Hamstring injuries are very common in a variety of sports requiring repeated acceleration, deceleration, sprinting, or in kicking activities. Hamstring injuries account for a significant percentage of injuries per season among athletes in many different sports. This rate of injury is highlighted by the amount of competitive action or training time missed by players. A particular frustration with hamstring strain is the high recurrence rate, which is often associated with even longer absences from competition. In fact, even after returning to competitive action, athletes remain at a...