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    Related Topics

    From Musculoskeletal System

    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.
    Quadriceps Tendon
    Tendon that connects the quadriceps to the patella.
    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Coccyx
    Tailbone, the remnant of the tail in humans.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Ulna
    Forearm bone on the pinky side.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.
    Mandible
    Lower jawbone that houses the teeth.
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Fibula
    Smaller bone in the lower leg, located alongside the tibia.
    Temporalis
    Muscle involved in closing the jaw.
    Pivot Joints
    e.g., atlanto-axial joint
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    Nasal Bones
    Bones forming the bridge of the nose.
    Phalanges (14 bones)
    14 bones forming the toes.
    Radius
    Forearm bone on the thumb side.
    Masseter
    Muscle that elevates the mandible.
    Ligamentum Flavum
    Spinal ligament connecting the laminae of adjacent vertebrae.
    Acromioclavicular Ligament
    Ligament that connects the acromion to the clavicle.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Rectus Abdominis
    Abs muscle that flexes the trunk.

    Soleus

    Reviewed by our medical team

    Calf muscle responsible for plantarflexion of the foot.

    1. Overview

    The soleus is a broad, powerful muscle located in the posterior compartment of the leg. It lies deep to the gastrocnemius muscle and, along with it, forms the calf. The soleus plays a key role in plantarflexion of the foot at the ankle joint and is essential for posture, balance, and locomotion, especially during standing and walking.

    2. Location

    The soleus is located in the posterior (superficial) compartment of the leg:

    • Proximally: Originates from the posterior surface of the tibia and fibula.

    • Distally: Joins with the gastrocnemius to insert via the calcaneal (Achilles) tendon onto the calcaneus (heel bone).

    • Deep to: The gastrocnemius muscle.

    3. Structure

    The soleus is a flat, multipennate muscle with a broad origin:

    • Origin:

      • Posterior surface of the proximal tibia (soleal line).

      • Head and upper third of the fibula.

      • Interosseous membrane between the tibia and fibula.

    • Insertion: Posterior surface of the calcaneus via the common Achilles tendon.

    • Innervation: Tibial nerve (S1–S2).

    • Blood supply: Branches from the posterior tibial artery and peroneal artery.

    4. Function

    The soleus is a key contributor to movement and stability:

    • Plantarflexion: Extends the foot downward at the ankle joint, especially during slow or sustained movement (e.g., standing, walking uphill).

    • Postural support: Prevents the body from falling forward by counteracting gravity during standing.

    • Supports venous return: Acts as a "muscle pump" to aid blood return from the lower limbs to the heart.

    5. Physiological role(s)

    Beyond movement, the soleus plays vital roles in systemic function:

    • Maintains upright posture: Constantly active in quiet standing to resist forward sway.

    • Endurance muscle: Rich in slow-twitch (type I) muscle fibers, making it highly fatigue-resistant and suited for long-term, low-intensity activity.

    • Assists in gait: Works with the gastrocnemius to propel the body forward during the push-off phase of walking and running.

    • Circulatory support: Helps prevent venous pooling in the lower limbs, reducing risk of edema and deep vein thrombosis (DVT).

    6. Clinical Significance

    The soleus muscle is involved in several musculoskeletal and vascular conditions:

    • Calf strain or "tennis leg":

      • Injury may involve the soleus, particularly in athletes or individuals performing repetitive movements.

    • Achilles tendinopathy:

      • Chronic stress from the soleus can contribute to inflammation or degeneration of the Achilles tendon.

    • Compartment syndrome:

      • Swelling of the soleus within the posterior compartment may increase pressure and compromise blood flow, requiring emergency treatment.

    • Venous thromboembolism (VTE):

      • Immobility can impair the soleus pump, increasing risk of deep vein thrombosis, particularly in hospitalized or sedentary patients.

    • Rehabilitation importance:

      • Often targeted in strengthening and stretching programs for conditions like plantar fasciitis, flat feet, and Achilles injuries.

    Did you know? Your bones are constantly being broken down and rebuilt — you have a new skeleton every 10 years.