GENERAL INFORMATION
The thigh soleus is a powerful muscle located in the posterior (back) part of the lower leg. It is one of the two primary muscles that make up the triceps surae, commonly known as the calf muscle. The soleus plays an important role in various movements, such as walking, running, and maintaining posture.
ORIGIN
The thigh soleus muscle originates from the posterior surface of the head, the upper third of the fibula (a bone in the lower leg), and the medial border of the tibia (the larger bone in the lower leg).
INSERTION POINT
The thigh soleus muscle merges with the gastrocnemius muscle to form the Achilles tendon, which inserts into the calcaneus (heel bone). The Achilles tendon is the largest and strongest tendon in the human body.
MAJOR ARTERIES
The thigh soleus muscle receives its blood supply primarily from the following arteries:
- Posterior tibial artery
- Peroneal artery
NEURAL INNERVATION
The thigh soleus muscle is innervated by the tibial nerve, which arises from the sciatic nerve. The tibial nerve provides motor innervation to the soleus, allowing it to contract and produce movement.
TRIGGER POINT
A common trigger point in the thigh soleus muscle is located in the belly of the muscle. Trigger points in this area can cause pain and tightness, often radiating into the foot or up the back of the leg.
CONCENTRIC FUNCTION
The concentric function of the thigh soleus muscle involves the shortening or contraction of the muscle. It is primarily responsible for plantar flexion of the foot, which consists in pointing the foot downward.
ECCENTRIC FUNCTION
The eccentric function of the soleus refers to the controlled lengthening of the muscle while resisting an external force. It is involved in movements such as lowering the heel from a raised position or decelerating the foot during landing.
ISOMETRIC FUNCTION
The isometric function of the thigh soleus muscle involves contracting the muscle without any change in length. Isometric contractions of the calf muscles occur during activities like standing or maintaining balance.
RELATED MUSCLE SCIENTIFIC NAMES
- Soleus muscle (Musculus soleus)
ANTAGONIST
The antagonist muscle to the thigh soleus is the tibialis anterior, which is responsible for dorsiflexion of the foot (bringing the foot upward).
COMMON INJURIES
- Soleus strain: Overstretching or tearing of the soleus muscle due to sudden movements or excessive physical activity.
- Achilles tendonitis: Inflammation of the Achilles tendon, often caused by repetitive stress or overuse.
- Calf cramps: Painful involuntary contractions of the calf muscles, typically caused by dehydration or muscle fatigue.
EXERCISES
- Calf raises: Standing on the edge of a step or platform and raising the heels to work the soleus muscle.
- Seated calf raises: Sitting on a chair or bench with knees bent and feet flat on the floor, then lifting the heels to target the soleus muscle.
- Leg press: A leg press machine is used to perform calf presses, targeting both the gastrocnemius and soleus muscles.
STRETCHES
- Standing calf stretch: Placing the hands against a wall, one leg is extended behind while keeping the heel on the ground, stretching the soleus muscle.
- Seated calf stretch: Sitting with legs extended, a strap or towel wrapped around the foot, and gently pulling the toes towards the body to stretch the soleus muscle.
- Downward-facing dog pose: A yoga pose that stretches the entire posterior chain, including the soleus muscle.