| What We Treat
Hamstring Strain
Sudden grab in the back of the thigh during a sprint? Hamstring strains are the most common injury in running sports — and the most likely to happen again if rehabilitation stops too early.
Overview
What Is a Hamstring Strain?
The hamstrings run down the back of the thigh from the sitting bone to below the knee, and are loaded most heavily during the late swing phase of sprinting, when they are lengthening while contracting hard. That is when most strains occur. They are the most common injury in football, athletics and rugby, and have one of the highest re-injury rates in sport — which is almost entirely a function of how well the rehabilitation is completed.
Acute
Protect and start loading early
- Relative rest and compression for the first few days
- Weight-bear as comfortable; crutches only if walking is markedly abnormal
- Begin gentle isometric loading within the first few days — this is earlier than most people expect
- Avoid aggressive stretching, which can worsen the injury in the acute phase
Tap through the phases. The lengthened-position strengthening is the step most often skipped.
Symptoms
How It Tends to Feel
Hamstring strains usually announce themselves clearly:
A Sudden Grab
A sharp pulling sensation at the back of the thigh, usually during sprinting or a sudden lengthening.
Having to Stop
Most people stop immediately; the ability to continue running suggests a lower-grade injury.
Localised Tenderness
A specific tender point along the muscle, which helps identify which hamstring is involved.
Bruising
Often appearing over the following days and tracking down towards the knee.
Weakness on Bending the Knee
Reduced power resisting knee flexion, particularly in the lengthened position.
Pain High Near the Sitting Bone
A higher injury near the tendon origin generally carries a longer recovery.
Causes & Risk Factors
What Drives It
Hamstring injuries reflect the mismatch between the demands of high-speed running and the strength available at length.
High-Speed Running
The late swing phase of sprinting is when the hamstring is longest and most heavily loaded — the classic mechanism.
Reduced Eccentric Strength
Low eccentric hamstring strength is one of the most consistently identified modifiable risk factors.
Previous Hamstring Injury
The strongest single risk factor, largely because strength deficits frequently persist after return to sport.
Fatigue
Injuries cluster late in matches and training sessions, when neuromuscular control declines.
Rapid Increases in Sprint Volume
A sudden increase in high-speed running exposure, particularly early in a season, is a common precipitant.
How We Can Help You
Treatment & Management
Rehabilitation should start earlier and finish later than most people expect. Early loading speeds recovery; lengthened-position strengthening prevents recurrence.
What the evidence says
Nordic hamstring exercise programmes have been shown in randomised trials and meta-analyses to reduce hamstring injury rates by around half in football and other running sports. It is one of the best-evidenced injury prevention interventions in sport, and adherence is the main limiting factor.
Trials comparing early versus delayed rehabilitation after acute hamstring injury show earlier controlled loading leads to faster return to sport without an increase in re-injury, which has moved practice away from initial rest.
When to Seek Help
Red Flags — Don’t Ignore These
Hamstring strains are usually straightforward. Seek assessment if you notice:
⚠ Seek prompt medical assessment if you notice:
- A sudden pop high near the sitting bone with a palpable gap and marked weakness (possible tendon avulsion — needs prompt assessment)
- Extensive bruising with feeling faint or unwell
- Numbness or pins and needles in the leg, or symptoms travelling below the knee
- Calf swelling, warmth or redness (possible clot — seek same-day assessment)
- Inability to weight-bear at all, particularly after a fall rather than a sprint
These symptoms need same-day medical assessment. Please contact your GP or NHS 111 today, or attend A&E if they are severe or worsening quickly.
Common Questions
Frequently Asked Questions
How long until I can play again?
It varies considerably with grade and location. A minor strain may allow return in two to three weeks; injuries close to the tendon origin can take two to three months. Return should be based on strength symmetry and achieving maximal-speed running, not on the calendar.
Should I stretch it?
Not aggressively, and not in the first week or two. Aggressive stretching of a healing muscle can worsen the injury. Gentle range work is fine; progressive strengthening through lengthened positions is what actually restores the muscle’s tolerance to length.
What are Nordic curls?
A kneeling exercise where a partner or anchor holds your ankles and you lower your torso towards the floor as slowly as you can. It loads the hamstring eccentrically at length, and it has the strongest evidence of any single exercise for preventing hamstring injuries.
Why do hamstring injuries keep recurring?
Because most people return to sport with a persistent eccentric strength deficit and without having reached maximal-speed running. Re-injury risk is highest in the first two weeks back. Completing the programme properly is genuinely the difference.
Rehabilitate It Properly the First Time
Early loading, lengthened-position strengthening, and a return based on objective testing — because hamstrings punish shortcuts.
Book Your Initial AssessmentThis page is for general information only and isn’t a substitute for individual medical advice. If you’re experiencing any of the warning signs above, contact your GP or seek emergency medical care as appropriate.