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    Related Topics

    From Musculoskeletal System

    Vertebral Column
    Spinal column consisting of vertebrae.
    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Saddle Joints
    e.g., thumb joint
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Pectoralis Major
    Chest muscle responsible for shoulder movement.
    Flexor Tendons
    Tendons that help flex the fingers and toes.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Pivot Joints
    e.g., atlanto-axial joint
    Wormian Bones
    Sutural bones in the skull.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Adductors
    Muscles that bring the thighs toward the midline.
    Quadriceps
    Rectus Femoris, Vastus Medialis, Vastus Lateralis, Vastus Intermedius.
    Pelvic Floor Muscles
    Muscles that support pelvic organs.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Hamstrings
    Biceps Femoris, Semitendinosus, Semimembranosus.
    Ligamentum Flavum
    Spinal ligament connecting the laminae of adjacent vertebrae.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Masseter
    Muscle that elevates the mandible.
    Femur
    Thigh bone, the longest and strongest bone in the body.
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.
    Nasal Bones
    Bones forming the bridge of the nose.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Skull
    Bony structure of the head that encases the brain.

    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? Sesamoid bones are bones that form within tendons, like the patella.