Leg · Skeletal muscle
Hamstrings (Back of Thigh)
The hamstrings are the three muscles at the back of the thigh that bend the knee and extend the hip. They are commonly strained in sports involving sprinting.
What it is
The hamstrings are a group of three muscles running down the back of the thigh, from the sitting bone to below the knee.
Where it is
The back of the thigh, between the buttock and the knee.
What it does
Bend (flex) the knee and straighten (extend) the hip; important in walking and running.
Everyday use
Walking, running, bending the knee and bending forward from the hips all use the hamstrings.
When things go wrong
Common problems affecting the hamstrings (back of thigh)
- Hamstring strain or tear (a very common sports injury)
- Tightness contributing to back or knee issues
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. Sudden severe symptoms — such as crushing chest pain or collapse — are an emergency; call 999.
Looking after it
Keeping it healthy
Warming up, building strength and flexibility, and increasing sprinting loads gradually reduce hamstring injuries.
Did you know?
An interesting fact
Hamstring strains are one of the most common injuries in sports involving sprinting, such as football and athletics.
Answers
Hamstrings (Back of Thigh): frequently asked questions
What do the hamstrings do?
The hamstrings bend the knee and extend the hip, and are heavily used in walking, running and bending forward.
Why are hamstring injuries so common in sport?
The hamstrings work hard and stretch rapidly during sprinting and kicking, which can overload them and cause a strain or tear, especially without a good warm-up.
Related muscles
Explore the leg
Sources
Where this is drawn from
- NHS — Muscles and movement
- Gray's Anatomy for Students
- TeachMeAnatomy — muscular system
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