Predictors of walking performance and walking capacity in people with lumbar spinal stenosis, low back pain, and asymptomatic controls.

OBJECTIVE: To examine predictors of community walking performance and walking capacity in people with lumbar spinal stenosis (LSS), compared with people with low back pain and asymptomatic control subjects.

DESIGN: Retrospective analysis.

SETTING: University spine program.

PARTICIPANTS: Participants (N=126; 50 LSS, 44 low back pain, 32 asymptomatic control subjects) aged 55 to 80 years were studied.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Seven-day community walking distance measured by pedometer (walking performance) and a 15-minute walking test (walking capacity). All participants had lumbosacral magnetic resonance imaging, electrodiagnostic testing, and a history and physical examination, including a history of pain and neurologic symptoms, a straight leg raise test, and tests for directional symptoms, reflexes, strength, and nerve tension signs. The study questionnaire included demographic information, a history of back/leg pain, and questions about walking, exercise frequency, and pain level, as well as the standardized Quebec Back Pain Disability Scale.

RESULTS: Body mass index (BMI), pain, age, and female sex predicted walking performance (r(2)=.41) and walking capacity (r(2)=.41). The diagnosis of LSS itself had no clear relationship with either walking variable. Compared with the asymptomatic group, LSS participants had significantly lower values for all walking parameters, with the exception of stride length, while there was no significant difference between the LSS and low back pain groups.

CONCLUSIONS: BMI, pain, female sex, and age predict walking performance and capacity in people with LSS, those with low back pain, and asymptomatic control subjects. While pain was the strongest predictor of walking capacity, BMI was the strongest predictor of walking performance. Average pain, rather than leg pain, was predictive of walking performance and capacity. Obesity and pain are modifiable predictors of walking deficits that could be targets for future intervention studies aimed at increasing walking performance and capacity in both the low back pain and LSS populations.