Hamstring tendonitis occurs when the soft tissues that connect the muscles of the back thigh to the pelvis, knee, and lower legs become inflamed. Tendonitis is often brought on by overuse and causes acute, or immediate, pain that decreases with rest and minor first aid. Most people can return to regular activity after a week or so. Full recovery typically involves rehabilitative exercises and takes several weeks.

The hamstring muscle group includes two inner, or medial, muscles. These muscles are known as the semitendinosus and semimembranosus. There’s also an outer, or lateral, muscle — the bicep femoris. Tendons, a type of connective tissue, attach these muscles to the pelvis, knee, and shinbones, and allow the knee to flex and the hip to extend.

When hamstring tendons are overused or misused, tiny tears occur, causing inflammation and pain.

Cases of hamstring tendonitis can be lateral or medial depending on the muscles involved. They can also be described as distal, involving the tendons around the:

  • knee
  • back thigh
  • calf

Tendon inflammation is technically called tendinitis, but popular use of tendonitis has made the terms interchangeable. Tendonitis is often confused with tendinosis, a chronic condition caused by repetitive overuse or injury.

The most common symptoms of hamstring tendonitis include:

  • sharp, burning pain
  • muscle and joint weakness
  • aching or dull throbbing
  • muscle and joint stiffness
  • swelling or inflammation

Symptoms get worse with further exercise or use, and are often worse after long periods of inactivity, like sleeping or sitting.

Symptoms often worsen in the first few hours immediately following injury, then gradually lessen. Tight or inflamed hamstring tendons often cause radiating pain in the:

  • knee
  • thigh
  • buttock
  • lower back

To properly diagnose hamstring tendonitis a doctor or physiotherapist will order an MRI scan or X-ray. They will use these images to confirm tendonitis, rule out other causes, and evaluate the injury to guide treatment plans.

In some cases, you can self-diagnose hamstring tendonitis at home. Any activity that activates the hamstring and causes a sudden spike in pain is likely a sign of hamstring tendonitis. A few different stretching tests are considered telltale signs of the injury.

One test involves resting the foot on a solid surface, straightening the leg to a 90-degree angle, and pulling or flexing the foot toward the chest. An alternative test involves lying on your back with a bent knee and slowly straightening the leg to a 90-degree angle. Both stretches can be done with or without the use of an assist like a rope, belt, or yoga strap. If the stretches cause pain, you likely have hamstring tendonitis.

For most people, using the RICE method (rest, ice, compression, and elevation) for 72 hours is enough to treat symptoms.

Ice causes blood vessels to constrict, reducing blood flow and, in turn, inflammation. Ice should be applied for a maximum of 10 minutes at a time. After a 20-minute break, ice can be reapplied a few times following the same 10-minute on, 20-minute off schedule as needed. Icing sessions can be done two or three times throughout the day.

Compressing and elevating the injured area also lessens inflammation by reducing blood flow to the region.

Over-the-counter nonsteroidal anti-inflammatories like ibuprofen (Advil, Motrin) and naproxen (Aleve) can make symptoms more manageable in the days following the injury. If intense pain continues for more than a few days or doesn’t respond well to basic treatment, talk to a doctor.

When injured tissues are forced into use too soon they often don’t entirely recover. Weakened tendons are far more likely to become reinjured. The more times the same tissue is damaged, the greater the chances of developing long-term damage.

It generally takes people several days to start to feel major relief, and six weeks or more to feel entirely better.

Avoid anything that activates the tendon for the first 48 hours. After that, exercises should only be done if they don’t cause additional pain.

In the first week after injury you can start reintroducing slow, steady movements that focus on maintaining general strength. A good starting exercise is isometric knee flexes, where the injured hamstring is placed over the opposite leg and contracted at 30, 60, and 90-degree angles, as comfortable.

It’s usually safe to begin range of motion, lengthening, and strengthening exercises after a week or so. An easy starting point is a single leg windmill. To do this exercise:

  1. Rest the uninjured leg on a chair while keeping the other straight.
  2. Reach downward with a flat back.
  3. Hold the stretch for 30 seconds.

You can add handheld weights to make the stretch more difficult.

The Nordic hamstring exercise is another useful stretch:

  1. Kneel and bend forward as far as comfortable with a neutral hip.
  2. Have a helper restrain your feet.
  3. Hold the stretch for 30 seconds.

After a few weeks, you can start adding additional exercises that work the muscle in a lengthened state. A good exercise involves lying on the back with a bent knee and using an elastic resistance band to create an opposing force while slowly flexing the knee.

Four to six weeks after the injury, you can start adding more intensive exercises like squats, hamstring curls, and hamstring bridges. These can help strengthen the entire region and prevent future injury.

A majority of tendonitis cases are caused by overuse. Running, kicking, and jumping activities that involve intensive knee flexion and hip extension are common causes. Sports that involve sudden bursts of use or abrupt changes in speed and direction, like football and soccer, are often common causes for this injury.

Overuse can also occur when the tendons are forced to work for longer than normal. Failing to warm up can also cause tendonitis. Warming up helps to gradually prepare muscle tissue for exercise.

In some people tendonitis occurs because of imbalanced thigh muscles or weak core muscles. Poor posture, especially slumping of the lower back or lumbar region, has also been linked to tendonitis.

This injury is usually treatable with rest, ice, compression, and elevation. Once the pain starts to improve, slowly reintroduce exercise, starting with gentle stretches to target the hamstring.

If your pain doesn’t improve, or if you are continually injuring your hamstring, see a doctor.