability Instrument (LLFDI).

Results: Among 430 community-dwelling older adults, 54 (13%) patients met criteria for SLSS, while 246 (57%) did not. On average LLFDI basic and advanced mobility scores decreased significantly from baseline through year 2 for participants with SLSS (basic: P=.04, 95% CI 0.18, 5.21; advanced P=.03, 95% CI 0.39, 7.84). Trunk extensor muscle endurance (trunk endurance) and leg strength were associated with baseline basic mobility (R=0.27, P<.001) while leg strength and knee flexion range of motion (ROM) were associated with baseline advanced mobility among participants with SLSS (R=0.47, P<.001). Among participants without SLSS trunk endurance, leg strength and ankle ROM were associated with baseline basic mobility (R=0.38, P<.001), while trunk endurance, leg strength, leg strength asymmetry, and knee flexion ROM were associated with advanced mobility (R=0.20, P<.001). Trunk endurance and leg strength were associated with change in basic mobility (R=0.29, P<.001), while trunk endurance and knee flexion ROM were associated with change in advanced mobility (R=0.42, P<.001) among participants with SLSS. Among participants without SLSS trunk endurance, leg strength, knee flexion ROM, and ankle ROM were associated with change in basic mobility (R=0.22, P<.001), while trunk endurance, leg strength, and knee flexion ROM were associated with change in advanced mobility (R=0.36, P<.001).

Conclusions: Patients with SLSS experience greater impairment in the neuromuscular attributes: trunk endurance, leg strength, leg strength asymmetry, knee flexion and extension ROM, and ankle ROM compared to patients without SLSS. Differences exist in the neuromuscular attributes associated with mobility at baseline and decline in mobility over 2 years of follow-up for patients with and without SLSS. These findings may help guide rehabilitative care approaches for patients with SLSS.