Shoulder Complex Anatomy Quiz

A fracture of the clavicle, typically caused by a direct blow to the shoulder. The fracture can be either complete or incomplete.

The sternocleidomastoid muscle pulls the medial fragment of a clavicle fracture superiorly.

The pectoralis major muscle pulls the lateral fragment of a clavicle fracture medially, while gravity pulls it downwards.

The space between the clavicle and the first rib, housing the subclavian artery and brachial plexus.

A flat, triangular bone situated on the posterior thoracic wall (T2 to T7 ribs).

The summit of the shoulder, which is the lateral extension of the scapula.

Located anterior and superior to the scapula, it helps prevent superior translation of the humerus.

An extension of the acromion process medially. It helps locate structures above and below it.

The shoulder complex is a highly mobile joint system, with a combined range of motion of 0-180 degrees in flexion and abduction, 0-90 degrees in external rotation, and 0-70 degrees in internal rotation. This exceptional mobility is achieved through the interaction of six moving areas, including both true and false joints.

Scapulohumeral rhythm is the coordinated movement of the scapula and humerus during shoulder motion. It typically involves a 2:1 ratio, meaning the humerus moves twice as much as the scapula. This synchronized movement helps to maintain stability and optimize range of motion.

The SC (Sternoclavicular) joint is the only direct connection between the shoulder complex and the axial skeleton. It is responsible for providing stability and transmitting forces from the upper limb to the trunk.

The GH (Glenohumeral) joint is the most important true joint in the shoulder complex, providing the greatest mobility. It's a synovial ball and socket joint, allowing for a wide range of movements.

The rotator cuff muscles, including supraspinatus, infraspinatus, teres minor, and subscapularis, play a crucial role in stabilizing the humeral head within the glenoid fossa. They contract during movement to maintain stability.

The clavicle is a long, slender bone located at the root of the neck, and is S-shaped. It plays an important role in supporting the shoulder and transmitting forces from the upper limb to the trunk.

The clavicle is frequently fractured due to falls on an outstretched hand (FOOSH) or falls on the shoulder (FOS). These injuries are common in the elderly population due to their slower reaction times.

The acromioclavicular (AC) joint is a joint that allows the clavicle to move slightly against the scapula. It is located at the top of the shoulder. This joint is often injured in athletes or people who fall on their shoulder.

A fracture of the humerus in the posterior shaft region that can damage the radial nerve. This injury affects the muscles responsible for finger and wrist extension, but elbow extension remains intact due to the triceps being innervated higher on the radial nerve.

The only joint that connects the upper limb to the axial skeleton, allowing for movement and stability of the shoulder.

A saddle-shaped joint allowing for a variety of movements and acting as the central connection between the clavicle and the axial skeleton.

The sternoclavicular joint involves the articulation of two bones: the medial end of the clavicle and the manubrium of the sternum.

A strong ligament that stabilizes the sternoclavicular joint, limiting excessive depression of the clavicle (downward movement).

A ligament that connects the first rib to the clavicle, preventing excessive elevation of the clavicle.

A strong ligament connecting the sternum and the clavicle that plays a vital role in stabilizing the joint and preventing various excessive movements.

A disc-shaped structure found within the sternoclavicular joint. It functions as a shock absorber and acts as a pivot point for various movements of the upper limb.

A force that causes movement in a straight line.

A combination of two forces that act in opposite directions to create a rotational movement. For example, upward and downward forces can cause rotation.

The muscles surrounding the shoulder joint, mainly the supraspinatus, infraspinatus, teres minor, and subscapularis, which help stabilize the humeral head within the glenoid fossa.

The upward force of the deltoid muscle is balanced by the downward force of gravity, allowing the shoulder to abduct smoothly.

A type of synovial joint that allows for slight gliding movements. It is found where the acromion (part of the scapula) meets the lateral end of the clavicle (collarbone).

The ligaments that support the acromioclavicular joint and help to prevent excessive movement. They include the acromioclavicular ligament (AC), coracoclavicular ligament (CC), and the acromioclavicular disc.

A strong ligament that attaches the acromion process to the clavicle bone. It plays a crucial role in stabilizing and supporting the joint.

This ligament has two parts: the conoid and trapezoid ligaments. It connects the coracoid process of the scapula to the clavicle.

A fibrocartilaginous structure found within the acromioclavicular joint. It acts as a shock absorber and helps to improve joint stability.

A type of synovial joint that allows for a wide range of motion, including flexion, extension, abduction, adduction, internal and external rotation, and circumduction. It is found where the humerus (upper arm bone) articulates with the scapula (shoulder blade).

The head of the humerus bone has specific orientations, which contribute to the overall shape and stability of the joint. The angle of inclination is a key factor in determining this.

A measurement of the angle between the axis of the humeral head and neck and the axis of the humeral shaft. This angle plays a role in the overall stability and mobility of the shoulder joint.

The space in the shoulder that is formed between the teres minor, teres major, long head of the triceps, and humerus. It contains the axillary nerve and posterior circumflex humeral artery.

The space in the shoulder that is formed between the teres minor, teres major, and the long head of the triceps. It contains the circumflex scapular artery.

The anterior (front) wall of the axilla is made up of the pectoralis minor, pectoralis major, and subclavius muscles.

The posterior (back) wall of the axilla is made up of the subscapularis, latissimus dorsi, and teres major muscles.

The lateral (side) wall of the axilla is made up of the biceps brachii in the bicipital groove and the coracobrachialis muscle.

The medial (inner) wall of the axilla is formed by ribs 2-6 and the serratus anterior muscle.

The brachial plexus is a network of nerves that provides innervation to the upper limb. It is formed by the anterior rami of spinal nerves C5-T1. This means that the brachial plexus includes the roots, trunks, divisions, cords and branches.

The musculocutaneous nerve is a branch of the lateral cord of the brachial plexus. It travels through the coracobrachialis muscle and ultimately supplies the biceps brachii and brachialis.