Pectorals

The pectoralis major muscle is a thick, fan shaped muscle situated on the front of the chest. It makes up the bulk of the chest muscle.

Deltoids

The deltoid muscle forms the rounded countour of the shoulder. It has lateral, posterior and anterior fibres that work together to produce movement of the arm

Latissimus dorsi

The latissimus dorsi is the larger, flat muscle on the trunk, posterior to the arm and partly covered by the trapezius at the top of the back.

Biceps/triceps

The biceps and triceps muscles form the muscle situated on the upper arm. The biceps is located on the inside of the upper arm. It has several functions, the most important being to rotate the forearm and flex the elbow.

The triceps muscle is the large muscle situated at the back of the upper arm. It is mainly responsibe for extension of the elbow joint.