Section 01 of 20
Introduction
Soleus is a broad, flat muscle in the back of the lower leg, lying deep to the two-headed gastrocnemius. Unlike gastrocnemius, it crosses only the ankle joint, not the knee, so it plantar flexes the foot regardless of whether the knee is bent or straight.
Soleus and gastrocnemius share a common tendon, the Achilles (calcaneal) tendon, which attaches to the heel. Because soleus is made mostly of slow-twitch fibers, it is especially important for sustained standing posture and is often called part of the body's "second heart," since its rhythmic contraction helps pump venous blood back up the leg.
Section 02 of 20
Origin
| Origin | The posterior surface of the head and upper shaft of the fibula, the soleal line and middle third of the medial border of the tibia, and a tendinous arch (the soleal arch) between the tibia and fibula. |
|---|
An anatomical image for this section will be added when verified source media becomes available.
Section 03 of 20
Insertion
| Insertion | The posterior surface of the calcaneus, through the Achilles tendon, shared with gastrocnemius. |
|---|
An anatomical image for this section will be added when verified source media becomes available.
Section 04 of 20
Actions
| Primary action | Plantar flexion of the ankle. |
|---|---|
| Secondary actions | Postural stabilization at the ankle and support for venous return. |
| Movement at the joint | Ankle (talocrural) joint only. |
| Heads / fiber groups | Single broad muscle, deep to gastrocnemius. |
| Functional examples | Standing; walking and running; rising onto the toes; cycling and squatting (knee-bent plantar flexion). |
Plantar flexion of the ankle
Points the foot downward, regardless of knee position.
Postural stabilization
Controls forward sway of the leg over the foot during standing (steadying the body at the ankle).
Venous return support
Its rhythmic contraction during walking and standing helps pump blood from the legs back toward the heart.
Section 05 of 20
Nerve Innervation
| Nerve | Tibial nerve, roots S1–S2. |
|---|
The tibial nerve and the posterior tibial vessels run along the deep side of the calf near soleus. Numbness in the sole of the foot, calf swelling, or a sense of heaviness may reflect nerve or vascular problems, not only muscle tightness.
Section 06 of 20
Blood Supply
| Blood | The posterior tibial artery and the fibular (peroneal) artery. |
|---|
Section 07 of 20
Pictures and Visual Anatomy
An anatomical image for this section will be added when verified source media becomes available.
Section 08 of 20
Functional Movement
Soleus is used in standing, walking, running, and rising onto the toes, and it works especially hard when the knee is bent, such as when squatting or cycling, since gastrocnemius is less effective in that position. It is also constantly active in quiet standing to prevent forward toppling.
Section 09 of 20
Synergists and Antagonists
Synergists: gastrocnemius (plantar flexion) and, to a lesser extent, tibialis posterior, flexor hallucis longus, and flexor digitorum longus. Antagonists: tibialis anterior and the other ankle dorsiflexors.
Section 10 of 20
Palpation and Location
Client position and technique
Position the client prone with the foot hanging relaxed off the end of the table, or with the knee bent to relax gastrocnemius. Locate the sides of the calf below the two bellies of gastrocnemius, where soleus is broader and can be felt on both the medial and lateral sides. Ask the client to plantar flex the ankle with the knee bent to feel soleus contract with less involvement of gastrocnemius.
Protect nearby structures
The posterior tibial vessels, the tibial nerve, and the deep veins of the calf lie close to and within the muscle. Use moderate pressure, avoid pressing sharply into the deep calf, and never massage a calf that is unexplainably swollen, warm, red, or painful. Stop if the client reports tingling, numbness, or sharp pain.
Section 11 of 20
Massage Therapy Relevance
Soleus is commonly tight in people who wear heeled shoes, sit for long periods, or run and walk frequently. Its deep location and role in venous return make careful screening for blood clots especially important before working on the calf.
Section 12 of 20
Dysfunction: What Happens When Movement Goes Wrong
Changes in how a muscle works can change how a joint moves. The points below describe possibilities that may be associated with altered muscle function; they are not diagnoses, and one muscle is never assumed to be the sole cause of a problem.
When the muscle is weak
Weakness may reduce push-off strength and standing endurance and may be associated with more sway and reliance on other calf muscles.
When it is tight or shortened
Tightness may be associated with limited ankle dorsiflexion with the knee bent and a feeling of a short, stiff calf.
When it is overused
Prolonged standing, running, and repeated calf raises may overload the muscle and its tendon and may contribute to deep calf or Achilles-region pain.
When it is strained
A strain may cause a deep calf ache with loading, especially with the knee bent; a blood clot and gastrocnemius strain can look similar.
