Anatomy: Upper Fiber Muscles and their Functions

Arm Movement

• The teres minor muscle is involved in the lateral rotation of the arm.
• The deltoid muscle is responsible for the abduction of the arm.

Scapular Movement

• The levator scapulae muscle is responsible for the elevation of the scapula.
• The serratus anterior muscle assists in scapular protraction from a retracted position.

Neck Movement

• The scalene muscles are involved in the lateral flexion of the neck.

Finger Movement

• The extensor digitorum communis muscle is responsible for the extension of fingers #2-5 at the meta-carpo-phalangeal (MCP), proximal inter-phalangeal (PIP), and distal inter-phalangeal (DIP) joints.

Muscle Innervation

• The radial nerve innervates the Extensor Carpi radialis longus muscle.
• The ulnar nerve innervates the Flexor carpi ulnaris muscle, which is involved in the ulnar deviation of the hand at the wrist.
• The dorsal scapular nerve innervates the levator scapulae muscle.

Forearm Movement

• The pronator teres muscle assists in both pronation and supination of the forearm.