A hamstring injury is a strain or tear to the tendons or large muscles at the back of the thigh.
It's a common injury in athletes and can occur in different severities. The three grades of hamstring injury are:
The length of time it takes to recover from a hamstring strain or tear will depend on how severe the injury is.
A minor muscle pull or strain (grade 1) may take a few days to heal, whereas it could take weeks or months to recover from a muscle tear (grade 2 or 3).
The hamstrings are tendons (strong bands of tissue) at the back of the thighs that attach the large thigh muscle to the bone.
The term 'hamstring' also refers to the group of three muscles that run along the back of your thigh, from your hip to just below your knee.
The hamstring muscles aren't used much while standing or walking, but they're very active during activities that involve bending the knee, such as running, jumping and climbing.
A hamstring injury can occur if any of the tendons or muscles are stretched beyond their limit.
They often occur during sudden, explosive movements, such as sprinting, lunging or jumping. But they can also occur more gradually, or during slower movements that overstretch your hamstring.
Recurring injury is common in athletes and sportsmen, as you're more likely to injure your hamstring if you've injured it before.
Mild hamstring strains (grade 1) will usually cause sudden pain and tenderness the back of your thigh. It may be painful to move your leg, but the strength of the muscle shouldn't be affected.
Partial hamstring tears (grade 2) are usually more painful and tender. There may also be some swelling and bruising at the back of your thigh and you may have lost some strength in your leg.
Severe hamstring tears (grade 3) will usually be very painful, tender, swollen and bruised. There may have been a "popping" sensation at the time of the injury and you'll be unable to use the affected leg.
Most hamstring injuries can be cared for at home using the techniques outlined below.
Consider seeing your GP if you have any concerns about your injury, particularly if you think it's a severe injury, it's not healing, or your symptoms are getting worse.
Your GP can also advise you about when you can return to your normal activities and what exercises you should do to aid your recovery in the meantime. They may be able to refer you to a physiotherapist for specialist treatment in some cases.
Recovering from a hamstring injury may take days, weeks or months, depending on how severe the strain or tear is.
A completely torn hamstring (grade 3) may take several months to heal and you'll be unable to resume training or play sport during this time.
During the first two or three days, you should care for your injury by following the steps below.
Short-term use of oral NSAIDs, such as ibuprofen tablets, can also help reduce swelling and inflammation. However, these aren't suitable for everyone. Check the leaflet that comes with your medication to see if you can take it.
Returning to strenuous exercise too quickly could make your injury worse, but avoiding exercise for too long can cause your hamstring muscles to shrink and scar tissue to form around the tear.
To avoid this, you should start doing gentle hamstring stretches after a few days, when the pain has started to subside.
Your GP can give you further advice and, if necessary, refer you to a physiotherapist for a suitable exercise programme.
To avoid injuring yourself again, you should only return to a full level of activity when your hamstring muscles are strong enough. Your physiotherapist or GP will be able to advise you about this.
Many people need to avoid sports for at least a few weeks, but the length of time you need off will depend on the severity of your injury.