Many runners will experience soleus pain at some point in their running careers due to various reasons, including overusing the soleus muscle. The soleus is one of the muscles in the back of your lower leg, and is one of two muscles that form the triceps surae (the other is the gastrocnemius, which lies over top of the soleus). The soleus attaches at the top of the tibia and fibula, and runs down to insert at the Achilles tendon. It is responsible for plantar flexion of the ankle, which means it is necessary to help you walk and run.
When you do a lot of hill work, or suddenly increase your frequency, duration, or intensity of your runs, you may experience a dull, throbbing ache in the middle of your calf. This soleus pain is due to overuse, and is easily treated with rest, ice, and stretching. If you feel it is necessary, over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may help with pain and inflammation. Apply ice for 10 to 15 minutes at a time, once an hour, until the discomfort subsides. To prevent future soleus pain like this, increase your workouts gradually, and make sure you have proper footwear.
Over-Pronation and Flat Feet
Another cause of soleus pain may arise from improper gait or foot support. Normally, your feet roll slightly inward when you run, to adapt to the ground. For someone with over-pronation, their feet turn past the point of normal pronation necessary for gait. When this happens, your arch collapses and flattens, the soft tissues in your feet stretch, and you experience fatigue, lower leg pain and even deformities. To prevent soleus pain as a result of over-pronation, special insoles and shoes help support your feet and exert gentle pressure to ensure they stay in proper alignment.
Posterior Shin Splints
Posterior shin splints manifest as pain at the inner side of your leg where the soleus meets the tibia. The pain may be mild to severe. If it is severe, you may have an accompanying stress fracture in the tibia, so see a doctor. Otherwise, ice the area as soon as you are done running – this helps prevent inflammation. Keep your foot elevated while you apply the ice, and take an NSAID to help reduce the inflammation. Take several days off from running before you head back out for another run. Make sure you stretch properly before and after running to help prevent shin splints.
If you ignore your body’s warning signs and run despite pain or discomfort, or suddenly increase your mileage, you may experience a muscle strain. A calf strain is a partial or complete rupture of a muscle – in this case, the soleus muscle. Excessive hill training, ineffective warmups and cool-downs, and ignoring your body’s warning signs can lead to a muscle tear. Strains are divided into three levels of severity: grade one, where the muscle is irritated or inflamed, and can heal on its own if you allow it to rest; grade two, where there is a partial tear that needs rehabilitation and rest; and grade three, where there is a complete rupture of the muscle that requires surgery to repair. See your doctor if you experience a sharp or sudden pain, or your pain continues for several days, even after you give your legs a rest. Make sure you perform an adequate warmup and cool-down, and increase your mileage gradually to avoid injury.