Hamstring Strain

hamstring strain

Hamstring Strains

The “Hamstring” is the common term for the three large muscles located on the back of the thighs. These muscles are run from the hip down to the knee joint, and are very important for powerful movement such as jumping, running, or climbing. Because of this, they are most commonly strained during more aggressive activities. But how do you know if you pulled a hamstring? 

What Causes Hamstring Strain?

The three muscles that make up the hamstring are called the Semitendinosus, the Semimembranosus, and the Biceps femoris. These muscles all work together to pull and push the leg and to bend and straighten the knee. As such, these muscles are often contracting and relaxing over and over again. But if a sudden movement occurs which pulls too hard on the muscles, they can rip or tear. This happens most often during physical activity with sudden movements, where the individual did not stretch the muscles prior to the activity. This is usually what causes a hamstring strain. 


There are three tiers of muscle strains that are categorized due to severity of the strain. These apply to hamstring strain as well. 

Grade 1 Strain

This level for a hamstring strain has symptoms that are relatively mild. The patient may feel pain and tenderness of the hamstring muscles and usually feels this pain when performing physical activities. This is usually treatable at home. 

Grade 2 Strain

A grade 2 strain is categorized by one of the muscles in the hamstring tearing. This is usually much more painful and it can sometimes be seen through the skin. This could vary due to the severity and placement of the tear, but most patients experience pain, tenderness, swelling, and bruising of the back of the thigh. Some patients also may feel weakness in the injured leg. 

Grade 3 Strain

A grade 3 strain is much more serious as it means that a muscle has been torn completely through. Some patients feel or hear a pop when this occurs. The patient will feel pain, weakness, and may have visible tears in the muscle, or bunching of the muscles. This can usually be seen on the back of the thigh and the person may not be able to walk or run at all. Most patients will not be able to straighten the affected leg all the way. This usually needs immediate care, and it could also mean that the patient’s muscle has pulled away from the bone, called an avulsion. This is very serious and must be repaired. 

Most hamstring strains occur in the central part of the muscles, called the muscle belly. However, a muscle tear can happen in any part of the muscle, and may not be directly visible through the skin. This is why getting a diagnosis is so important. 

Diagnosis of Pulled Hamstring 

Most doctors will start with a physical examination of the hamstring, so they will touch the area to feel the underlying muscles and see if there are any abnormalities. They will also look at the area to see if there is visible swelling or bruising. They may then send the patient for some imaging tests such as an ultrasound, MRI, or CT scan. These scans can show what the inner muscle looks like and can see if there is a tear that may not be visible. They can also determine if the muscle has detached itself from the bone (avulsion). 

Treatment of Hamstring Strain

Treatment of a pulled hamstring depends on the grade of the strain. This can also vary depending on any complications or other injuries that may have been sustained. 

Grade 1 Treatment

For most patients with a minor strain, the doctor may recommend rest, ice, compression and elevation (RICE) treatment, which should help the muscle to repair itself. This can take a few weeks, but most patients see improvement in the first few days and are able to return to full activity shortly. 

Grade 2 Treatment 

For a muscle tear, a doctor may recommend physical therapy, pain medications, and the RICE method. If it is more severe or does not get better, they may recommend other options.

Grade 3 Treatment 

For the more serious muscle tears, the patient may need over 3 months of recovery time and to avoid playing sports or strenuous activity. They may require surgery to repair the torn muscle as well, but it depends on the nature of the tear and where it occurred. Each patient is different and may require a specific treatment plan to best care for their injury.