calf muscle

What is a Calf Strain?

The calf muscles consist of the Gastrocnemius muscle which is the big muscle at the back of the lower leg and the Soleus muscle which is a smaller muscle lower down in the leg and under the Gastrocnemius.

Gastrocnemius is the larger of the two muscles which attaches above the knee joint and inserts into the heel bone via the achilles tendon. The Soleus attaches below the knee joint and then also to the heel via the achilles. Either of these two muscles can be strained (torn). 

Both muscles act to plantarflex the ankle (point the foot away from the body). As gastrocnemius attaches above the knee it also helps with bending the knee. In this position, with the knee bent, soleus becomes the main plantarflexor. If the Soleus muscle is damaged you might get pain lower in the leg and also pain when you contract the muscle against resistance with the knee bent.


  • Sudden sharp pain at the back of the calf muscle.
  • Depending on severity the athlete may be unable to walk properly.
  • There may be bruising.
  • Calf muscle strains are graded 1,2 or 3 depending on how bad the injury is.

Grading Muscle Strains

Muscle strains are graded from 1-3, with grade 1 being a minor tear, with up to 10% of fibres involved. A grade 2 tear involves up to 90% of the muscle fibres and a grade 3 is over 90% of fibres torn, or a full rupture. This usually occurs at the muscular tendinous junction or the achilles tendon itself.

Grade 1:

  • A twinge of pain in the back of the lower leg.
  • May be able to play on.
  • Tightness and aching in the 2-5 days after.

Grade 2

  • Sharp pain in the back of the lower leg.
  • Pain when walking.
  • There may be swelling in the calf.
  • Mild to moderate bruising.
  • Pain on resisted plantarflexion.
  • Tightness and aching for a week or more.

Grade 3

  • Severe immediate pain.
  • A sudden pain at the back of the leg, often at the muscular tendinous junction (see image below).
  • Inability to contract the muscle.
  • Considerable bruising and swelling.
  • In the case of a full rupture, often the muscle can be seen to be bunched up towards the top of the calf.

What can the athlete do?

  • Applying R.I.C.E. (Rest, Ice, Compression, Elevation) is essential.
  • Cold therapy should be applied as soon as possible to help to quickly stop any internal bleeding.
  • Use a compression bandage or sleeve.
  • See a sports injury professional who can advise on treatment and rehabilitation.
  • Wear a heel pad to raise the heel and shorten the calf muscle hence taking some of the strain off it. It is a good idea to put heel pads in both shoes or one leg will be longer than the other creating an imbalance and possibly leading to other injuries including back injuries.

What could a sports injury specialist do?

  • Prescribe anti-inflammatory medication e.g. ibuprofen which is beneficial in the first few days after the injury.
  • Use ultrasound treatment.
  • Use sports massage techniques for calf muscles after the initial acute phase.
  • Prescribe a full rehabilitation programme.

Once the initial healing has taken place it is essential the lower leg is fully strengthened in order to reduce the likelihood that the injury will reoccur or have an adverse effect on future performances.