Hamstring injuries can occur to either of the three muscles in the back of the leg. These muscles bend the knee and extend the hip so they are called a two joint muscle. They all have the same origin via a tendon at the back of the pelvis. The tendon can be felt under your sit bone. They each have separate muscle bellies and insert at different points below the knee joint. The distal tendons can be seen and felt on the medial and lateral sides of the knees. The hamstrings play an important part in sports for power activities. Hamstring injuries we see are typically either a tear in the muscle or tendon and tendinopathy. A tendinopathy involves micro-tears in the tendon fibres.
Who is affected? These injuries are common with runners performing hills and sprinting. Other risky sports are football, hockey and rowing. Also we see them in forward lean working and in yoga. Most of them can be classified as sprinting type injuries, with sudden acceleration or deceleration or stretching types with high kicks, split positions and glide tackling.
How we assess a hamstring injury
Taking a thorough history from the patient is the key to most of the diagnosis in the clinic. With a tear most people will be able to describe exactly when it happened and where they felt it. Depending on the degree of tear in the muscles fibres, there will be pain, swelling and later some bruising. A tendinopathy may be more subtle and come on slowly over time. Patient feels a soreness in the top of the hamstring tendon, under the sit bone.
There a number of clinical tests that we can do to diagnose if this is a hamstring injury or perhaps a lower back problem referring pain in to back of the leg. Contracting the muscle or stretching it will determine which muscle is injured and whether it is in the muscle area or tendon. When the pain is severe, if there is lots of bruising, or the injury occurred in the tendon origin, we may refer you for imaging tests. Only in severe cases will surgery repair be required and only when the tendon is torn. Tendinopathies which are irritated tendons, don’t need repair. The degree of injury and where it is will determine the type of rehabilitation.
Most of the good quality research points to an exercise based program. This applies to both tendon and muscle in injuries. They key to treatment is progressive loading. We start with basic isometric contractions with minimal pain response and then progress to concentric contractions with weights. There are some protocols that have shown good results with more of an eccentric based approach. This involves putting the muscle on length tension while you contract it. In our opinion a combined approach makes sense and is different for each individual. We also need to look at your biomechanics to see if you are not making efficient use of the calf, foot and hip. You may be over-using the hamstring without the help of the muscles above and below. For runners we look at your running gait to see if you are over-striding or not using your gluteal muscles correctly.
In the acute stage of the injury, there are many exercises that can be performed with just body weight and therabands. Later as pain decreases you can start using weights. Typical exercise are hip extension with pulleys, hamstring curls lying on the front. A very effective exercise is bridging, lying on your back. You can load more in the hamstrings the further away your heels are placed from the hip. You want to avoid a lot of stretching in the first two weeks as this can weaken the muscle or tendon repair. We usually use the pain scale of 3/10 to guide patients when they are doing the exercises. As we introduce more home exercises its important to have rest days so the new tissue can repair itself. The rehabilitation for both tendon and muscle injuries is quite similar. With proximal tendon injuries you want to avoid putting too much pressure on the sit-bone area when you are doing the exercises.
The classic Pilates equipment is ideal for hamstring injuries and works very well with physiotherapy. The equipment is versatile so that we can work with the acute painful injuries and progress all the way to sport specific rehabilitation. The reformer and chair have a system of progressive spring tension that allows us to modify the load and resistance. The technique is also ideal for eccentric strengthening which comes later in the recovery process. We provide supervision on the equipment at our Downtown Toronto location. All sessions are provided by registered physiotherapist, Damian Wyard.
Over-striding and lack of hip extension are common causes of hamstring injuries. When you are ready to return to running we can look at your running gait. We look at your stride and see if you need to increase your cadence and use more hip extension. Running retraining emphasizes using the calf and gluteal, so that the hamstrings don’t get over-loaded.