What is a calf strain?

What is a calf strain?

Calf strains are a common injury that occurs to one of the muscles located at the back of your lower leg.


Muscles of the calf:

There are three muscles located in this area which come together to form the Achilles tendon. These are the:

  1. Gastrocnemius
  2. Soleus
  3. Plantaris


Out of these three muscles; the gastrocnemius is the most commonly injured during a calf strain. This is because the gastrocnemius extends over two joints (the back of the ankle and the back of the knee) and experiences high forces travelling though the muscle during walking and running – which unfortunately makes this muscle slightly more susceptible to injury. The most common location for calf strains are the medial head of the gastrocnemius or at the junction of the muscle into the Achilles tendon.

Symptoms of a calf strain:

The symptoms of a calf strain include a sudden sharp pain at the back of the lower leg, or a gradual tightening sensation during activity.


Causes of a calf strain:

Calf strains commonly occur in sports involving high-speed running and sudden changes in speed. They can also occur when a person increases their running distance, and in many cases occur specifically when the muscle is forced into a sudden overstretch whilst it is contracted. For example, when a person is running and they step up onto a curb forcing the ankle into sudden into dorsiflexion, which over stretches the calf causing a strain.


Diagnosis of a calf strain:

The diagnosis of a calf strain is given after the therapist has taken a detailed history, inquiring about the mechanism of injury, predisposing factors and conducted a thorough physical examination. During the physical examination therapist will examine the leg for signs of swelling, bruising and tenderness to touch. The therapist will also observe the foot and ankle in standing and supine, assess the patients range of movement and muscle strength as well and ask the patient to perform specific functional movements with the aim to elicit a reproduction of symptoms.

The aim of assessing functional movements is to establish the “load tolerance” of the calf musculature. An example of a test used to determine load tolerance of the calf is a standing single leg calf raise. The test is performed barefoot and with a tempo of 2 seconds up and 2 seconds down. Pain on this test may implicate the gastrocnemius (vs soleus). The assessor needs to monitor quality of movement (any compensation strategies e.g. bending the knee, rolling onto outside of foot, rocking the body forwards to generate momentum) and symmetry side to side. If the therapist suspects the strain is located in the soleus (the muscles underneath the gastroc) the same test can be performed however with the knee bent to 60 degrees. If the patient cannot tolerate single leg testing double leg testing can be used.

Muscle strains are graded from 1 – 3 depending on their level of severity. Different grades of strains will demonstrate differing symptoms as seen below.

Grade 1 Signs & Symptoms:

Sharp pain at time of injury – May have feeling of tightness – May be able to continue activity without pain / mild discomfort – May have post activity pain / tightness.

Grade 2 Signs & Symptoms:

Sharp pain at the time of activity – Unable to continue activity – Pain with walking – Swelling in muscle – Mild to moderate bruising may be present – Pain with active plantar flexion – Pain & weakness with resisted plantarflexion – Loss of dorsiflexion.

Grade 3 Signs & Symptoms:

Severe and immediate pain in the calf often at the musculotendinous junction – Unable to continue with activity – May present with considerable bruising, swelling and within hours of injury – Inability to contract calf muscle – May have palpable defect – Positive thompson test.


Differential Diagnosis of a calf strain:

  • Deep vein thrombosis
  • Deep vein thromboembolism
  • Neural conditions
  • Claudications conditions (popliteal artery entrapment syndrome)
  • Bone sarcomes of the tibia


Treatment for a calf strain:

Treatment of a calf strain involves a combination of manual therapy and exercise rehab. The rehab program will generally follow a progression from isometric exercises, through to eccentrics, isotonics and finishes with plyometrics and graded return to sport to ensure an injury free return to soft.

Manual therapy will often involve soft tissue massage and trigger point release of the calves as well as stretches towards the end of the program. The therapist may also choose to apply K- Tape or dry needling can be used to speed up soft tissue healing.

In addition it is important that during the rehab program the therapist performs a biomechanical assessment to determine if there are any additional factors in a persons movement patterns which may be predisposing them to injury.


Post by: Physiotherapist Sarah Loveband