What is it?
The hamstrings are a group of muscles located on the back of the thigh. The hamstring is not one single muscle, instead a collection of 3 different muscles. The hamstring predominantly originates from your sitting bone and attaches just below the back of your knee. The primary role of the hamstrings is to bend the knee as well as extending the hips. The hamstrings are very prone to injury, increasingly so if you have sustained a strain previously. Often the hamstrings are strained during sporting activity, such as sprinting, jumping and sudden changes in speed. Whilst it is common in the younger sporting population, any age group can experience this injury.
Grades of hamstring strain
Grade 1 (mild) â€“ Minor strain of a few muscle fibers. Pain may not be experienced immediately and there will be minimal loss in power or flexibility. However, there will be pain/tightness during certain activities such as walking up hill, acceleration/deceleration and jumping.
Grade 2 (moderate) â€“ Partial tear in the muscle. There will be acute pain, reduced flexibility, loss of power and function. There may be pain during walking and there will be difficulty straightening the knee.
Grade 3 (severe) â€“ Severe or complete rupture of the muscle fibers. There will significant and immediate pain, followed by swelling and bruising. Definite loss of function (difficulty walking), pain on palpation and surgical repair may be required.
What are the symptoms?
As discussed above, the symptoms vary significantly depending on the severity of your injury. Commonly there will be pain in the back of the thigh or knee, loss of knee motion and reduced power of the muscle.
What are the causes?
There is no single cause for a hamstring strain; depending on your biomechanics there may be a number of reasons why youâ€™ve strained your hamstring. The main cause is a lack of co-ordination between the hamstring and quadriceps during functional activities. However, there are recognised risk factors that increased the probability of hamstring tears.
Â· Previous hamstring injury
Â· Increasing age
Â· Strength imbalance between quadriceps and hamstring
Â· Poor pelvic motor control
How can they be prevented?
Majority of the above risk factors can be addressed through a targeted rehabilitation and ongoing injury prevention program. This is where your physiotherapist can help. After diagnosing the injury and severity a proposed management plan.