Upper Body Muscles
Explore the major muscle groups of the chest, back, shoulders, and arms that drive upper-body movement and posture.
Chest and back
The chest is dominated by the pectoralis major, which pulls the arm across the body, while the back's superficial muscles, including the trapezius and latissimus dorsi, control shoulder blade movement and pull the arm downward and backward.
The muscles of the front of the body
This anterior view highlights the pectoral, abdominal, and anterior arm muscles that make up much of the upper body's visible musculature.
Pectoralis major
The main chest muscle flexes, adducts, and rotates the arm at the shoulder joint.
Trapezius
This broad back muscle stabilizes and moves the shoulder blade and supports head and neck movement.
Deltoid
The rounded shoulder muscle abducts the arm and assists with rotation at the shoulder joint.
Biceps & triceps brachii
These opposing arm muscles flex and extend the elbow joint during everyday movement.
Shoulders and arms
The deltoid caps the shoulder and works with the rotator cuff muscles to stabilize the joint through its wide range of motion, while the biceps brachii and triceps brachii work as an opposing pair to flex and extend the elbow.
Muscles work in opposing pairs
Most upper-body movement comes from pairs of muscles pulling in opposite directions, a relationship called an antagonistic pair.
Upper body muscles work in opposing pairs.
One muscle in the pair contracts to move a joint while its opposing partner relaxes and lengthens, as seen in the biceps and triceps working together to bend and straighten the elbow.