What are the three categories of muscle in the anterior compartment of the forearm?
Superficial, intermediate and deep
What is the general action of muscles in the anterior compartment of the forearm?
Flexion at the wrist and fingers and pronation
What are the superficial muscles in the anterior compartment of the forearm?
Flexor carpi ulnaris, palmaris longus, flexor carpi radialis and pronator teres.
Where does the common tendon of the superifical muscles of the anterior compartment of the arm origionate from?
Medial epicondyle of the humerus
Flexor carpi ulnaris attachments
Origionates from the medial epicondyle with the other superficial flexors. It also has a long origin from the ulna. It passes into the wrist, and attaches to the pisiform carpal bone.
Flexor carpi ulnaris actions
Flexion and adduction at the wrist
Flexor carpi ulnaris innervatioin
Palmaris longus attachments
Origionates from the medial epicondyle, attaches to the flexor retinaculum of the wrist.
Palmaris longus actions
Flexion at the wrist
Palmaris longus innervation
Flexor carpi radialis attachments
Origionate from the medial epicondyle, attaches to the base of metacarpals II and III.
Flexor carpi radialis actions
Flexion and abduction at the wrist
Flexor carpi radialis innervation
Pronator teres attachments
Two origins, one from the medial epicondyle, and the other from the coronoid process of the ulna. It attaches laterally to the midshaft of the radius.
Pronator teres actions
Pronation of the forearm
Pronator teres innervation
Which muscle lies in the intermediate compartment of the antierior forearm?
Flexor digitorum superficialis
Why is the flexor digitorum superficialis a good anatomical landmark in the forearm?
The median nerve and ulnar artery pass between its two heads, and then travel posteriorly.
Flexor digitorum superficialis attachments
It has two heads, one origionates from the medial epicondyle of the humerus, the other from the radius. The muscle splits into four tendons at the wrist, which travel through the carpel tunnel, and attaches to the middle phalanges of the four fingers.
Flexor digitorum superficialis actions
Flexes the metacarpal phalangeal joints and proximal interphalangeal joints at the four fingers.
Flexor digitorum superficialis innervation
What are the three muscles in the deep compartment of the anterior forearm?
Flexor digitorum profundus, flexor pollicus longus and pronator quadratus
Flexor digitorum profundus attachments
Origionates from the ulna and associated interosseous membrane. At the wrist, it splits into four tendons, that pass through the carpal tunnel and attach to the distal phalanges of the four fingers.
Flexor digitorum pofundus actions
It is the only muscle that can flex the distal interphalangeal joints of the fingers. It also flexes at metacarpophalangeal joints and at the wrist.
Flexor digitorum profundus innervation
The medial half (acts on the little and ring fingers) is innervated by the ulnar nerve. The lateral half (acts on the middle and index fingers) is innervated by the anterior interosseous branch of the median nerve.
Flexor pollicus longus attachments
Origionates from the anterior surface of the radius, and surrounding interosseus membrane. Attaches to the base of the distal phalanx of the thumb.
Flexor pollicus longus actions
Flexes the interphalangeal joint and metacarpophalangeal joint of the thumb.
Flexor pollicus longus innervation
Anterior interosseous branch of the median neve
Pronator quadratus attachments
Origionates from the anterior surface of the ulna, and attaches to the anterior surface of the radius.
Pronator quadratus actions
Pronates the forearm