Synovial Joint Movements

Muscle Action and Attachments

• Muscle Attachments: Muscles attach to bones or connective tissues at no fewer than two points.
  • Origin: Attachment that doesn't move during muscle contraction.
  • Insertion: Attachment that moves during muscle contraction.
• Example:
  • Biceps muscle on the upper arm:
    • Origin: Upper arm
    • Insertion: Forearm

Joint Movements

• Movement occurs in specific planes: transverse, frontal, or sagittal.
• Movements categorized by axes:
  • Non-axial: Slipping movements.
  • Uniaxial: Movement in one plane.
  • Biaxial: Movement in two planes.
  • Multi-axial: Movement in all three planes (e.g., shoulder joint).

Types of Movements

1. Gliding Movements

• Description: Flat bone surfaces glide over another surface.
• Examples: Intercarpal joints of wrists, ankle joints, articular processes of vertebrae.

2. Angular Movements

• Description: Change in angle between two bones.
• Includes: Flexion, extension, hyperextension, abduction, adduction, circumduction.

Flexion and Extension

• Flexion: Decreases the angle of a joint.
• Extension: Increases the angle of a joint.
• Hyperextension: Beyond normal anatomical position.
• Examples: Neck, trunk, arms, legs.

Abduction and Adduction

• Abduction: Movement away from midline.
• Adduction: Movement towards midline.
• Examples: Raising/lowering arms or legs.

Circumduction

• Description: Limb describes a cone in space, involving flexion, abduction, extension, and adduction.

3. Rotational Movements

• Description: Turning of a bone around its own axis.
• Types:
  • Medial Rotation: Toward midline.
  • Lateral Rotation: Away from midline.
• Examples: Vertebrae, humerus, femur.

Special Movements

Supination and Pronation

• Supination: Palm faces anteriorly.
• Pronation: Palm faces posteriorly.

Dorsiflexion and Plantar Flexion

• Dorsiflexion: Pointing toes upward.
• Plantar Flexion: Pointing toes downward.

Inversion and Eversion

• Inversion: Sole of the foot faces medially.
• Eversion: Sole of the foot faces laterally.

Protraction and Retraction

• Protraction: Movement of body part anteriorly.
• Retraction: Movement of body part posteriorly.

Elevation and Depression

• Elevation: Raising a body part.
• Depression: Lowering a body part.

Opposition

• Description: Touching fingers or toes together.
• Examples: Thumb connecting with fingers.