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    Related Topics

    From Musculoskeletal System

    Facial Bones
    Bones forming the structure of the face.
    Gluteus Maximus
    Largest muscle in the buttocks responsible for hip extension.
    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    Saddle Joints
    e.g., thumb joint
    Ball-and-Socket Joints
    e.g., shoulder, hip
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.
    Gliding (Plane) Joints
    e.g., between carpals
    Phalanges (14 bones)
    14 bones forming the toes.
    Cranial Bones
    Bones of the skull that protect the brain.
    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.
    Mandible
    Lower jawbone that houses the teeth.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Anterior Cruciate Ligament (ACL)
    Knee ligament that stabilizes the joint.
    Radius
    Forearm bone on the thumb side.
    Ligamentum Flavum
    Spinal ligament connecting the laminae of adjacent vertebrae.
    Carpals (8 bones)
    8 wrist bones.
    Sternum
    Breastbone located in the center of the chest.
    Wormian Bones
    Sutural bones in the skull.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Ethmoid Bone
    Bone forming part of the nasal cavity and the orbit.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.

    Ellipsoidal (Condyloid) Joints

    Reviewed by our medical team

    e.g., wrist

    1. Overview

    An ellipsoidal joint, also known as a condyloid joint, is a type of synovial joint that permits movement in two planes: flexion–extension and abduction–adduction. These biaxial joints have an oval-shaped condyle of one bone fitting into the elliptical cavity of another, allowing angular but not rotational movement. Ellipsoidal joints are essential for precise, controlled motion and are found in areas requiring coordinated mobility and stability.

    2. Location

    Ellipsoidal joints are present in several key areas of the body:

    • Wrist joint (radiocarpal joint): Between the distal radius and the scaphoid and lunate carpal bones.

    • Metacarpophalangeal joints (MCPs): Between the heads of metacarpal bones and bases of proximal phalanges in the fingers (knuckle joints).

    • Atlanto-occipital joint: Between the occipital condyles of the skull and the superior facets of the atlas (C1 vertebra).

    • Metatarsophalangeal joints (MTPs): Similar joints in the toes.

    3. Structure

    Ellipsoidal joints are structured for complex movement within a confined range:

    • Articular surfaces: One surface is an oval convex condyle, and the other is a reciprocally shaped concave surface.

    • Joint capsule: Encloses the joint and is lined by a synovial membrane that secretes synovial fluid.

    • Synovial fluid: Lubricates the joint, reduces friction, and nourishes articular cartilage.

    • Ligaments: Surround and stabilize the joint, preventing excessive or abnormal movement.

    • Articular cartilage: Covers the joint surfaces, allowing smooth, low-friction interaction between bones.

    4. Function

    Ellipsoidal joints allow a range of controlled, angular motions:

    • Flexion and extension: Movement in the sagittal plane, such as bending and straightening fingers.

    • Abduction and adduction: Movement in the coronal plane, such as spreading fingers apart or bringing them together.

    • Circumduction: A circular, conical motion combining flexion, extension, abduction, and adduction (but no axial rotation).

    5. Physiological role(s)

    Ellipsoidal joints play crucial roles in fine and gross motor function:

    • Manual dexterity: MCP joints are key to grasping, pinching, and manipulating objects with precision.

    • Postural alignment: Atlanto-occipital joint helps support head posture and balance.

    • Locomotion support: MTP joints contribute to propulsion and toe-off during walking and running.

    • Articulation balance: These joints enable complex joint interplay without compromising stability.

    6. Clinical Significance

    Several conditions can affect ellipsoidal joints and impair their function:

    • Osteoarthritis:

      • Degeneration of articular cartilage in MCP or wrist joints causes stiffness, pain, and loss of function.

    • Rheumatoid arthritis:

      • Commonly affects MCP joints with joint swelling, deformity (e.g., ulnar drift), and inflammation.

    • Atlanto-occipital dislocation:

      • A rare but life-threatening injury where the skull becomes dislodged from the spine, often due to trauma.

    • Joint contracture or stiffness:

      • Prolonged immobility or scarring may limit movement at ellipsoidal joints, particularly in the fingers.

    • Joint injections or aspiration:

      • Inflamed or swollen ellipsoidal joints, especially the wrist, may require corticosteroid injections or fluid removal for relief.

    Did you know? The human body has over 600 muscles.