Background: Limitations in hip flexion caused by tight hamstrings lead to excessive lumbar flexion and low back pain. Accordingly, many studies have examined how to stretch the hamstring muscle. However, no study has focused on the effect of hamstring eccentric exercise for tight hamstrings on trunk forward bending. Objects: We compared the short-term effect of hamstring eccentric exercise (HEE) and hamstring static stretching (HSS) on trunk forward bending in individuals with tight hamstrings. Methods: Thirty individuals with tight hamstrings participated in the study. The subjects were randomly allocated to either a HEE or HSS group. To determine whether the hamstrings were tight, the active knee extension (AKE) test was performed, and the degree of hip flexion was measured. To assess trunk forward bending, subjects performed the fingertip to floor (FTF) and modified modified Schober tests, and the degree of trunk forward bending was measured using an inclinometer. We used paired t-tests to compare the values before and after exercise in each group and independent t-tests to compare the two groups on various measures Results: The FTF test results were improved significantly after the exercise in both groups, and AKE for both legs increased significantly in both groups. There was no significant difference in the hip angles, mmS test results, or degree of trunk forward bending between groups after the exercise. No test results differed significantly between the two groups at baseline or after the exercise. Both groups increased hamstring flexibility and trunk forward bending. Conclusion: HSS and the HEE groups increased hamstring flexibility and trunk forward bending. However, HEE has additional benefits, such as injury prevention and muscle strengthening.

This study examined the effects of hold-relax with agonist contraction (HR-AC) on the symptoms of delayed onset muscle soreness (DOMS) induced by intensive eccentric exercise of the non-dominant biceps brachii. Ten men (mean age=26.7 yrs, mean height=172.1 cm, mean weight=66.2 kg) and ten women (mean age=27.4 yrs, mean height=165.9 cm, mean weight=60.7 kg) who had not participated in a regular exercise program for the upper extremities in the previous six months were randomly assigned to one of two experimental groups: the HR-AC group, or the control group. We measured joint range of motion (ROM), maximal voluntary isometric contraction (MVIC), and muscle soreness before eccentric exercise, and 24, 48, and 72 hours after eccentric exercise. The subjects in the HR-AC group received the HR-AC technique in the non-dominant biceps brachii. The HR-AC technique was applied 24 and 48 hours after eccentric exercise. There was no significant difference between the HR-AC and the control group. However, the HR-AC group, compared to the control group, had a significant difference between the time points of the various parameters. Increased ROM (p<.05), decreased muscle soreness (p<.05), and reduced MVIC (p<.05) were found in the HR-AC group after 72 hours. Decreased ROM (p<.05) and MVIC (p<.05), and increased muscle soreness (p<.05) were observed in the control group. These findings suggest that the HR-AC technique effectively reduces muscle soreness and increases ROM 72 hours after eccentric exercise.

Eccentric muscle contraction is more effective than concentric and iosmetric muscle contraction in increasing muscle strength. Also, eccentric or concentric-eccentric training has greater effective in neural activation and muscle hypertrophy than concentric training. In some study, eccentric exercises have been shown to reduce pain and improve function on Achilles tendinopathy. The purpose of this study was to evaluate the effect of eccentric isokinetic exercise in a patient with dislocation of the tarsometatarsal joint by traffic accident. After eccentric isokinetic training, peak torque, average work, and average power were increased. Also, the patient was fully weightbearing with a pain free normal gait thus making good recovery.