The shoulder joint is a ball-and-socket joint that connects the humerus (the upper arm bone) to the scapula (shoulder blade). This joint allows for a wide range of motion, enabling movements such as lifting, rotating, and reaching. The shoulder joint is stabilized by a group of muscles and tendons known as the rotator cuff. The shoulder joint is surrounded by a capsule filled with synovial fluid, which helps reduce friction during movement. Ligaments provide additional support, connecting bones and maintaining stability. Common injuries to the shoulder joint include dislocations and rotator cuff tears, often resulting from overuse or trauma.