Adventitious bursitis overlying an osteochondroma of the humerus facing the thoracic wall

The upper limb consists of the arm, forearm, wrist, and hand bones. The humerus is the single bone of the upper arm region. Proximally, it has a large, spherical, smooth head that articulates with the glenoid cavity of the scapula to form the glenohumeral or shoulder joint. The margin of the head is the anatomical neck, a residual epiphyseal plate. Laterally it extends to form bony projections called the greater tubercle and the lesser tubercle. Next to the tubercles is the surgical neck, a...

Nine muscles are involved in arm movements. Two of these, the pectoralis major and latissimus dorsi, originate from the axial skeleton and are called axial muscles. The other seven originate from the scapula and are called the scapular muscles.
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...

The ulna and radius are parallel bones of the antebrachium or the forearm. The ulna lies medially and consists of a bony tip called the olecranon process at its proximal end. This hook-like projection articulates with the olecranon fossa of the humerus and forms the "hinged" ulnohumeral part of the elbow joint. This joint facilitates forearm extension and flexion while preventing its hyperextension. Similarly, the coronoid process, another bony projection on the proximal/anterior side...

The radius is longer of the two bones that make up the human antebrachium or forearm. At the proximal end, the radius articulates with the capitulum of the humerus and the radial notch of the ulna to form the elbow joint. At the distal end, the radius articulates with the ulna via the ulnar notch, forming the distal radioulnar joint. Distally, the radius also attaches to the carpal wrist bones (scaphoid and lunate) to form the radiocarpal joint.
The radius has a nail-shaped head, and a...

The thoracic or rib cage forms the body's thorax (chest) portion. Its primary function in the body is to protect vital organs in the thoracic cavity, such as the heart and the lungs. It consists of 12 pairs of ribs with their costal cartilages and the sternum. The ribs are anchored posteriorly to the 12 thoracic vertebrae (T1-T12).
The sternum is the elongated bony structure on the anterior side of the thoracic cage. It consists of three parts: the manubrium, the body, and the xiphoid...

The muscles surrounding the shoulder girdle, including the clavicle and scapula, primarily stabilize the scapula. This stable base allows other muscles to move the humerus effectively. Scapular movements often mirror those of the humerus and extend its range of motion. For instance, raising the arm above the head would not be feasible without simultaneous upward rotation of the scapula.
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...