The latissimus dorsi muscle is one of the strongest and largest muscles in the back. This muscle is used when lifting the arms up to the side and the extension of the shoulder.
The pectoralis major muscle is the large muscle that makes up the muscular portion of the chest. When the tendon ruptures, it most likely tears off the arm bone at its insertion. Injury typically occurs when an eccentric load is applied to the muscle, such as with bench pressing, and failure usually occurs through the tendon.
Ehlers-Danlos syndrome is a disorder that affects your connective tissues - primarily your skin, joints, and blood vessel walls. These connective tissues provide strength and elasticity to the structures of the body.
The sternoclavicular joint, also known as the SC joint, is a small joint that connects your collarbone (clavicle) to the chest bone (sternum). Sternoclavicular joint instability (dislocation) is a relatively rare problem, and is usually the result of direct trauma to this area.