Posterior or rear deltoid — responsible for shoulder extension. Your deltoids work alongside your other shoulder muscles ...

Your upper arm extends from your shoulder to your ... about the different muscles, it’s important to understand the four major types of movement they’re involved in: Your forearm contains ...

Deltoid Abduction of the shoulder (moving the arm outwards and away from the body) Outward arm action in a jumping jack Rotator cuffs A group of stabilising muscles of the shoulder which helps to ...