Influence of Hamstring Tightness in Pelvic, Lumbar and Trunk Range of Motion in Low Back Pain and Asymptomatic Volunteers during Forward Bending

STUDY DESIGN: Cross-sectional study. PURPOSE: To verify the association of hamstring tightness and range of motion in anterior pelvic tilt (PT), lumbar motion (LM), and trunk flexion (TF) during forward bending. OVERVIEW OF LITERATURE: Increased hamstring stiffness could be a possible contributing factor to low back injuries. Clinical observations have suggested that hamstring tightness influences lumbar pelvic rhythm. Movement restrictions or postural asymmetry likely lead to compensatory movement patterns of the lumbar spine, and subsequently to increased stress on the spinal soft tissues and an increased risk of low back pain (LBP). METHODS: Hamstring muscle tightness was measured using the self-monitored active knee extension (AKE) test. A bubble inclinometer was used to determine the range of motion of PT, LM, and TF during forward bending. Statistical analysis included descriptive statistics, comparisons between groups and a correlation between hamstring tightness (AKE) and anterior PT, TF, and regional LM with p≤0.05. RESULTS: The LBP group was composed of 36 participants, and the asymptomatic group consisted of 32 participants. The mean for PT in the control group was 66.7°, 64.5° for LM and 104.6° for TF. Respective values in the symptomatic group were 57.0°, 79.8°, and 82.2°. CONCLUSIONS: Participants with LBP showed restriction in the pelvis and TF range of motion, but had higher amplitudes in the lumbar spine during forward bending.