Question

While fireman Fred is fighting a fire in a building, part of the ceiling collapses, and a beam strikes him on his left shoulder. He is rescued, but has a great deal of pain in his shoulder. He cannot move his arm properly, especially in the anterior direction. His clavicle is not broken, and his humerus is intact. What is the probable nature of Fred’s injury?

Accepted Answer

Step 1: Identify the anatomical structures involved in shoulder movement, especially those responsible for moving the arm anteriorly. The main muscles that flex the arm at the shoulder (move it anteriorly) include the pectoralis major, anterior deltoid, and the coracobrachialis, all of which attach near the clavicle and humerus. Step 2: Since Fred's clavicle and humerus are intact, the injury likely involves soft tissues such as muscles, tendons, ligaments, or nerves around the shoulder joint rather than bone fractures. Step 3: Consider the mechanism of injury—a beam striking the left shoulder could cause damage to the shoulder joint capsule, rotator cuff muscles, or the brachial plexus nerves that innervate the muscles responsible for arm movement. Step 4: Given the inability to move the arm anteriorly and the absence of bone fractures, suspect a dislocation of the shoulder joint (glenohumeral joint), particularly an anterior dislocation, which is the most common type and can impair anterior arm movement. Step 5: Alternatively, consider injury to the muscles or tendons that flex the shoulder, such as a tear in the pectoralis major or damage to the anterior deltoid, or nerve injury affecting motor control; clinical examination and imaging would help confirm the diagnosis.

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Shoulder Anatomy and Joint Structure

Types of Shoulder Injuries

Clinical Signs and Symptoms of Shoulder Trauma