The hamstrings are a large group of muscles found at the back of the thigh. The primary role of these muscles is to bend the knee and collectively, these muscles are some of the strongest in the body. Despite their strength, the hamstrings are very prone to injury especially when overworked or undertrained. Hamstring strains and tears are quite common in sports that involve sprinting, jumping and sudden changes in speed. Rugby, touch and soccer players are some of the athletes most commonly affected by hamstring tears.
Grade 1 (mild) – A few muscle fibers are either damaged or ruptured; there may be pain a day after the injury but no loss of movement.
Grade 2 (moderate) – Roughly half of the muscle fibers are torn; there may be acute pain and mild loss of function; walking may be affected. You may notice some bruising in the hamstring or back of the knee.
Grade 3 (severe) – More than half of the muscle fibers are ruptured and there is immense pain and swelling; definite muscle weakness and loss of function. There will be bruising in the hamstring, back of the knee and sometimes into your calf muscle.
The symptoms of a hamstring tear depend on the severity of the injury. Common symptoms include pain at the back of the thigh – which could range from mild to severe, swelling, bruising, loss of knee motion, tenderness at the back of the thigh, reduced length and muscle weakness of the hamstring. In some cases, tingling, numbness and weakness of the structures below the knee are seen. However, these are rare.
There are also recognized risk factors, that increase the possibility of hamstring tears. These include increased age, fatigue, strength imbalance, previous injury of the hamstrings, poor core stability, poor hamstrings flexibility and tight hip flexors. Of these risk factors, previous hamstring injury is the biggest.
A single cause of hamstring tears can be difficult to determine. However, it is thought that a lack of coordination between the hamstrings and quadriceps muscles during sudden changes of speed or kicking can cause the hamstrings to contract excessively or become overstretched, causing a tear. Apart from having already suffered a previous hamstring injury, one of the biggest causes we see in the clinic is people who have been hibernating for the winter months. They come out and play touch or summer football, with no build up to the levels that are needed to play these sports. They may have got through their first game unscathed but then increase the intensity of their running or play and “ping” there goes the hammy with bending over to scoop up the ball, sprinting for that gap to the try line or channeling their inner Messi for that winning goal.
The most common question we hear in the clinic is “So, when can I get back into sport?” This is a difficult question to answer as everyone is different and their injuries present differently. As a general rule, the lesser the severity the quicker you will be able to get back into your sport. For example, a grade 1 tear may take between 2-4 weeks whereas a grade 3 tear can be between 8-12 weeks. The biggest thing for hamstring injuries is not rush back into your sport without properly loading the tissue first, otherwise you increase your risk of re-injury.
Initial treatment of a hamstring tear is to reduce your pain, swelling and bruising, improve your flexibility and then strength. Common treatments that are used in physiotherapy to treat hamstring tears include: electrotherapy, ice, heat, massage, stretches of both the muscle and nerves and strengthening exercises of the core, gluteals and hamstrings. Research has shown that there are no detrimental effects and have improved recovery times with the integration of a gentle stretching program started 2 days after you have sustained an injury. Gentle strengthening exercises can also be started relatively early to help reduce your pain and maintain the function of the muscle in those early stages post injury. Once you are ready to return to your usual hobby or activity, a maintenance program is usually needed to help reduce your risk of re-injury.
Trying to prevent hamstring tears is important business. Current research shows that exercises that incorporate a lengthening/eccentric component are superior to ones that don’t include this. However, guidance from one of our highly trained physiotherapists will show you which exercises to start with and then gradually progress you through to these eccentric or lengthening exercises to reduce the risk of you re-injuring that hamstring you have done so well at rehabbing.