Upper arm bone (humerus) Your deltoid muscles start near your clavicle and scapula. ... This is the main shoulder joint that has a “ball and socket” and assists with deltoid muscle function.

It’s attached to the humerus (the upper arm bone) via a ball-and-socket joint called the glenohumeral joint. ... Scapula function depends on these muscles, which include the: Levator scapulae.

From your shoulders to your fingers, your arms have many moving parts: joints, bones, muscles, nerves, tendons and ligaments. Mysterious arm pain that seemingly comes out of nowhere can arise if ...

These muscles work together to control arm movement and shoulder rotation. They also help keep the head of the upper arm bone, known as the humerus, in the socket of the shoulder blade, or scapula.

From your shoulders to your fingers, your arms have many moving parts: joints, bones, muscles, nerves, tendons and ligaments. Mysterious arm pain that seemingly comes out of nowhere can arise if ...

The shoulder is a mobile joint that connects the arm to the torso. It consists of a number of structures, including bones, that enable the arms to move and function.

Historically, bone’s functions in protecting vital organs and holding people up were well-known, and its relationships to things like the muscles—to which bone connects—were also recognized.

The bone itself was being broken down far more extensively than normal. Bones constantly remodel to stay healthy, but in this case, the bone was disappearing much quicker than it was being replaced.