Considered a bone of both shoulder girdle and shoulder joint. The shoulder girdle is comprised of the clavicle and the scapula. The shoulder joint consists of the scapula and the humerus. The primary function of the shoulder girdle is to position itself to accommodate movements of the shoulder joint.

1 Superior angle—top point Inferior angle—bottom point Vertebral border—side closest to vertebral column Axillary border—side closest to arm Subscapular fossa—anterior fossa Glenoid fossa, glenoid labrum, glenoid cavity --The glenoid fossa is the shallow cavity where the humeral head goes. The glenoid labrum is the cartilage that goes around the glenoid fossa. So the glenoid fossa and glenoid labrum together comprise the glenoid cavity. Supraspinous fossa—posterior, fossa above the spine Spine of the scapula—the back projection Infraspinous fossa—posterior depression/fossa below spine Coracoid process—anterior projection head Acromion process—posterior projection head above spine

2 Scapulothoracic “joint” = NOT a true joint; there are no ligaments or articular capsule. The scapula just rests on the muscle over top the rib cage, which allows for passive movements. Sternoclavicular joint=where the clavicle (collarbone) and the sternum (breastbone) articulate; movement is slight in all directions and of a gliding, rotational type Acromioclavicular joint = where the clavicle and scapula (acromion process) articulate; AKA: AC Joint; movement is a slight gliding when elevation and depression take place. Glenohumeral joint = the shoulder joint

3 4 All 3 true joints: Sternoclavicular, AC and glenohumeral (GH) all work together to move arm in all directions. The GH allows the arm to go out to the side and be abducted, then the AC and Sternoclavicular joints kick in to allow the arm to go above shoulder level by allowing the shoulderblade to move up to increase the range of motion (ROM).

The clavicle helps increase the ROM because it acts as a strut maintaining the upper limb away from the thorax, which allows the greater ROM to occur.

5 Acromioclavicular ligament—functions as the joint capsule by tying together and totally surrounding the lateral end of the clavicle and the acromion process (scapula) Sternoclavicular ligament—has anterior, superior, and posterior fibers to help with the SC articulation

6 Click on the hyperlink to see a shoulder injury. A shoulder dislocation is when the humerus head comes completely out of the GH joint—the ball comes out of the socket. This usually will occur when the arm is abducted and in shoulder flexion (arm raised up). Once out of socket, the arm hangs limp. A shoulder separation is also called an AC separation. It is a separation of the acromioclavicular joint—the clavicle separates from the acromion process of the scapula. A subluxation is when the shoulder comes out and then goes back in on its own. It is typically bone rubbing on bone instead of gliding. Some of you may have a shoulder impingement. That is when the supraspinatus tendon is compressed between the humeral head and the acromion process, which causes pain and weakness in the shoulder.

7 The clavicle is susceptible to compressive forces and blows and will break if you fall on an outstretched arm. Often fractured because: of its shape, held in place by ligaments on each end, and there is little protection from outside forces.

It is the only bony attachment that the upper extremity has to the trunk. The clavicle has a sternal end (the end that articulates with the sternum) which is bigger and an acromial end (articulates with acromion process of the scapula) which is thinner.

8 Humerus = upper arm bone

9 The head fits in the glenoid cavity of the scapula. The anatomical neck is the natural curve around the head, above the tuberosities, and the surgical neck is below them. The greater tuberosity is the bigger bump located on the lateral side of the humerus and the lesser tuberosity is the smaller bump on the anterior side. The intertubercular groove is the natural line in between the greater and lesser tuberosities. The deltoid tuberosity is a bump about ½ way down the shaft. The capitulum is the specific name of the lateral rounded condyle and the trochlea is the specific name of the medial pointy condyle of the humerus. The medial and lateral epicondyles are the smaller bumps just above the condyles (capitulum and trochlea). On the anterior side, the divot between the condyles is called the coronoid fossa; on the posterior side there is a big divot called the olecranon fossa. The supracondylar ridges are the edges (ridges) just above the epicondyles.

10 Glenohumeral ligament—located beneath the anterior surface of the joint capsule and helps reinforce the joint cavity (superior, middle, & inferior). Coracohumeral ligament—goes between the anatomical neck of the humerus and the coracoid process of the scapula. Coracoacromial ligament—crosses between the coracoid process and the acromion process of the scapula. This helps limit the superior movement of the humeral head.

11 Ulna = “underneath” in anatomical position; the pinky finger side. The ulna is medial to the radius. The ulna has the prominent role of articulating with the humerus.

12 Olecranon process—top projection Coronoid process—lower projection Trochlear notch—notch in between the 2 processes Shaft Styloid process—point at the distal end Radial notch—groove on the lateral side of the coronoid process where the radius head will fit in **The top of the Ulna forms a “C.” The top part of the “C” is the olecranon process and the bottom part of the “C” is the coronoid process, with the trochlear notch in the middle.**

13 Radius is on the lateral side of the lower arm in anatomical position. It has the prominent role of articulating with the bones of the wrist. Head—proximal rounded head Radial tuberosity—bump below head Styloid process of the radius—distal point

14 15 The ulnohumeral joint is the true elbow joint—what type of joint is that?? The radiohumeral joint is where the capitulum from the humerus articulates with the head of the radius. Both the proximal and distal radioulnar joints (joints between the radius and ulna) are pivot joints.

Proximal Radioulnar—head of the radius articulates with the radial notch of the ulna. The annular ligament wraps around the radius and allows some rotation to occur.

Distal Radioulnar—distal ends of both the radius and ulna articulate

16 Ulna is medial so the medial collateral ligament goes along the ulna, whereas the lateral collateral ligament goes along the radius. Radioulnar Ligaments—Dorsal (back of the hand) and Palmar side both have radioulnar ligaments to connect the distal ends of the radius and ulna Annular Ligament—wraps around radius to allow for rotation

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