Question

actions of these muscles

Muscle                                    origin                            insertion                        action

Brachialis	Distal portion of anterior humerus	Coronoid process of ulna
Pronator teres	Medial epicondyle of humerus and coronoid of ulna	Midshaft of radius
Flexor carpi radialis	Medial epicondyle of humerus	Base of 2nd and 3rd metacarpals
Extensor digitorum	Lateral epicondyle of humerus	By tendon into distal phalanges
Supinator	Lateral epicondyle of humerus; proximal ulna	Proximal shaft of radius

Answer 1

Actions of muscles

1. Brachialis - this muscle helps in flexion of forearm at the level of elbow joint. It brings forearm up and closer to the arm.

2. Pronator teres- as the name suggests, pronator teres helps in pronation of forearm. It means when forearm is pronated, then the palm faces inferiorly. It also help in flexion of forearm.

3. Flexor carpi radialis-  its major function is to flex the wrist. It also flexes the elbow. Also at the wrist joint, this muscle helps in abduction of wrist.

4. Extensor digitorum- it helps in extension of metacarpophalangeal and interphalangeal joints of the four phalanges (excluding thumb).

5. Supinator- helps in supination of forearm. It means that the palm will face upwards. This occur at the proximal radioulnar joint when the radius is rotated laterally by supinator muscle.