The hamstring is a group of 3 big muscles in the back of the thigh. Pulling a hamstring is common among athletes, especially those whose sports involve sprinting, kicking, or extreme stretching (eg. dance). “Pulling” a muscle means that the muscle or tendon has torn to some extent, and in the medical world this is called a “strain”. The severity of a tear is classified as grade I (mild), II (moderate), or III (severe, a complete rupture).
Patients often ask how long their injury will take to heal. Several factors play into this, such as the type of tissue (does it have a good blood supply to promote healing?), the severity of the initial injury, and whether or not the person is continuing activities that stress the tissue.
With a hamstring strain, the location of the injury also has prognostic value because of the type of tissue involved. Sprinting injuries usually result in a strain closer to the back of the knee, whereas kicking or stretching injuries often occur near the upper thigh. One study reported that it took about 16 weeks for patients to return to their pre-injury status after a strain near the knee. For those with an upper thigh injury, it took about 50 weeks to reach full recovery!
Hamstring strains are notorious for recurring, with 1/3 of patients sustaining a repeat injury. The highest risk is during the 1st two weeks after returning to sport and unfortunately the 2nd injury is usually more severe than the 1st. This calls into question whether standard rehab practices are adequately preparing athletes for their return, and also whether too much pressure is put on patients and clinicians to get the athlete competing again as fast as possible.
Clearly prevention is the best medicine, and I would love to tell you that to prevent a hamstring strain, all you need to do is stretch. This, however, is not supported in the literature. While maintaining good muscle length is helpful, there’s more to it.
To reduce your risk of a hamstring strain and to properly treat a strain if it does occur, you need to develop a good balance between your eccentric hamstring strength and concentric quadriceps strength. You also need to have good neuromuscular control of your core and legs. I’ll let you seek counsel from your physical therapist on how to assess and achieve these important prevention and treatment measures!
Reference
Heiderscheit BC, Sherry MA, Silder A, et al. Hamstring strain injuries: recommendations for diagnosis, rehabilitation, and injury prevention. J Orthop Sports Phys There 2010;40(2):67-81.