Each deltoid muscle is located where the ball-and-socket joint of your shoulder connects your humerus (upper arm bone) to your trunk. The primary function of the deltoid muscle is to move the ...

This is the main shoulder joint that has a “ball and socket” and assists with deltoid muscle function. It holds the “ball” of the humerus in the “socket” of the scapula ...

A problem with the deltoid muscle can affect the range of motion and function of the arm, making everyday activities like ...

and shoulder muscles. Scapula function depends on these muscles, which include the: Your scapula is key to proper movement of your arms and shoulders. When something goes wrong, it can cause ...

While other shoulder muscles function to elevate the arms or drive the shoulder forward, the rear delt muscles retract the shoulder to move the upper arms behind the torso, making this an equally ...

The primary function of the rear deltoids is shoulder extension, which work alongside your scapula, traps and muscles of the upper back to pull your shoulders back. They play a key part in all ...