1. Biceps brachi
2. Brachialis
3. Brachioradialis
4. Triceps brachii
5. Anconeus
6. Pronator Teres
7. Pronator Quadratus
8. Supinator

Forearm Flexors

1. Biceps Brachii
2. Brachialis
3. Brachioradialis

Forearm Extensors

1. Triceps Brachii
2. Anconeus

Forearm Pronators

1. Pronator teres
2. Pronator quadratus

Supinator

Brachialis (Strongest Flexor)

Origin: Distal, anterior surface of Humerus

Insertion: Ulnar Tuberosity & Coronoid Process of Ulna

Action: Flexes Forearm @ elbow joint

Innervation: Musculocutaneous and Radial Nerves

Brachioradialis 

Origin: lateral border of distal end of humerus

Insertion: Superior to styloid process of radius

Action: Flexes forearm @ elbow joint; supinates and pronates forearm @ radioulnar joints to neutral position.

Innervation: Radial Nerve

Triceps Brachii (Antagonist) 

Origin: Long Head: Infraglenoid tubercle; Lateral Head: lateral and posterior surface of humerus superior to radial groove. Medial Head: entire posterior surface of humerus inferior to a groove for the radial nerve.

Insertion: Olecranon of Ulna

Action: EXTENDS forearm @ elbow joint and extends arm @ shoulder joint.

Innervation: Radial Nerve

Pronator Teres

Origin: Medial epicondyle of humerus and coronoid process of ulna

Insertion: Midlateral surface of radius

Action: Pronates forearm @ radioulnar joints and weakly flexes forearm @ elbow joint

Innervation: Median Nerve

Pronator Quadratus

Origin: Distal portion of shaft of ulna

Insertion: Distal portion of shaft of radius

Action: Pronates forearm @ radioulnar joints.

Innervation: Median Nerve

Supinator 

Origin: Lateral epicondyle of humerus and ridge near radial notch of ulna (supinator crest)

Insertion: Lateral surface of proximal 1/3rd of radius.

Action: Supinates forearm @ radioulnar joints.

Innervation: Deep Radial Nerve

Aconeus

Origin: Lateral epicondyle of humerus

Insertion: Olecranon and Superior Portion of shaft of Ulna

Action: Extends forearm @elbow joint

Innervation: Radial Nerve