Effect of Hamstring Eccentric Exercise on Pain and Functional Activity in Patients with Chronic Low Back Pain

Objective: This study aimed to investigate the effects of hamstring eccentric exercises on pain and functional activity in patients with chronic low back pain. Design: Randomized controlled trial. Methods: The study included 27 participants with low back pain that persisted for 3 months. The participants were randomly assigned to either the experimental group (n = 13) that performed gastrocnemius, iliopsoas, and quadratus lumborum stretching along with hamstring eccentric exercises or the control group (n = 14) that only engaged in stretching and hamstring stretching. The Nordic curl exercise was used as the eccentric exercise for the hamstrings. Each group practiced for 1 hour a day, 3 times a week, for 4 weeks. Subsequently, pain, disability index, balance, and hamstring length were measured. Results: After comparing the measurements before and after exercise, we observed significant differences in back pain, back disability index, and hamstring length within each group (p 0.05). The balance ability of the experimental group was ＜ significantly different before and after exercise (p < 0.05), whereas that of the control group did not significantly differ. There were no significant differences in back pain or hamstring length between the groups. Changes in the back disability index and balance ability were significantly greater in the experimental group than in the control group (p < 0.05). Conclusion: Hamstring eccentric exercise using Nordic curls has a positive effect on back pain, back disability index, balance ability, and hamstring length.