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    Related Topics

    From Musculoskeletal System

    Acetabulum
    The acetabulum is the pelvic socket that connects with the femoral head to form the hip joint, vital for stability, movement, and weight-bearing.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Gastrocnemius
    Calf muscle responsible for plantarflexion of the foot.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Hyoid Bone
    U-shaped bone in the neck that supports the tongue.
    Ilium
    Uppermost and largest part of the hip bone.
    Clavicle
    Collarbone connecting the arm to the body.
    Diaphragm
    Primary muscle for breathing.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Sternum
    Breastbone located in the center of the chest.
    Annular Ligament
    The annular ligament is a strong fibrous band encircling the head of the radius, stabilizing the proximal radioulnar joint and allowing smooth rotation of the forearm.
    Anterior Scalene Muscle
    The anterior scalene muscle is a deep neck muscle that elevates the first rib during inspiration and aids in neck flexion and stability, located between key neurovascular structures.
    Nasal Bones
    Bones forming the bridge of the nose.
    Buccinator
    Muscle that helps with chewing and blowing air out.
    Gomphoses
    Fibrous joints where a peg fits into a socket (e.g., teeth in jaw).
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.
    Occipital Bone
    Bone forming the back and base of the skull.
    Vomer Bone
    Bone forming the nasal septum.
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Ulna
    Forearm bone on the pinky side.
    Syndesmoses
    Fibrous joints where bones are connected by ligaments.
    Masseter
    Muscle that elevates the mandible.

    Coccygeus

    Reviewed by our medical team

    Pelvic floor muscle supporting the coccyx.

    1. Overview

    The coccygeus muscle, also known as the ischiococcygeus, is a small triangular muscle that forms part of the pelvic diaphragm. It is located posteriorly within the pelvis and works closely with the levator ani muscles to support the pelvic organs. Although relatively minor in size compared to other pelvic muscles, the coccygeus contributes to the structural integrity of the pelvic floor and assists in voluntary and reflexive functions related to posture and defecation.

    2. Location

    The coccygeus muscle is located in the posterior part of the pelvic floor:

    • Origin: Ischial spine of the hip bone.

    • Insertion: Lateral borders of the sacrum and coccyx (S5 to the coccygeal vertebrae).

    • Position: Lies posterior to the levator ani and anterior to the sacrospinous ligament, with which it blends closely.

    It forms the posterior portion of the pelvic diaphragm and bridges the gap between the sacrum and ischial spine.

    3. Structure

    The coccygeus is a flat, triangular, skeletal muscle with the following structural features:

    • Muscle fiber orientation: Directed superomedially from the ischial spine to the sacrum and coccyx.

    • Innervation: Branches of the anterior rami of spinal nerves S4 and S5.

    • Associated structures: The muscle is tightly associated with the sacrospinous ligament, often indistinguishable from it in dissection.

    • Blood supply: Inferior gluteal artery and branches from internal pudendal artery.

    4. Function

    The coccygeus muscle serves the following functions:

    • Supports pelvic viscera: Contributes to the structural integrity of the pelvic floor along with the levator ani.

    • Pulls coccyx forward: Assists in returning the coccyx to its normal position after defecation or childbirth.

    • Stabilizes the sacroiliac joint: Through its attachments and muscle tone, it supports pelvic alignment during movement.

    5. Physiological role(s)

    The coccygeus contributes to multiple physiological functions despite its small size:

    • Pelvic floor integrity: Acts with levator ani to support pelvic organs and prevent prolapse.

    • Continence mechanisms: Provides secondary support to the anal and urogenital sphincters during increased intra-abdominal pressure (e.g., coughing, lifting).

    • Defecation and childbirth: Assists in posterior movement of the coccyx to widen the pelvic outlet, then helps restore its position.

    • Postural role: Helps maintain upright posture by supporting pelvic tilt and pelvic base alignment.

    6. Clinical Significance

    Although less frequently discussed than other pelvic muscles, the coccygeus has several clinical considerations:

    • Coccygodynia (coccyx pain):

      • Strain or spasm of the coccygeus may contribute to tailbone pain, especially after trauma or prolonged sitting.

    • Pelvic floor dysfunction:

      • Weakness or imbalance involving the coccygeus can be part of broader pelvic floor disorders, including prolapse or fecal incontinence.

    • Postpartum changes:

      • The coccygeus may become overstretched or damaged during vaginal childbirth, contributing to postpartum pelvic pain.

    • Surgical relevance:

      • Understanding its location is important in sacrospinous ligament fixation procedures for pelvic organ prolapse repair.

    • Palpation and therapy:

      • Can be accessed through internal pelvic floor therapy techniques to manage chronic pelvic pain or myofascial dysfunction.

    Did you know? Your thumb has two phalanges, whereas other fingers have three.