Correlations Between Hip Extension Range of Motion, Hip Extension Asymmetry, and Compensatory Lumbar Movement in Patients with Nonspecific Chronic Low Back Pain.

BACKGROUND This study aimed to confirm the correlations among hip extension range of motion, hip extension asymmetry, pain intensity, disability index, and compensatory lumbar movement in patients with nonspecific chronic low back pain. MATERIAL AND METHODS Of 66 patients with nonspecific chronic low back pain and limited hip extension, 59 met the inclusion criteria and were enrolled in the study. Pain intensity, Oswestry Disability Index (ODI), hip range of motion, compensatory lumbar extension, and compensatory lumbar rotation of the subjects were assessed. Pain was measured using a numeric pain rating scale (NPRS), and hip extension range of motion and compensatory lumbar movement were evaluated using a digital dual inclinometer (Dualar IQ, JTech Medical, United States). Correlation analysis was used to analyze the data. RESULTS A strong correlation was observed among hip extension asymmetry, pain intensity, and disability index (P<0.05). However, no correlation was observed among compensatory lumbar rotation and extension, pain intensity, and ODI. A strong correlation also was observed between limited hip extension range of motion and compensatory lumbar rotation (P<0.05) but not between limited hip extension range of motion and compensatory lumbar extension (P>0.05). CONCLUSIONS The results of this study showed that hip extension asymmetry might be a more critical factor than hip extension range of motion. The strong correlation between limited hip extension and compensatory lumbar rotation suggests a risk of micro-trauma due to compensatory lumbar rotation.