Why do my calf muscles hurt?

Know your calf muscle Anatomy

Each calf comprises two main muscles – the Soleus and the Gastrocnemius. The Soleus has a long, wide muscle belly that extends the length of the back of the Tibia (shin) bone. The Gastrocnemius is the muscle on the top half of the calf and comprises a medial and lateral head which both overlay the Soleus. Together the Soleus and Gastrocnemius join to form the Achilles tendon, which attaches to the heel bone allowing us to push off when we walk, run and stand on tip-toe.

5 Calf Muscle injuries

1.  Delayed Onset Muscle Soreness

Delayed Onsets Muscle Soreness (aka DOMS) is often felt as stiffness in muscles following a harder-than-usual session. It may start anywhere from 2 hours to 2 days after the activity and can last a few days. For newer runners, this could arise after any session, but more experienced runners might feel it after a session that is longer and/or faster than usual. DOMS may also be felt if starting a new activity – such as calf raises in the gym – or doing a new drill such as hill sprints or skipping.

DOMS is generally nothing to worry about; in fact, it may actually be somewhat beneficial. It’s been found that experiencing DOMS once and then training again within a few days can help to reduce it coming back the next time. Interestingly, taking anti-inflammatory medications (such as Nurofen or Voltaren Rapid) can reduce the discomfort of DOMS initially but you are more likely to experience DOMS again as your body hasn’t learned to adapt to it.

2.  Calf Muscle Tightness

Calf muscle tightness from DOMS should settle down within a few days after the aggravating activity. Some runners however may experience an ongoing sensation of tightness which can be due to:

• • • Insufficient recovery between sessions
    • Too much intense exercise
    • Poor calf muscle flexibility or endurance
    • Incorrect footwear
    • or some combination of the above.

Ensuring adequate rest (and getting enough sleep) between high intensity sessions (e.g. intervals, hills, gym) should help to reduce the feeling of tightness. If calves feel tight even after easy-paced running then it may be worth looking at whether your shoes suit your feet and legs. You can test your calf muscle length by standing barefoot with the front of your toes 10cm away from a wall. You should be able to comfortably squat and touch your knees on the wall without lifting up your heels.

 Runners with a reduced calf muscle length may struggle to wear shoes with less than an 8mm heel-to-forefoot drop. Calf muscle stretches may help somewhat, but adding a heel wedge under the insole can give instant relief.

3.  Calf muscle tears

Calf muscle tears are fairly common in runners and can result in pain and an inability to run or walk comfortably. They often strike at inopportune times – such as during the sprint finish of a race and can leave the runner unable to run for weeks, or even months. With correct care, healing time can be reduced, safely returning you back to running.

4.  Acute muscle tears

Small muscle tears (microtears) occur nearly every time that we run, however they are usually so small that they heal by the next time that we run. Much like DOMS they can help us to become stronger once they heal. More substantial acute tears can happen when there’s insufficient healing time between running sessions, or more stress is put on the muscle than it can handle – often during sprinting and running uphill/stairs and greater damage occurs.

Risk factors for acute muscle tears include:

• • • Inadequate warm-up
    • Incorrect or worn out shoes
    • Running on a steeply cambered road or steep hill
    • Tight and/or fatigued calf muscles
    • Running with increased speed or power

The tear may feel like a burning sensation, and intense tightness and is sometimes accompanied by a ‘pop’ sensation as it tears. Depending on the severity of the injury, normal walking may feel slightly uncomfortable to near impossible. The medial (inside) head of the Gastrocnemius is a common site for acute muscle tears but can occur in either of the calf muscles.

5.  Chronic muscle tears

Poorly healed acute muscle tears are likely to continue causing pain due to scar tissue which forms during the healing process. Scar tissue is less flexible and can pull on surrounding healthy muscle tissue creating further damage. Running with pain in a muscle will mean that it doesn’t function properly and can expose you to risk of other injuries.

In addition to the risk factors for acute muscle tears, the following may contribute to chronic muscle tears:

• • • History of the poorly healed calf muscle or Achilles tendon injuries
    • Leg length difference
    • Muscle strength imbalance
    • Poor foot biomechanics (excess or insufficient pronation)
    • Training program errors

How to treat a calf muscle tear

Immediate treatment for calf muscle tears involves:

• • the use of calf compression
  • intermittent ice packs
  • ceasing pain-provoking activities (including running) for 2-3 days.

After the first few days:

• • See a physiotherapist to help judge the severity of the injury and begin a rehabilitation program.
  • Consider massage as it’s useful to help encourage faster healing and reduce scar tissue in the muscle. 

Strength exercises:

The different calf muscles each need their own specific strength exercises. The goal of rehabilitation is to help strengthen and regain flexibility in the muscle in order to return to running and avoid injury reoccurrence.

Chronic or Recurring tears: 

In cases of chronically reoccurring muscle tears, it is useful to see a podiatrist at intraining to have your biomechanics, footwear and gait assessed as potential causes of injury.

Two injuries that mimic calf pain

Here are two other ‘not to be missed’ injuries that can mimic calf pain.  

1.  Tibial Stress Fractures

If you’ve been running for at least a few weeks and calf pain develops without a clear cause other than an increase in running training, it is unlikely to be DOMS, but may be due to a stress injury to the Tibia (shin) bone. When these occur on the posterior (back) side of the bone they can easily be confused for calf muscle injuries. If not managed well, bone stress injuries can progress to stress fractures which require complete rest from impact activities such as running for around 2 months.

2.  Calf compartment syndrome

Compartment Syndrome refers to an increase in pressure in a muscle compartment. Calf muscles are surrounded by a thin layer of strong tissue (fascia) that has a limited ability to stretch and expand. Compartment syndrome tends to occur more commonly in runners that are new to the sport or have dramatically increased their training. The compartment pressure increases due to a combination of recently increased muscle size, and/or the presence of either more blood or swelling in the muscle. Calf compartment syndrome may develop from calf muscle tears or tibial stress fractures due to increased swelling from these injuries.

Calf compartment pressure usually reduces after exercise has stopped. The pressure that doesn’t reduce shortly after exercising is a medical emergency particularly if feelings of coldness or numbness are felt in the foot. This should be treated urgently in a hospital setting.

Enjoy your running but take care!

If you are new to running or starting back after some time away from the sport, it is important to take care of building your running distance and speed gradually. Calf soreness can be a sign of one of several injuries and is best treated early,

Finally, if you are still baffled as to why you are getting calf pain… check your shoes.  You’d be surprised at how often old or the wrong shoes are the culprit!

Stay injury free, and keep your routine for a great year of running.  

Doug James, physiotherapist and podiatrist

If you have developed a running injury, contact 07 3367 3088 to book an appointment today.