Health Characteristics, Neuromuscular Attributes, and Mobility Among Primary Care Patients With Symptomatic Lumbar Spinal Stenosis: A Secondary Analysis
Authors: Schmidt Catherine T. , Ward Rachel E. , Suri Pradeep , Kurlinski Laura , Anderson Dennis E. , Kiely Dan K. , Bean Jonathan F. 
Published: March 2016

Background and Purpose:
Mobility problems are common among older adults. Symptomatic lumbar spinal stenosis (SLSS) is a major contributor to mobility limitations among older primary care patients. In comparison with older primary care patients with mobility problems but without SLSS, it is unclear how mobility problems differ in older primary care patients with SLSS. The purpose of this study was to compare health characteristics, neuromuscular attributes, and mobility status in a sample of older primary care patients with and without SLSS who were at risk for mobility decline. We hypothesized that patients with SLSS will manifest poorer health and greater severity of neuromuscular impairments and mobility limitations.

Methods:
This is a secondary analysis of the Boston Rehabilitative Study of the Elderly (Boston RISE). Fifty community-dwelling primary care patients aged 65 years or older at risk for mobility decline met inclusion criteria. SLSS was determined on the basis of computerized tomography (CT) scan and self-reported symptoms characteristic of neurogenic claudication. Outcome measures included health characteristics, neuromuscular attributes (trunk endurance, limb strength, limb speed, limb strength asymmetry, ankle range of motion [ROM], knee ROM, kyphosis, sensory loss), and mobility (Late-Life Function and Disability Instrument: basic and advanced lower extremity function subscales, 400-meter walk test, habitual gait speed, and Short Physical Performance Battery score). Health characteristics were collected at a baseline assessment. Neuromuscular attributes and mobility status were measured at the annual visit closest to conducting the CT scan.

Results and Discussion:
Five participants met criteria for having SLSS. Differences are reported in medians and interquartile ranges. Participants with SLSS reported more global pain, a greater number of comorbid conditions [SLSS: 7.0 (2.0) vs no-SLSS: 4.0 (2.0), P < .001], and experienced greater limitation in knee ROM [SLSS: 115.0° (8.0°) vs no-SLSS: 126.0° (10.0°), P = .04] and advanced lower extremity function than those without SLSS.
A limitation of this study was its small sample size and therefore inability to detect potential differences across additional measures of neuromuscular attributes and mobility. Despite the limitation, the differences in mobility for participants with SLSS may support physical therapists in designing interventions for older adults with SLSS. Participants with SLSS manifested greater mobility limitations that exceeded meaningful thresholds across all performance-based and self-reported measures. In addition, our study identified that differences in mobility extended beyond not just walking capacity but also across a variety of tasks that make up mobility for those with and without SLSS.

Conclusion:
Among older primary care patients who are at risk for mobility decline, patients with SLSS had greater pain, higher levels of comorbidity, greater limitation in knee ROM, and greater limitations in mobility that surpassed meaningful thresholds. These findings can be useful when prioritizing interventions that target mobility for patients with SLSS.