Ball and socket joints also allow flexion and extension. Flexion of the shoulder joint occurs when the humerus (upper arm) moves forwards from the rest of the body, which happens at the end of an ...

The deltoids are the muscles that cover the front, back and side of the shoulder joint — and they are essential for everyday movements like raising your arms, lifting a child or carrying groceries.

Extension – straightening a joint ... Circumduction – this is where the limb moves in a circle. This occurs at the shoulder joint during an overarm tennis serve. Rotation – this is where ...