Adaptations in pelvis, hip and knee kinematics during gait and muscle extensibility in low back pain patients: A cross-sectional study

OBJECTIVES: To compare pelvis, hip and knee kinematics during gait and extensibility of hip muscles between low back pain (LBP) and asymptomatic subjects. METHODS: Forty adult volunteers (11 men and 29 women) between 18 to 30 years from university population were included in this study. Twenty patients with LBP formed the LBP group, and 20 asymptomatic subjects formed the control group. Pelvic tilt and knee valgus, peak hip and knee joint excursion, and temporo-spatial variables were assessed during gait with Kinovea software. Extensibility of hip muscles was measured by Active Knee Extension test (AKE), modified Ober test, and Thomas test. RESULTS: There was a significant increase in pelvic tilt (p< 0.01), valgus angle (p< 0.01), and a significant decrease in hip extension (p< 0.01) in the LBP group compared to the control group. There was a significant decrease in extensibility of the hip flexors (p< 0.05) of the dominant leg and in the hip abductors (p< 0.01) in the LBP group compared to the control group. CONCLUSIONS: The findings of this study suggest that non-specific mechanic LBP patients present differences in the pelvis, hip and knee kinematics in sagittal and frontal plane during gait and less hip flexors and abductors muscles extensibility compared to asymptomatic subjects.