THE EFFECT OF HAMSTRING MUSCLE STRETCHING ON STANDING POSTURE AND ON LUMBAR AND HIP MOTIONS DURING FORWARD BENDING

Background and Purpose. The purpose of this study was to determine whe ther stretching the hamstring muscles affects extensibility,as indicat ed by straight leg raising (SLR), lumbopelvic posture, and the relativ e amounts of lumbar and hip motion during forward bending. Subjects. T hirty-nine subjects without known musculoskeletal impairments of their spine or lower extremities and with tight hamstring muscles (ie, SLR of less than or equal to 70 degrees) were randomly assigned to either a stretching group or a control group. Methods. A three-dimensional di gitizer was used to measure lumbar, pelvic, and hip positions while su bjects were in a standing position and during partial and full forward bending. Results. Straight leg raising and hip motion during late and total forward bending were increased after stretching. No changes occ urred in standing posture or lumbar motion during forward bending. Con clusion and Discussion. The results of this study suggest that there i s no relationship between hamstring muscle length and lumbopelvic post ure. There was some indication, however, that stretching the hamstring muscles may affect motion during forward bending.