A medial gastrocnemius strain (MGS) is a specific type of injury to the calf muscle in the back of the leg. The strain occurs when the muscle stretches too far, tearing the tendon and muscle portion of the calf.

The strain is commonly known as “tennis leg” because it’s so common among tennis players. Generally, it doesn’t require surgery, but it hurts. In fact, people who experience it often say it feels as though they’ve been kicked hard or shot in the leg. So as you might guess, it takes a while to recover from the strain—at least a month.

This article explains the symptoms, causes, diagnosis, and treatment of a medial gastrocnemius strain.

The Calf Muscles

The calf consists of three major muscles: the medial and lateral gastrocnemius and the soleus muscles. They unite to form the Achilles tendon to attach to the heel. The most commonly injured muscle when a calf strain occurs is an injury to the medial gastrocnemius muscle.

Symptoms

The symptoms of a medial gastrocnemius strain can include:

It is important to determine whether the gastrocnemius or the soleus is injured in order to give the appropriate treatment and prevent a recurrence.

  • Decreased flexibility or stiffnessPain in the back of the leg (more on the inner side)Swelling of the calfBruising of the calf down to the ankleAn audible pop or snapping noise at the moment of injuryWeakness or a complete lack of function

The symptoms of a calf muscle strain depends on the severity of the injury. For example, a minor injury might result in tightness in the calf. A serious injury could trigger severe pain or difficulty extending the lower leg.

Causes

The umbrella term may be “tennis leg,” but calf injuries can be caused by virtually any sport, and especially running and soccer. The gastrocnemius muscle crosses the knee joint and the ankle joint, flexing the foot and the leg.

Sudden changes in direction when running can overstretch the muscle and lead to a tear, especially in the position where you are flexing the ankle and extending the knee at the same time. Injuries can also happen in everyday life in physically demanding activities. To help you visualize the possibilities, you could strain your calf muscle if you:

  • Lunge or push off on one leg, such as if you run to catch a bus or chase a wayward childHurriedly climb stairsExperience a direct hit to the back of your lower legTrip and contort your leg to compensate for falling

Diagnosis

Your healthcare provider will listen to your report of the injury and do a physical examination. A diagnostic ultrasound is the best way to confirm a gastrocnemius tear and grade the injury.

Other diagnostic tools can help, too. For example, if a deep venous thrombosis (a blood clot in the veins) is suspected, a Doppler ultrasound may be done. Magnetic resonance imaging (MRI) is another option.

Treatment

Treatment of a medial gastrocnemius strain can usually be accomplished with simple steps. Initially, patients follow the “RICE” regimen:

Grades Explained

Calf muscle strains are graded by their level of severity:

  • Rest is vital. Sometimes, people will use crutches for a few days or a week to allow the most significant pain symptoms to subside.Ice on the calf muscle can ease pain, reduce swelling, and counteract inflammation. Ice is one of the most helpful treatments in the early phase of recovery.Compression can control swelling, support the muscle, and reduce spasms. Even a simple compression sock or sleeve can do wonders.Elevation is one treatment that many people tend to undervalue—until they lower the leg and try to stand up but can’t because of swelling. Elevating the calf above the heart can be hugely beneficial in reducing swelling.

It’s best not to use heat or massage in the first phase of therapy as the tactics might increase the risk of hemorrhage. Once this early treatment phase is over, patients begin therapeutic activities and gentle stretching exercises tailored to their specific injury.

Summary

A medial gastrocnemius strain leaves little doubt that something serious has happened. A sudden, lurching or pulling movement can cause sharp pain, swelling, bruising, or weakness in the lower leg. The strain is often referred to as “tennis leg,” though it can happen while playing other sports or undertaking physical activities, especially running. You might even hear a popping or snapping sound at the moment the tear occurs. The strain is graded on a scale of 1 to 3 (with 3 being the worst), and a therapy treatment plan is designed accordingly.

The typical recovery time from a medial gastrocnemius strain is between four and six weeks. You must be able to walk without pain before your doctor will give you the all-clear to return to exercise and sports.

A Word From Verywell

Tennis leg is most common among middle-aged people, presumably because their muscles are often just starting to weaken and so are more vulnerable to injury. Even if you don’t play tennis, you don’t want to experience tennis leg. It can be surprisingly painful. And if you do play tennis, then you might guess that the best “treatment” of all is prevention. So be sure to warm up before playing. Doing 10 minutes of cardio work followed by 10 minutes of stretching should serve you well.

Frequently Asked Questions

  • Is a sore calf muscle related to tennis leg?
  • It is possible that a sore calf muscle is related to tennis leg, but soreness is more often associated with a muscle cramp or muscle strain in the lower leg. Pain caused by tennis leg is often described as intense due to a tear in the tendons and muscle, but the degree of pain is likely related to injury severity. If the tennis leg injury was minor, it may simply result in calf tightness.
  • Do calf splints help treat medial gastrocnemius strain?
  • In some cases, calf splints or casts may help treat medial gastrocnemius strain. Specifically, a certain type of splint known as a short leg cast can assist in movement and weight-bearing of the leg alongside crutches. Depending on injury severity, a splint may not be necessary.
  • What should I do if I hear a calf muscle pop?
  • If you hear a calf muscle pop, it may be a good idea to immediately contact a healthcare provider. An audible pop could be a sign of a medial gastrocnemius strain. Even if the strain is minor (grade 1), if it is not properly treated, the injury could become worse.

It is possible that a sore calf muscle is related to tennis leg, but soreness is more often associated with a muscle cramp or muscle strain in the lower leg. Pain caused by tennis leg is often described as intense due to a tear in the tendons and muscle, but the degree of pain is likely related to injury severity. If the tennis leg injury was minor, it may simply result in calf tightness.

In some cases, calf splints or casts may help treat medial gastrocnemius strain. Specifically, a certain type of splint known as a short leg cast can assist in movement and weight-bearing of the leg alongside crutches. Depending on injury severity, a splint may not be necessary.

If you hear a calf muscle pop, it may be a good idea to immediately contact a healthcare provider. An audible pop could be a sign of a medial gastrocnemius strain. Even if the strain is minor (grade 1), if it is not properly treated, the injury could become worse.