8.4

Module 8.4: Movements and Anatomical Terms

Overview

  • In understanding body movements, specific terms are utilized in reference to the anatomical position.
  • Familiarity with these descriptive terms is essential as they will be used in detailing the functions of joints and muscle actions.
  • Red dots in illustrations indicate joint locations involved in demonstrated movements.

Key Terms in Movement

Flexion and Extension

  • Flexion:

    • Definition: Movement in the anterior-posterior (sagittal) plane that decreases the angle between articulating bones.
    • Examples: Flexion occurs at the neck, elbow, and hip. When you bring your head toward your chest, you flex the intervertebral joints of the neck.

  • Extension:

    • Definition: Movement that increases the angle between articulating bones, occurring in the same plane as flexion.
    • Anatomical Position: In the anatomical position, all major joints (except the ankle) are at full extension.

  • Hyperextension:

    • Definition: Further extension of a limb or body part past the anatomical position.

Dorsiflexion and Plantar Flexion

  • Dorsiflexion:

    • Definition: Upward movement of the foot or toes, as in digging in your heel.

  • Plantar Flexion:

    • Definition: Extends the ankle joint and bends the foot/toes downward, as when standing on tiptoe.
    • Note: It's simpler to refer to these as "flexion and extension at the ankle," rather than specifying dorsiflexion and plantar flexion.

Lateral Flexion

  • Lateral Flexion:
    • Definition: This occurs when the vertebral column bends to the side, most pronounced in the cervical and thoracic regions.

REVIEW Questions

  • A. Which movements are possible at hinge joints?
  • B. Compare dorsiflexion to plantar flexion.

Module 8.5: Rotation and Special Movements

Overview

  • Specific terms are designated for describing rotation and other types of specialized movements.

Rotation

  • Types of Rotation:
    • Right or Left Rotation: Generally refers to the head and trunk.
    • Medial and Lateral Rotation: Refers to limb rotation.
    • Medial Rotation (Internal): Anterior surface of a limb turns toward the midline of the body.
    • Lateral Rotation (External): The reverse of medial rotation.

Special Terms for Forearm Rotation

  • Pronaton:

    • Definition: Turns the wrist and hand from the palm-facing front to back. Occurs at the proximal radio-ulnar joint.

  • Supination:

    • Definition: The movement that turns the palm anteriorly. Also occurs at the proximal radio-ulnar joint.

Special Movements

  • Opposition:

    • Definition: Movement of the thumb towards the palm or pads of other fingers, allowing grasping objects. Involves movements at the first carpometacarpal and metacarpophalangeal joints.

  • Protraction and Retraction:

    • Protraction: Movement of a body part anteriorly in the horizontal plane (e.g., protruding the jaw).
    • Retraction: The reverse movement of protraction (e.g., returning the jaw to normal position).

  • Inversion and Eversion:

    • Inversion: Twisting motion of the foot that turns the sole inward, elevating the medial edge of the sole.
    • Eversion: The opposite movement, turning the sole outward.

  • Elevation and Depression:

    • Elevation: Lifting a body structure superiorly (e.g., closing the mouth).
    • Depression: Moving a body part inferiorly (e.g., opening the mouth).

REVIEW Questions

  • A. What movements are made possible by the rotation of the head of the radius?
  • B. Snapping your fingers involves what movement of the thumb?
  • C. What hand movements occur when a person wriggles into tight-fitting gloves?

Learning Outcomes

  • Describe flexion/extension, abduction/adduction, circumduction, rotational, and special movements of the skeleton.