Front of Forearm Lectures

The forearmFront of forearm

Antebrachial fascia:The deep fascia of forearm• Thicker posterior than

anterior surface• strengthened above by

bicipital aponeurosis• thickened along post.

Border of ulna----unlar aponeurosis

• in the lower par of forearm----flexor and extensor retinaculae

Muscles of the front of forearmThey are arranged in 2 groups:1- superficial group: 5 muscles 2- deep group: 3 muscles

1-Pronator teres I- Origin: A-humeral head: from common flexor origin+ lower part of med. Supracondylar ridge. B- ulnar head (deep head): medial border of coronoid processII- Insertion: rough area at the middle of lateral surface of radius at max. convexityIII- nerve supply:Median N.IV- Action:1-Pronation2- week flexion of elbow

Pronator quadrarus

2-Flexor carpi radialis

Origin: C.F.O.Course: Its tendon passes in special compartment of flexor retinaculumInsertion: front of bases of 2nd and 3rd metacarpal bonesNerve supply: Median NerveAction: 1- Flexion and Abduction of Wrist2- Week flexion of elbow

Palmaris longusThe muscle may be absentOrigin: CFOInsertion: the tendon passes in front of the flexor retinaculum to be inserted in the apex of the palmer aponeurosis.Nerve supply: Median nerveActions: 1- tense the palmer aponeurosis2- flexion of the wrist

Ant. view

Post.view

Origin: a) Humeral head: CFOb) Ulnar head: from ulnar aponeurosis from upper 2/3 of posterior border of ulna+ from medial side of olecranon process of ulna

Flexor carpi ulnaris

Insertion: 1-Pisiform bone 2-Hook of hamate+5th metacarpal bone via pisihamate pisimetacarpal ligamentsNerve supply: Ulnar N.Actions: 1- flexion and adduction of wrist.2- Weak flexion of elbow

Flexor digitorum superficialisOrigin:Humero-ulnar head: CFO + ulnar collateral lig.+ medial border of coronoid processRadial head: Anterior oblique line of radius.Insertion: the 2 slips of each of the 4 tendons form a tunnel though which passes the corresponding tendon of FDP. The 2 slips inserted into the sides of middle phalanges of med. 4 fingers.Nerve supply: Median nerveAction: flexion of middle and proximal phalanges. 2-Flexion of the wrist. 3- flexion of elbow

Deep group:1-Flexor pollicis longusOrigin:Upper 2/3 of anterior surface of shaft of radiusAnterior surface of interosseous membrane.Occasional head from medial border of coronoid process of ulna below the pronator teres.Insertion: palmar surface of the base of terminal phalanx of the thumb.Nerve supply: anterior interoseous N.

Action: flexion of all joints of thumb and of wrist

2-Flexor digitorum profundusOrigin: Upper ¾ of ant. And med. Surfaces of the ulnaUpper 2/3 of post. Border of ulna by aponeurosisAnterior surface of interosseous membraneInsertion: 4 tendon each passes into a gutter formed by slips of tendon of FDS to be inserted into bases of terminal phalanges of med. 4 fingers.Nerve supply: lat. ½ by anterior interosseous N.+ med. ½ by ulnar nerveAction: flexion of all joints of med 4 finger+ flexion of wrist.

3- Pronator quadratus:Origin: from oblique ridge on the ant.surface of lower ¼ of shaft of ulna.Insertion: front and med. Surface of lower ¼ of radiusNerve supply ant. Interosseous N.Actions: pronation of forearmFixed radius to ulna

Pronator quadrarus

Cubital fossaTriangular space in front of elbowBoundaries: Base above: imaginary line between two epicondyles. Laterally: brachioradialis Medially: pronator teres Apex below: brachioradialis overlaps pronator.Floor: Brachialis and supinator

Brachialis

supinator

Roof:• skin, • fascia, • bicipital aponeurosis • Parts of cephalic and basilic

veins and median cubital vein.• Anterior branches of both

lateral and medial cutaneous nerves of forearm

Median cubital vein

Contents: from med.to lat.:1-Median nerve.2- End of brachial artery and its 2 terminal branches, radial leaves fossa at apex while ulnar passes deep to ulnar head of pronator teres3- Biceps tendon 4- Radial N. dividing into…

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