Hamstring strains are a common injury sustained in sporting events. Sprinting activities, such as football, rugby, and track are notorious for causing hamstring injuries, but also dancers are susceptible secondary to the extreme stretching demands imparted on the same muscles. In the NFL, one study showed incidence of hamstring strains to be secondary only to knee injuries, with the time-loss from sport depending on severity and location of the injury. The main problem with hamstring injuries is the high recurrence rate, with one-third of the patients sustaining another injury with the most common time-frame being within the first two weeks after initial onset. Because of this high recurrence rate, it is imperative to properly diagnose, and treat, hamstring injuries to prevent further issues and allow the athlete to safely return back to full function.
The hamstrings muscle consists of three different muscles, all which attach below the knee. They all originate on the ischial tuberosity, which is known as the sits-bone (the bone on each buttocks which we sit on when sitting up tall). Two of the three muscles (semimembranosus and semitendinosus muscles) travel down the back of the thigh to attach below the knee on medial side, while the third tendon (biceps femoris) attaches below the knee on the outside. Their functions are to assist in hip extension and knee flexion. They can get injured within the muscle belly, commonly at the junction between the muscle and the tendon, where the tendon attaches onto the bone distally, or less commonly at the origin of the muscle at the buttocks (proximal hamstring tear). The severity of the injury can be graded on a scale from 1-3. A grade I strain is a mild strain, whereas a grade III strain is a full muscle tear or rupture. Hamstring strains are identified as being painful to full stretch, painful to resist when the muscle is contracted, and painful to palpate at the site of injury. Research has correlated the extent of injury to the amount of pain and weakness to muscle contraction and to the extent of pain and limited motion to muscle stretch, when the injury is to the muscle belly or distal tendon. Proximal hamstring tears are less predictable, and tend to take a significant longer time to improve than the more distal injuries.
Treatment for a hamstring strain consists of working to improve the scar which forms to the hamstring muscle from the injury, by regaining normal flexibility and strength to the hamstrings and progress back to functional activities. Physical therapy has been shown to be beneficial to assist in getting athletes safely back to sport from hamstring injuries. Initially, activity modification is warranted if they worsen the symptoms, to assist in controlling the pain and inflammation. Rest, frequent icing, and controlled weight-bearing can help with the acute phase, and get the patient’s pain under control. After the first few days, weight-bearing as tolerated is progressed, but fast walking and longer strides may worsen the symptoms, and normal walking may only occur with some assistance, warranting the possible use of a crutch or walking stick. The physical therapist helps teach normal walking and appropriate activities during this time, and begins the patient on appropriate stretching and strengthening exercises. Progressive eccentric strengthening of the hamstring muscles consists of slow-controlled lengthening of the hamstring muscles under load, which forces higher amounts of muscle contraction than concentric contractions. For example, a concentric hamstring contraction is a hamstring curl (where you bring your heel up towards your buttock as your knee flexes), and the eccentric motion is the controlled lowering of the heel back down to the ground. The therapist understands how to progressively load the hamstring muscles, and functionally re-train athletes back to their sport in a structured and timely fashion. Manual therapy to the site of injury, through cross-friction mobilization, is also beneficial and may be used to help with normalizing the injured tissue in the sub-acute phase of healing. A grade II hamstring strain typically takes 12 weeks to fully heal (when treated appropriately), though the athlete may likely return to sport before that time if he meets all the requirements for strength, flexibility, and functional testing. To note, however, is that the muscle may still have healing occurring after the athlete returns to sport, and continual strengthening and functional exercises will still be appropriate during this time.
At Life’s Work Physical Therapy (LWPT), our physical therapists are experts in differential diagnosis for lower extremity injuries. We pride ourselves not only in the ability to properly diagnose hamstring injuries, but to also identify possible reasons why the hamstring injury occurred in the first-place. Commonly, issues identified above or below the hamstrings, somewhere else along the kinetic chain, can lead an athlete susceptible to a hamstring injury. The physical therapist individualizes each patient’s treatment plan to combat these other issues, which will help with long-term success by improving an athlete’s performance and safely returning that athlete back to his/her sport. If you have experienced a hamstring injury, or are having difficulty getting back to full function after a hamstring injury, contact LWPT today for an evaluation with one of our skilled therapists today, and get on the right path to recovery today.