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    Related Topics

    From Musculoskeletal System

    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Radius
    Forearm bone on the thumb side.
    Biceps Brachii
    Muscle responsible for elbow flexion.
    Facial Bones
    Bones forming the structure of the face.
    Thoracic Cage
    Ribs and sternum forming the protective cage for the heart and lungs.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Occipital Bone
    Bone forming the back and base of the skull.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    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.
    Pectoralis Major
    Chest muscle responsible for shoulder movement.
    Adductors
    Muscles that bring the thighs toward the midline.
    Tarsals (7 bones)
    7 ankle bones.
    Acromioclavicular Joint
    The acromioclavicular joint connects the clavicle and scapula at the top of the shoulder, enabling smooth scapular motion and stability during arm movements.
    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.
    Medial Collateral Ligament (MCL)
    Knee ligament that stabilizes the inner knee.
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Ilium
    Uppermost and largest part of the hip bone.
    Brachioradialis
    Muscle responsible for forearm flexion.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Hinge Joints
    e.g., elbow, knee

    Anterior Longitudinal Ligament

    Reviewed by our medical team

    Spinal ligament running along the front of the vertebral column.

    1. Overview

    The Anterior Longitudinal Ligament (ALL) is a strong, broad ligament that runs along the anterior surface of the vertebral bodies in the spine. It plays a crucial role in maintaining vertebral alignment and limiting hyperextension of the vertebral column. The ALL is one of the primary stabilizing ligaments of the spine and extends from the base of the skull to the sacrum. Its integrity is essential for both static posture and dynamic spinal movements.

    2. Location

    The ALL is located along the anterior aspect of the vertebral column, specifically:

    • Superiorly: Begins at the anterior tubercle of the atlas (C1) and the basilar part of the occipital bone of the skull.

    • Inferiorly: Terminates at the anterior surface of the sacrum.

    • It runs continuously along the anterior surfaces of all vertebral bodies and intervertebral discs.

    3. Structure

    The ALL is a dense, fibrous ligament composed primarily of Type I collagen fibers, oriented longitudinally:

    • Width and thickness: It is broader and thicker in the thoracic region and narrower in the cervical and lumbar regions.

    • Attachment: Adheres strongly to the intervertebral discs and vertebral bodies, but less tightly to the periosteum of vertebrae.

    • Three layers:

      • Superficial layer: spans several vertebrae.

      • Intermediate layer: spans 2–3 vertebrae.

      • Deep layer: connects adjacent vertebrae only.

    This layered architecture allows the ALL to resist a range of mechanical stresses along the vertebral column.

    4. Function

    The Anterior Longitudinal Ligament provides multiple biomechanical functions:

    • Limits hyperextension: Prevents excessive backward bending of the spine.

    • Maintains anterior spinal stability: Supports alignment of vertebral bodies during motion and loading.

    • Distributes mechanical stress: Shares the axial load imposed on vertebral bodies and intervertebral discs.

    • Protects intervertebral discs: Limits forward bulging of discs during extension.

    5. Physiological role(s)

    The ALL plays a crucial role in spinal biomechanics and posture:

    • Supports upright posture: Prevents excessive lumbar lordosis or cervical extension while standing or walking.

    • Facilitates segmental motion control: Works with the posterior longitudinal ligament (PLL) to guide and restrict movement.

    • Integrates with spinal biomechanics: Contributes to the complex motion of flexion-extension, lateral bending, and rotation.

    • Assists in spinal proprioception: Contains sensory nerve fibers that contribute to position sense and postural reflexes.

    6. Clinical Significance

    The Anterior Longitudinal Ligament is involved in several spinal conditions and surgical procedures:

    • Hyperextension injuries:

      • Trauma such as whiplash can overstretch or rupture the ALL, leading to instability or anterior disc herniation.

    • Diffuse idiopathic skeletal hyperostosis (DISH):

      • A condition where the ALL becomes ossified, leading to stiffness, limited mobility, and sometimes dysphagia (if cervical spine is involved).

    • Anterior intervertebral disc herniation:

      • Though rare, disc material may protrude anteriorly, resisted or guided by the ALL.

    • Spinal surgery considerations:

      • May be dissected or mobilized during anterior spinal fusion or disc replacement procedures; damage must be minimized to preserve function.

    • Pain and inflammation:

      • Inflammatory conditions (e.g., spondyloarthritis) can affect the ALL and lead to anterior spinal pain or stiffness.

    Did you know? The ischium is the part of the pelvis you sit on.