Relationship between ambulation and obesity in older persons with and without low back pain.

CONTEXT: For obese older persons, ambulation is both functionally important and a means of weight control. The relationship between weight and ambulation is not known in this population. Also, the extent to which pain interferes with ambulation is not studied.
OBJECTIVE: To examine the relationship between obesity and ambulation, and to determine the effect of pain and body mass index (BMI) on ambulation in older persons. DESIGN, SETTING, AND PARTICIPANTS: Retrospective study of 82 older persons, ages 55-79 y, some with no back pain recruited from the community, others with back pain or spinal stenosis recruited from a magnetic resonance imaging (MRI) scanner as part of a larger university study of spinal stenosis. OUTCOME MEASURES: Age, Visual Analog Scales for pain, BMI, patient diagnosis (no pain, mechanical back pain, and spinal stenosis), walking velocity and stride length on a 15-min laboratory ambulation test, and 1-week community ambulation measured with a pedometer (steps, distance, and energy expenditure).
RESULTS: BMI had a significant inverse relationship with ambulatory measurements in terms of the distance walked, steps taken, and walking velocity. Pain severity and pain category also had a significant inverse relationship with these measures. A negative correlation was observed between pain and obesity, although the relationship was statistically nonsignificant. DISCUSSION: Obese older people walked less than the nonobese older people. Pain was associated with decreased ambulation. Clinicians who intend to encourage increased ambulation in older obese persons should consider possible barriers posed by musculoskeletal pain.