This study aims to identify the effects of extracorporeal shock wave therapy and stretching technique on flexibility, muscle tone and pressure pain threshold of a shortened hamstring. A total of 40 patients with hamstring shortening was randomly assigned to either the extracorporeal shock wave therapy group (n=20) or extracorporeal shock wave therapy with stretching technique group (n=20) to identify the effects of the two different forms of physical therapy intervention. All the participants underwent extracorporeal shockwave therapy twice a week for 3 weeks, and the extracorporeal shockwave therapy with stretching technique group performed stretching techniques with the same frequency for 3 weeks. To measure hamstring flexibility before and after intervention, the passive straight leg raising test was performed, and muscle tone and pressure pain threshold were assessed. The flexibility of the hamstrings significantly improved, while the pressure pain threshold increased in both groups. These findings suggest that the effective in improving hamstring flexibility, reducing muscle tone, and increasing pressure pain threshold in adults with hamstring shortening.