• Where the clavicle comes together with the sternum is the only true bone to bone connection between the upper extremity and the trunk

• Also called collarbone

• Bone that connects the sternum to the scapula

• Connects medially to the sternoclavicular joint

• Connects laterally to the acromion of the scapula at the acromioclavicular joint

• Protects important nerves and blood vessels that are deep to it

  • Brachial plexus and subclavian artery and vein

• Located on the posterior side of the ribcage

• Forms part of the shoulder girdle

• Connects to the humerus and clavicle

• Provides attachment points for various muscles such as the rotator cuff muscles, serratus anterior, trapezius, and rhomboids

• Bone of the upper arm

• Proximal end articulates with the glenoid fossa of the scapula, forming the glenohumeral joint

• Provides attachment points for muscles that perform shoulder and elbow movements

•  Distal end articulates with the radius and ulna

Glenohumeral joint:

• Main shoulder joint

• Ball and socket joint where the head of the humerus fits into the glenoid fossa of the scapula

• Is stabilized by the muscles of the rotator cuff

• Shape allows for lots of actions such as flexion, extension, abduction, adduction, rotation, and circumduction

Acromioclavicular joint:

• Joint between acromion of the scapula and the clavicle

• Helps to move the scapula smoothly and efficiently in coordination with shoulder movement

Sternoclavicular joint:

• Joint between the sternum and clavicle

• Allows slight movement of the clavicle for more smooth and efficient shoulder movement

Scapulothoracic joint:

• Is where the scapula glides over the posterior rib cage

• Not a true synovial joint as there is no joint capsule, cartilage, or synovial fluid

• The scapula moves in coordination with the shoulder

  • General rule is for every 2 degrees of glenohumeral joint movement, there is 1 degree of scapulothoracic joint movement

    • During shoulder flexion and abduction beyond 30 degrees

  • This is called scapulohumeral rhythm