When it is inhibited or others compensate
Reduced activation may be associated with poor standing balance and more work by gastrocnemius and the other lower leg muscles.
When it does not coordinate well with synergists and antagonists
Poor coordination with gastrocnemius and the other ankle muscles may alter push-off and balance and may be associated with calf or ankle symptoms.
Section 13 of 20
Conditions, Pathologies, and Pain Relationships
Soleus strain
Overuse or sudden loading, especially with the knee bent (such as running uphill or cycling), can strain the muscle and cause a deep calf ache.
Calf tightness and cramping
A short, tight soleus may be associated with limited ankle dorsiflexion with the knee bent and may contribute to calf cramps.
Achilles tendinopathy
Because soleus shares the Achilles tendon with gastrocnemius, overload of either muscle may be associated with tendon pain near the heel.
Differential considerations
Deep vein thrombosis, chronic venous insufficiency, gastrocnemius strain, and nerve entrapment can all cause calf pain or swelling and must be distinguished from muscular calf tightness.
Section 14 of 20
Example Clinical Relationship
A client who wears heeled shoes for most of the day reports a persistent tight, achy feeling deep in the calf and stiffness when trying to squat flat-footed. Soleus may be shortened, and the pattern may be associated with tightness from habitual heel wear, but a blood clot, Achilles tendon problems, and nerve entrapment can look similar. Gentle work on the sides of the calf may support comfort, while a swollen warm calf, a sudden snap with severe pain, or a cold numb foot needs referral.
Section 15 of 20
Massage and Treatment Approaches
For healthy, non-acute tissue, position the client prone with the knee slightly bent and the foot supported. Begin with light effleurage from the ankle toward the knee, then use gentle kneading of the sides of the calf below the gastrocnemius bellies, working within comfortable pressure.
| Movement | Use gentle ankle dorsiflexion stretches with the knee bent within comfort; do not force range. |
|---|---|
| Regional work | Consider gastrocnemius, the Achilles tendon area, tibialis posterior, and the plantar fascia when assessment supports it. |
| Avoid | Deep pressure into the deepest part of the calf, over a swollen or discolored calf, or at any point that reproduces sharp pain or numbness. |
Section 16 of 20
Precautions and Contraindications
Precautions and contraindications
- A swollen, warm, red, or painful calf, or known or suspected blood clot: do not massage, and refer.
- Recent calf, ankle, or Achilles injury or surgery.
- Use caution with varicose veins, chronic venous insufficiency, anticoagulant use, or easy bruising.
- Stop if pressure causes sharp pain, tingling, or numbness.
Section 17 of 20
Red Flags and When to Refer
Red flags and referral
- A swollen, warm, red, or painful calf, especially on one side, or sudden shortness of breath or chest pain (possible blood clot).
- A sudden snap with severe calf pain, swelling, and bruising, or inability to rise onto the toes (possible tendon rupture).
- A cold, pale, or numb foot, or loss of pulse.
- Calf pain with fever, or after a long flight, surgery, or period of immobility.
Section 18 of 20
Study Summary
Attachments
Origin: posterior fibula, soleal line of the tibia, and the soleal arch. Insertion: calcaneus, via the Achilles tendon.
Actions
Plantar flexes the ankle; supports posture and venous return.
Supply
Tibial nerve (S1–S2); posterior tibial and fibular arteries.
Section 19 of 20
Instructor Narration
Open narration transcript
Soleus is the broad, flat calf muscle beneath the gastrocnemius. It crosses only the ankle, not the knee.
It arises from the back of the fibula, the soleal line of the tibia, and the soleal arch between them, and inserts on the calcaneus through the Achilles tendon, shared with gastrocnemius.
It plantar flexes the ankle in any knee position, helps control forward sway in standing, and helps pump venous blood back up the leg. Gastrocnemius helps it, and the ankle dorsiflexors oppose it.
The tibial nerve supplies it, from S1 to S2, and the posterior tibial and fibular arteries provide its blood.
Palpate with the knee bent to relax gastrocnemius, and feel the broader soleus on the sides of the calf below the gastrocnemius bellies. Avoid pressing deeply into the calf, and never work on a swollen, warm, or painful calf.
Strain, tightness, cramping, and Achilles tendon problems are common, and a blood clot can mimic a calf strain. Refer a swollen warm calf, a sudden snap with severe pain and bruising, a cold or numb foot, or calf pain with fever or after a long flight or surgery.
Remember: fibula and soleal line of the tibia to the calcaneus via the Achilles tendon; plantar flexion regardless of knee position; tibial nerve.
Section 20 of 20