Can Your Calf Muscle Cause Your Knee To Hurt?

Now that's some very defined soleus muscles

Really? You must be wondering how and why after looking at the title of this week's post. Well, my last patient today had knee pain caused by her soleus (or calf) muscle. She had recently been doing a lot of step ups in her gym classes and her knee pain started soon after.

Runners' knee or patellofemoral joint pain (pain under the kneecap) is very common in runners. I've written before about how this may be due to heel striking, heavy landing and hip dysfunction.

There is also some evidence where the length of the soleus muscle can influence patellofemoral joint pain (PFP). It has been suggested that in runners with PFP, there is a greater activation in the muscle compared to runners without knee pain (Piva et al, 2005).

See soleus after you cut away gastrocnemius

Your calf muscles consist of the more superficial gastrocnemius muscles and the deeper soleus muscle. If you peel off the gastrocnemius muscles, the soleus muscle lies underneath. Together they end as the Achilles tendon finishing at the heel bone (picture above).

The soleus muscle is largely thought to help with our posture as it is mostly made up of Type I slow twitch muscle fibres. The gastrocnemius muscle is made up of mainly Type II fast twitch fibres.

The fast twitch muscles of the gastrocnemius allows you to sprint. However, the gastrocnemius muscles tire easily.

The slow twitch soleus muscle is very important for your walking and running. Since they're more fatigue resistant, you use them a lot chalking up mileage whenever you run.

One of the main functions of the calf muscles is to absorb shock. If they're overused, they can't absorb shock well, your knee takes more of the load and you get knee pain.

A very simple way to take load off your soleus muscle is to take smaller steps when walking or running. Increasing your step rate, especially while running will ensure you're not over striding and heel striking. This reduces impact loading and lessens your chances of knee pain.

Reference

Piva SR, Goodnite EA et al (2005). Strength Around The Hip And Flexibility Of Soft Tissues In Individuals With And Without Patellofemoral Pain Syndrome. JOSPT. 35(2): 793-801. DOI: 10.2519/jospt.2005.35.12.793.