Calf Strain Assessment & Diagnosis

Calf strain assessment

A thorough assessment is required to properly diagnose a calf strain injury. We outline some techniques a therapist may use to assess and diagnose a calf strain.

The following examples are for information purposes only. We highly recommend seeing a sports injury professional or Doctor to receive a full assessment of your injury.

Pain in the calf muscle is often due to a strain, however, there are other conditions which could cause similar symptoms, including deep vein thrombosis and contusions. A full assessment helps the therapist to determine the most likely cause of the pain.


A calf muscle tear is graded from 1 to 3, with grade 3 being the most severe. A grade 1 will not normally need professional treatment whereas grade 2 or 3 injuries, depending on their severity, may require more specialist treatment and rehabilitation advice from a sports injury professional.

Grade 1 symptoms

A Grade 1 calf strain is a minor tear with up to 25% of the muscle fibres affected. The athlete may feel either a twinge of pain in the back of the lower leg or a feeling of "tightness". They may be able to carry on playing or competing without pain or with only mild discomfort in the calf. However, after exercise, there is likely to be "tightness" and/or aching in the calf muscles which can take up to 24 hours to develop.

Grade 2 symptoms

Symptoms of a Grade 2 strain will be more severe than a grade one, with up to 90% of the muscle fibres torn. There will be a sharp pain at the back of the lower leg and usually significant pain on walking afterward. There is likely to be swelling in the calf muscle with mild to moderate bruising, however, this may take hours or days to be visible. On strength testing the muscle, the pain will be felt on resisted plantar flexion (pushing the toes and foot downwards towards the floor) against resistance. Tightness and aching may be present in the calf muscle for a week or more before subsiding.

Grade 3 symptoms

Grade 3 injuries involve 90-100% of the muscle fibres and are often referred to as "ruptures". The athlete will definitely be able to recall exactly when the injury occurred and this will be associated with severe immediate pain at the back of the lower leg. In these situations, the athlete will be unable to continue/finish exercising and will often be unable to walk due to weakness and pain. This level of injury also presents considerable bruising and swelling although this may take hours to be visible. On strength testing, the athlete will be unable to even contract the calf muscle at all and in the case of a full rupture, a gap in the muscle can usually be felt. This is due to a deformity where the muscle is torn and the top part of the muscle may bunch up towards the top of the calf which is clearly visible.


Assessment of any injury should include questions concerning the patient's general health, previous injuries, and current injury. The aim of these questions is to determine which structure may be causing the pain and what treatment is appropriate. Following this, the therapist will perform a series of tests, often including:


Observation is usually the first point of any injury assessment. The therapist usually observes the patient in both standing and laying positions, looking closely for swelling, bruising and deformity, as well as postural issues such as overpronation.


The therapist should palpate the entire calf area, looking for tight or painful areas.

Range of Motion

The therapist will usually assess both active (the patient moves) and passive (the therapist moves the joint) range of motion at the ankle with the knee both straight and then bent. Calf strains usually present with pain and weakness on active plantarflexion. Passive range of motion is usually pain-free as the muscles are not contracting, although the end of range into dorsiflexion (toes pointing upwards) may be painful as the muscles stretch.

Resisted Muscle Tests

These tests are used to assess muscular strength compared to the other side. Again they should be tested with the knee straight and then bent: The therapist applies resistance as the patient plantarflexes the ankle (points the foot away). A positive result is a pain on contraction and weakness compared to the other leg.

Special Tests

Thompson's test for complete muscle rupture. The therapist squeezes the calf muscles observing for movement at the ankle into plantarflexion (pointing the toes away). If no movement is seen, suspect a total rupture of one or both calf muscles.

Functional Tests

Assessing the ability to carry out the following tasks gives the therapist a clear picture of the patient's current abilities. They can also be used as objective markers to show progression once treatment and rehabilitation have been initiated.

Calf Raise

Single leg calf raises assess the ability to hop on spot with one leg- only do so if previous tests have not proved conclusive or have not elicited any symptoms. Additional imaging tests such as ultrasound and MRI may be needed to fully diagnose the injury.

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