Lumbar-hip flexion motion. A comparative study between asymptomatic and chronic low back pain in 18- to 36-year-old men.

STUDY DESIGN: The amount of lumbar and hip flexion and the relative contribution within movement during standing forward bending was recorded on a group of asymptomatic men and a group of men with a history of chronic low back pain.

OBJECTIVES: To compare the relative contribution of the hip and lumbar spine to forward bending in the two groups.

SUMMARY OF BACKGROUND DATA: The hips and lumbar spine both contribute to the forward bending motion, and an aberrant pattern of contribution in one or both regions could be related to the presence of chronic low back pain.

METHODS: Thirty-two white men aged 18-36 years (15 with chronic low back pain and 17 asymptomatic) were assessed using a three-dimensional motion analysis system that allowed uninterrupted forward bending.

RESULTS: The men with chronic low back pain demonstrated a significant reduction in the mean total range and mean maximum lumbar flexion relative to the asymptomatic group. Mean hip flexion was not significantly different. Data analysis for 120 degrees of gross flexion revealed a subgroup of men with chronic low back pain with a significant decrease in hip flexion.

CONCLUSIONS: When assessing the relative motion of the lumbar spine and hips in standing forward flexion, there was measurable difference between asymptomatic men and a group of chronic low back pain patients. In particular, two subgroups of individuals with chronic low back pain appeared; one moved relatively similarly to the asymptomatic group, whereas the other sub-group demonstrated reduced hip mobility. These findings indicate the importance of assessing the lumbar and hip flexion motion in chronic low back pain patients to determine if a movement abnormality is present.