Hamstring injury

Also called Pulled hamstring, Torn hamstring

A common sprinting injury with a high re-injury rate. Returning too early is what causes the second one.

What it is

A strain or tear of the muscles at the back of the thigh, usually during sprinting, kicking or a sudden stretch.

It is one of the commonest sports injuries and has a notoriously high recurrence rate, largely because people return to sport before the muscle has regained its strength and length.

Injuries are graded by severity, from a minor strain to a complete tear. Most are managed without surgery.

The important distinction is a **proximal hamstring avulsion**, where the tendon pulls off the bone at the sitting bone. It typically happens with a sudden forward split-type movement, causes a pop, extensive bruising and difficulty walking, and, if the tendons are fully detached and retracted, needs surgical repair within a few weeks. Missing it produces long-term weakness and pain sitting.

Rehabilitation is not rest. Progressive loading, particularly eccentric strengthening such as the Nordic hamstring exercise, both speeds return and substantially reduces re-injury, and it is one of the best-evidenced interventions in sports medicine.

In an older person, hamstring pain without a clear injury is more likely to be referred from the back or a tendinopathy at the sitting bone.

Signs you might notice

Sudden sharp pain at the back of the thigh during sprinting or stretching.

Sometimes an audible pop.

Difficulty walking, and inability to continue activity.

Swelling and, over days, extensive bruising down the back of the thigh.

Tenderness, weakness and pain on stretching or resisting knee bending.

Assessment needed: a pop with extensive bruising near the sitting bone, difficulty walking, or a palpable gap, which may be an avulsion needing surgical opinion within weeks.

Also assess: numbness or tingling down the leg, which suggests nerve involvement; or pain that came on without an obvious injury, which may be referred from the back.

Urgent: a very swollen, tense, extremely painful thigh, which may be compartment syndrome.

How it can affect day-to-day life

The first 48 hours are about protection and gentle movement rather than complete rest; prolonged immobility weakens the muscle further.

The return-to-play decision is where injuries recur. Criteria based on strength, flexibility and pain-free function are far better than a fixed number of weeks, and rushing back is the single biggest predictor of a second injury.

For amateur athletes, access to physiotherapy is often limited, and a self-directed progressive loading programme with good instructions is genuinely effective.

Bruising appearing days later and tracking down towards the knee is normal and alarming.

For sedentary people, hamstring strains are less common; pain at the sitting bone that is worse with prolonged sitting and driving is usually a tendinopathy and is treated differently.

Preventive eccentric strengthening reduces hamstring injuries substantially in sport and is under-used at amateur level.

Supporting someone well

In the first 48 hours: protect, use ice for comfort, compress, elevate, and start gentle pain-free movement.

Do not rest completely; progressive loading is the treatment.

Ask for physiotherapy and do the eccentric strengthening programme.

Return based on strength and pain-free function, not on a date.

Get a suspected avulsion assessed quickly; surgical repair has a time window.

Warm up properly and include eccentric hamstring work as prevention, in training as well as in rehabilitation.

Get pain without an injury assessed for a back or tendon cause.

Get a tense, very swollen thigh assessed urgently.

Where to get help

A GP practice or self-referral to physiotherapy.

Urgent care or A and E for a suspected avulsion, severe swelling or inability to walk.

Sports medicine or orthopaedics for surgical opinion.

Chartered Society of Physiotherapy publish rehabilitation guidance.