Glosaurus
Human Anatomy

Shoulder joint

A highly mobile joint that connects the upper limb to the torso and allows for a wide range of motion.
The shoulder joint, also known as the glenohumeral joint, is a ball-and-socket joint comprising the humeral head of the upper arm bone and the glenoid cavity of the scapula. This structure is surrounded by a complex arrangement of muscles, tendons, and ligaments that not only provide stability but also facilitate the extensive motion of the arm and shoulder. The shoulder joint is unique in its design, allowing for an exceptional range of motion, crucial for various daily activities.
Terminologia Anatomica
articulatio humeri
System
Musculoskeletal system
Function
The shoulder joint plays a vital role in the overall movement and function of the upper limb. It allows for movements such as flexion, extension, abduction, adduction, internal rotation, and external rotation, enabling activities like lifting, reaching, throwing, and pushing. Furthermore, the intricate network of muscles that reinforce the shoulder, notably the rotator cuff group, contributes to both stability and mobility. This combination allows the arm to perform complex, coordinated actions, facilitating intricate tasks that require fine motor skills. The flexibility of the shoulder joint is essential for athletes and individuals engaged in labor-intensive activities, providing the ability to execute movements that require speed and precision, which are critical for optimal performance.
Location
Situated at the proximal end of the humerus, the shoulder joint is located laterally at the upper portion of the arm, floating at the junction where the arm meets the torso. More specifically, the glenohumeral joint is formed by the articulation of the rounded head of the humerus with the shallow glenoid cavity of the scapula, which is oriented laterally and slightly angled upwards. This location allows for its substantial range of movement and is surrounded by a joint capsule that contains synovial fluid, lubricating the joint and enhancing its functionality. The shoulder joint is easily palpated and can be found by locating the acromion process of the scapula, which serves as a prominent bony landmark.
Did You Know?
  • The shoulder joint is one of the most mobile joints in the human body, allowing for movements in almost every direction.
  • Injuries to the shoulder joint, such as rotator cuff tears, are common among athletes, especially in sports that require overhead movements.
  • Unlike many other joints, the shoulder joint relies heavily on muscular support for stability rather than bony anatomy.
  • The range of motion at the shoulder joint is so extensive that humans can reach their back, touch their toes, and even throw objects in different directions.