The fascial compartments of the limbs generally end at the joints; therefore, fluids and infections in compartments are usually contained and cannot readily spread to other compartments. 

The anterior compartment is exceptional in this regard because it communicates with the central compartment of the palm through the carpal tunnel 

The tendons of most flexor muscles are located on the anterior surface of the wrist and are held in place by the palmar carpal ligament and the flexor retinaculumtransverse carpal ligament), thickenings of the antebrachial fascia 

the five superficial and intermediate muscles cross the elbow joint, the three deep muscles do not.

All muscles in the anterior compartment of the forearm are supplied by the median and/or ulnar nerves (most by the median; only one and a half exceptions are supplied by the ulnar).

Functionally, the brachioradialis is a flexor of the forearm, but it is located in the posterior (posterolateral) or extensor compartment and is thus supplied by the radial nerve.

Therefore, the brachioradialis is a major exception to the rule that (1) the radial nerve supplies only extensor muscles and (2) that all flexors lie in the anterior (flexor) compartment.

 long flexors of the digits (flexor digitorum superficialis and flexor digitorum profundus) also flex the metacarpophalangeal and wrist joints.

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Is the most lateral of the superficial forearm flexors. Its lateral border forms the medial boundary of the cubital fossa.

 along with the Pronator Quadratus muscle, serves to pronate the forearm (turning it so that the palm faces posteriorly when the body is in the anatomical position).

The pronator teres has two heads—humeral and ulnar. Humeral connects to the medial epicondyle

Median Nerve innervation

Positive tinel sign on forearm, not the wrist

is a long fusiform muscle located medial to the pronator teres

The FCR produces flexion (when acting with the flexor carpi ulnaris) and abduction of the wrist (when acting with the extensors carpi radialis longus and brevis).

To test the flexor carpi radialis, the person is asked to flex the wrist against resistance. If acting normally, its tendon can be easily seen and palpated.

Good guide to radial nerve as it passes lateraly to it.It gets its blood from the Ulnar artery 

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passes superficial to the flexor retinaculum and attaches to it and the apex of the palmar aponeurosis

Dupuytrens Contracture produces the same position with the hand tightly contracted in a claw and flexed at the wrist.

When the muscle is tense, it’s tendon can put pressure on the ligament reproducing some of the symptoms of Carpal Tunnel Syndrome.

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is the most medial of the superficial flexor muscles. 

The FCU simultaneously flexes and adducts the hand at the wrist if acting alone. 

This muscle is exceptional among muscles of the anterior compartment, being fully innervated by the ulnar nerve.

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the FDS actually forms an intermediate layer between the superficial and the deep groups of forearm muscles

Near the wrist, the FDS gives rise to four tendons, which pass deep to the flexor retinaculum through the carpal tunnel to the fingers.

The four tendons are enclosed (along with the four tendons of the flexor digitorum profundus) in a synovial common flexor sheath

The FDS is capable of flexing each finger it serves independently.

flexor digitorum profundus (FDP) is the only muscle that can flex the distal interphalangeal joints of the fingers

(i.e., it curls the fingers and assists with flexion of the hand, making a fist).

. The part of the muscle going to the index finger usually separates from the rest of the muscle relatively early in the distal part of the forearm and is capable of independent contraction.

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the long flexor of the thumb

The FPL is the only muscle that flexes the interphalangeal joint of the thumb.

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The pronator quadratus is the prime mover for pronation. The muscle initiates pronation; it is assisted by the pronator teres when more speed and power are needed.

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