Superficial Flexor Compartment of the Forearm.
The forearm is the region of the upper limb between the elbow joint proximally and the wrist joint distally.
There are two long bones in the forearm. The radius lies laterally under the thumb .
The ulna lies medially under the little finger.
This is a diagram of the cross-section through the upper third of the forearm.
At the top is the anterior or volar surface of the forearm.
At the bottom of the diagram is the posterior or dorsal surface of the forearm.
To the left is the lateral surface and to the right is the medial surface.
The next layer under the skin is the subcutaneous fat.
This is the Ulna, the interosseous membrane and the radius.
The extensor compartment is shown posteriorly.
The mobile wad of 3 laterally.
The deep flexor compartment is next to the ulna
and the superficial flexors towards the upper surface of the cross section.
There are 5 superficial forearm flexors.
An easy way to remember the muscles is to place your
opposite hand over the anterior aspect of the opposite
elbow joint also known as the cubital fossa.
This is a close up of the cubital fossa.
This shows the hand placed over the cubital fossa.
Each digit represents a different muscle.
The thumb is the pronator teres.
This pronates or internally rotates and flexes the forearm at the elbow joint.
The pronator teres can be seen closest to the radius.
The index finger represents flexor carpi radialis.
This muscle flexes and abducts the hand at the wrist joint.
The middle finger equates to the palmaris longus.
The palmaris longus flexes the hand at the wrist.
It tightens the palmar aponeurosis.
It is absent in 1 out of 15 people.
In cross-section the palmaris longus is a superficial structure.
The ring finger represents flexor digitorum superficialis.
This muscle flexes the fingers at the proximal interphalangeal joint
and the metacarpophalangeal joints.
It is deeper, seen here in cross-section
The little finger represents the flexor carpi ulnaris.
This muscle flexes and adducts the hand at the wrist joint.
It can be seen here in cross-section lying most medially.
So the superficial arm flexors include pronator teres, flexor carpi radialis, palmaris longus,
flexor digitorum superficialis and flexor carpi ulnaris.
Nerves.
The median nerve supplies all the superficial muscles of the forearm with one exception.
Flexor carpi ulnaris is supplied by the ulnar nerve.
In this diagram the median nerve may be seen next to the interosseous membrane.
The ulnar nerve is demonstrated between the deep flexor compartment and
flexor carpi ulnaris.