Deltoid

Definition

The deltoid is a thick, triangular muscle covering the shoulder joint, responsible for lifting the arm and giving the shoulder its range of motion. It plays a pivotal role in both the power and precision needed for arm movement.

Related terms

Rotator Cuff: A group of muscles and tendons that surround the shoulder joint, keeping the head of your upper arm bone firmly within the shallow socket of the shoulder.

Pectoralis Major:

A large muscle in the upper chest that assists in rotating and flexing the arm toward the body.

Trapezius:

A broad superficial muscle extending from your neck to your mid-back, involved in moving, rotating, and stabilizing the scapula (shoulder blade) and extending the neck