Download - Muscles of the Forearm
Muscles of the Forearm
Dr.Nivin Sharaf MD
Objectives
• -Describe the function of the muscles in the anterior and posterior compartment of the forearm.
• -Name and identify the muscles in the anterior (flexor/pronator) and posterior (extensor/supinator) compartments of the forearm, noting their relations.
• -Name and identify the neurovascular structures in the anterior) and posterior compartments of the forearm, noting their relations.
Functional organization of Anterior and posterior forearm.
Names of the Muscles of forearm
• Many of them• Long names: good guide to location and function• Location: ie. superficial / deep
radial / ulnar(which side is the thumb on??)
• Function: ie. flexor / extensor adductor / abductor
• Does it act on the thumb (pollux) or the fingers (digits)?
Functional Organization
• Anterior compartment – flexor / pronator• Posterior Compartment – extensor /
supinator• Flex the wrist ………[flexor]• Extend the wrist ……..[extensor]• Pronate the forearm ……..[pronator]• Acting on wrist (carpus) only ……[carpi]• Acting on fingers ……..[digiti / digitorum]• Acting on thumb (pollux) ……[pollicus]
Flexion / Extension at the wrist joint.
Flexion
Extension
Adduction / abduction at the wrist joint.
Ad-duction Ab-duction
Movements of fingers.
MCP (condyloid jts):flexion / extensionabduction / adduction
IP (hinge jts): flexion / extension
XX
Movements of the thumb – a specialized digit, occur atright angles to the fingers. Mainly at the CMC (saddle) jt.
MCP – condyloid; IP – hinge (like fingers).
Muscles of
Forearm
Anterior forearm:Flexor / pronator Compartment.
Superficial:common flexor origin - pronator teres - flexor carpi radialis- palmaris longus - flexor digitorum superficialis, - flexor carpi ulnaris
Functional organization:
Only flex at the wrist.
- Flexor carpi radialis- Palmaris longus- Flexor carpi ulnaris
Muscles of the Forearm
Anterior Fore Arm
PassFailPassFail
Ant Fore armWrist FlexorsFCU+FCRFDSFDPPL
Wrist AddFCU
Wrist AbdFCR
Nerve Supply
Post. ForearmSuperficial disection
Nerve Supply
Radial Nerve
Anatomical snuff box
Post. Forearm
A:Extensor DigitorumB:Extensor Carpi UlnarisC:Brachio RadialisD:Biceps BrachiiE:TricepsF:Extensor Retinaculum
Anconeus
Muscles of the Forearm Post View
Origin :Lateral epicondyle of humerus Insertion Lateral surface of olecranon andsuperior part of posterior surface of ulna Action Assists triceps in extending forearm;stabilizes elbow joint; abducts ulna during pronation Innervation Radial nerve (C7, C8 and T1)
Radial nerve innervates the BEST. Brachioradialis Extensors Supinator Triceps
Deep posterior compartment.
- abductor pollicis longus - extensor pollicis brevis - extensor pollicis longus - extensor indicis- supinator
Functional organization:- extend hand at wrist - extend / abduct thumb - extend index finger- supinate
Deep Dissection Forearm
PostAnt
Quiz
12. Pronator Teres13. Flexor carpi radialis:14. Flexor Digitorum:15. Extensor carpi ulnaris:16. Extensor digitorum:17. Extensor carpi radialis:
Rotators of the Radius
Supinator
Pronators
Biceps Brachii
Pronation / Supination:
Occurs at radio-ulnar jts.Proximal:Head of radiusarticulates with radial notch of ulna (pivot jt). It is held in place by the annular ligament.
Distal – Radius pivots around the fixed distal end of ulna (pivot jt).
Radio-ulnar articulation is stabilized by interosseus membrane.
• Common Extensor Origin
• Common Extensor Origin
Course of radial and ulnar arteries in forearm
Axillary vein: continuation of basilic vein
Neurovasculature (deep).
Lateral: - radial artery - radial nerve
Midline: - median nerve- anterior interosseus a. - anterior interosseus n.(deep branch of median)
Medial: - ulnar artery(gives off common interosseus artery divides into anterior and posterior branches)
- ulner nerve
Neurovasculature.
Radial nerve and its branches supplyall muscles in posterior compartment, including brachioradialis (!).
- superficial radial nerve- deep radial nerve - posterior interosseus nerve.
Posterior interosseus artery runs between superficial and deep muscles
Neurovasculature.
Lateral: radial arteryradial nerve
Midline: median nerve[supplies all muscles except flexor carpi ulnaris and medial half of flexor digitorum profundous]
Medial: ulnar arteryulnar nerve
• Medial ½ of FDP• FCU• All hand muscles except
11/2 muscle groups(lateral 2 lumbricals and thenar muscles )
Ulnar Nerve
References
• Grey’s Anatomy• Netter• Keith Moore• www.maestro.uottawa.ca
• Recommended reading:• Clinically Oriented Anatomy,6th edition Keith
Moore• Pages:744-771
Thank you!