Lecture on Shoulder Complex

Introduction

• Shoulder Complex Function: To place the hand in positions to perform various activities.
• Components: Involves structures of the axial and appendicular skeleton contributing to upper extremity movement.

Key Structures

• Sternum
• Rib Cage
• Clavicle
• Scapula
• Humerus

Primary Joints of the Shoulder Complex

1. Sternoclavicular (SC) Joint
2. Acromioclavicular (AC) Joint
3. Glenohumeral (GH) Joint
4. Scapulothoracic Articulation

Shoulder Girdle vs. Shoulder Joint

• Shoulder Girdle: Involves activities of the scapula, clavicle, sternum, and ribs.
• Shoulder Joint: Primarily refers to the glenohumeral joint.

Movements

• Shoulder Girdle Movements:

  • Elevation
  • Depression
  • Protraction (Scapular Abduction)
  • Retraction (Scapular Adduction)
  • Upward Rotation
  • Downward Rotation

• Shoulder Joint Movements:

  • Flexion
  • Extension
  • Abduction
  • Adduction
  • External Rotation
  • Internal Rotation
  • Horizontal Abduction
  • Horizontal Adduction

Glenohumeral Joint

• Structure: Involves glenoid cavity, humeral head, capsules, and ligaments.
• Type: Ball-and-socket joint.
• Stability: Relies on ligaments and muscles.
• Mobility: Most mobile joint, prone to dislocation.

Sternoclavicular (SC) Joint

• Type: Triaxial joint (movement in three planes).
• Ligaments:
  • Interclavicular ligament
  • Sternoclavicular ligament
  • Costoclavicular ligament
• Movements:
  • Clavicular elevation
  • Depression
  • Protraction
  • Retraction
  • Rotation

Acromioclavicular (AC) Joint

• Type: Triaxial joint
• Ligaments:
  • Acromioclavicular ligament
  • Coracoacromial ligament
  • Coracoclavicular ligament
• Injury: Susceptible to damage from falls, difficult to heal due to constant movement.

Scapulothoracic Articulation

• Description: Scapula moves along the rib cage (not a true joint).
• Movement: Combines scapular and clavicular movements.

Shoulder Girdle Movements (Detailed)

• Elevation: Moving shoulder upwards.
• Depression: Moving shoulder downwards.
• Protraction: Moving shoulder forward (scapular abduction).
• Retraction: Moving shoulder backward (scapular adduction).
• Upward Rotation: Glenoid cavity faces up.
• Downward Rotation: Glenoid cavity faces down.
• Scapular Tilt: Occurs during extreme shoulder extension or retraction.

Summary

• Focus on understanding the components, joints, and movements of the shoulder complex.
• Special attention to how the ligaments and muscles contribute to stability and mobility.