I think of the soleus as the unsung hero of the calf complex. If a bodybuilder shows off his/her calves, they will try to get into a position where the gastrocnemius muscles are shown off. The gastrocs are the bulgy muscles higher up on the lower leg. The poor soleus muscle somehow gets ignored, and yet it plays a vital role.
The only way for the muscle to get recognition is for it to start hurting. The muscle extends from the top of the tibia to the Achilles tendon. It is visible on the lower leg and is then hidden by the gastroc muscle, (much like Kanye and the Kardashians).
The soleus is the wide, flat muscle that covers and shapes the calf region of the lower leg. The muscle often forms trigger points that cause heel pain in runners during and after exercise. It can also (along with the tibialis posterior trigger point) produce pain the Achilles tendon region. Other trigger points in the soleus produce pain and tenderness in the calf region and rarely even way up in the sacroiliac joint of the low back region.
The soleus acts as a “second heart” pumping venous blood from the legs back upwards. Trigger points can hinder this action and therefore lead to swelling in the lower leg.
The muscle helps you raise your heel during the toe off phase of your walk, run or bike ride. This downward pushing of the foot is known as plantar flexion.
It also provides ankle stability as your foot lands while you walk or run. This is important for pronators to take note of, as the muscle can get injured if your shoe is not stable enough.
The muscle, under specific conditions, can also help with inversion of the foot. Inversion means the pulling toward your midline of the foot.
The muscle does not cross the knee joint, unlike its neighbor, the gastrocnemius. It is attached to the head of the fibula and the posterior and medial aspects of the tibia. The illustration below should bring some clarity regarding the last sentence.
The muscle attaches to the Achilles tendon, which in turn attaches to your heel bone or calcaneus.
The muscle contains a structure known as the soleus bridge. Two sheets of fascia are formed around a series of blood vessels and nerves.
The soleus works together with a few other muscles such as the gastrocnemius, tibialis posterior and fibularis muscles. If the soleus gets itself trigger pointed, extra work will be required of its two neighbors.
The muscle can typically develop trigger points in three areas.
1. At the point of connection with the Achilles. It’s this trigger point that can radiate pain down into the heel.
2. Then on the midsection on the lateral side and toward the top of the muscle. The top trigger point can radiate pain up into the sacroiliac area.
How to injure the muscle, (not that you want to).
Running – especially uphill
Training on beach sand – I saw a few of these after the December holidays.
Wearing stiff shoes that cause the calf to overwork.
Sleeping for prolonged periods on your stomach. This will cause your feet to point down, hence shortening the calf muscles.
Shortened calf muscles and calf muscles with trigger points will place more strain on the Achilles tendon. This can over time damage the tendon. It is always easier to treat a strained muscle than a tendonitis. Runners and cyclists typically report pain at the onset of exercise that dissipates during exercise, and then comes back as you stop exercising.
Calf pain can also be caused by a deep vein thrombosis. This constitutes a medical emergency and so you need to get to your doctor or casualty unit to get it checked out. Redness of the skin and swelling in the area must be taken seriously.
We always check your rate of pronation when we sell running shoes. The muscle is also carefully palpated during our Runner’s Leg Assessments.
Hope that this was helpful and that your soleus has a smile on it.