Lecture 29 - Joints: Movement

Chapter 8 - Joints & Movements

Types of Movements @ Synovial Joints

  • Joint structure determines movements

4 Main Types of Movements:

  1. Gliding

  2. Angular

  3. Circular

  4. “Special Movements” (Many different movements, only in one or two places in the body)


Gliding Movements

  • @ Plane Joints

    • 2 smooth, flat surfaces coming together

  • In many different directions, most often limited by connective tissue (ligaments)

  • Gliding movements - increased dexterity of the hand

  • Gliding joints between inferior & superior articular process of vertebrae

    • Where vertebrae form joint w/ each other

    • Not intervertebral disks

Angular Movements

  • One part of linear structure is bent relative to another part of the structure creating the angle

  1. Flexion/Extension

    • Flexion - Bend/decrease the angle

    • Extension - Straighten/increase angle

      • Eg. Hinge Joint of elbow

    • Flexion = Movement in anterior direction

    • Extension = Movement in posterior direction

    • Hyperextension = extension beyond anatomical position

      • Eg. Elbow, Arm @ Shoulder, Leg @ hip, Trunk, Head @ Neck

    • Exceptions: Knee and lateral flexion (anterior/posterior definition does not apply)

  2. Plantar Flexion & Dorsiflexion

    • Specific to the ankle joint

    • Plantar flexion - Movement toward plantar surface of foot

    • Dorsiflexion - movement away from plantar surface of foot

  3. Abduction & Adduction

    • Relative to midline of body/structure of body

    • Abduction = Movement away from midline

    • Adduction = Movement towards midline

    • Can be applied to the whole body, or the movement of structures that can be divided in half (Eg. Fingers of Hand - middle finger = center/midline of hand)

    • Specific Terms for Hands - From Anatomical Position

      • Abduction (Movement of hand away from body) = Radial Deviation

        • Thumb towards radial bone

      • Adduction (Movement of hand towards body) = Ulnar Deviation

        • Pinky towards ulna

Circular Movements

  1. Rotation

    • Turning of a structure around its long axis

    • Rotating the Humerus or Femur within the ball & socket joint

    • Eg. Humerus - Flexing forearm

      • Medial Rotation - Rotation towards body

      • Lateral Rotation - Rotation away from body

    • Eg. Hip Joint - Rotation of leg medially & laterally

    • Eg. Atlanto-Axial Joint

      • C1 rotates around dens of C2

  2. Pronation & Supination

    • Specific to forearm

    • Rotation of forearm

    • Rotation of the head of the radius against the proximal end of the ulna

      • Notch @ end of ulna (Radial notch)

      • Head of Radius rotates against ulna in pivot joint

    • Pronation - From anatomical positon, rotating forearm so that palm is facing backwards

      • When palm of hand is facing posteriorly, radius is rotated over top of ulna

    • Supination - Forearm is flat, palm facing upwards

      • Bones parallel, radius is not crossed over ulna

  3. Circumduction

    • Combination of flexion, extension, adduction, abduction

    • Creates a circle/arc

    • Ball & socket joints

      • Hip & shoulder

    • Fingers

    • Head relative to neck

Special Movements

  • Specific to one or two joints in body, do not specifically fit into one of the other categories

  1. Depression & Elevation

    • Scapula & Mandible

    • Elevation = Moves structure superiorly

    • Depression = Moves structure inferiorly

  2. Protraction & Retraction

    • Mandible, Clavicle, Scapula

    • Protraction - Anterior movement in transverse plane

    • Retraction - Posterior movement in transverse plane

    • Eg. Mandible

      • Moving Mandible forward = Protraction

      • Moving Mandible Backward = Retraction

    • Eg. Clavicle & Scapula

      • Hunch shoulders forward = Clavicle & scapula → protraction

      • Square shoulders/bring them back = Scapula move towards each other → Retraction

  3. Opposition & Reposition

    • Specific to movement of hand

    • Opposition = Thumb & little finger brought together

    • Reposition = Return back to neutral

    • Allows us to have opposable thumbs

      • Specific to humans and primates

      • Gives manual dexterity

  4. Inversion & Eversion (Intertarsal)

    • Specific to smaller subtalar joint or intertarsal joints

    • Multiple movements between bones allows for specific movement

    • Inversion = Turning Ankle - Plantar surfaces faces medially

    • Eversion = Turning ankle, plantar surface faces laterally