Hamstring muscle injuries are among the most common injuries in athletes. Outcomes are often unfavorable. Platelets are part of the patient's own blood. Injecting platelets into orthopedic injuries has been thought to induce healing, but results have been unknown for hamstring injuries. In this study, platelets were gained after a regular blood draw and were then injected back into the hamstring muscle injury. This is called a Platelet Rich Plasma (PRP) injection, which is performed with a small needle that is guided into the hamstring muscle tear using Ultrasound visualization. Blood pockets that had formed in the hamstring muscle during the initial sports injury also are drained. In this study, researchers included 55 athletes with partial hamstring muscle tears. They found that athletes treated with this new approach were able to return to play faster and had a lower reinjury rate compared to athletes treated with physical rehabilitation.