Muscles of the Forearm
Dr. Sama ul Haque
Objectives
• Identify the muscles in the anterior and posterior
compartments of the forearm in terms of their origin,
insertion, nerve supply and actions.
• Know the neurovascular structures in the anterior and
posterior compartments of the forearm.
• Discuss the functions of the muscles in the anterior
and posterior compartment of the forearm.
Functional
organization
of
Anterior and
posterior
Compartments of
forearm.
Names of the Muscles of forearm
• Long names: good guide to location and function
• Location: ie.
superficial / deep
radial / ulnar
• 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.
Extension
Flexion
Adduction / abduction at the wrist joint.
Adduction
Abduction
Movements of fingers.
Metacarpophalangeal (condyloid joints):
flexion / extension and abduction / adduction
Interphalangeal (hinge joints): flexion / extension
X
X
Movements of the thumb – a specialized digit, occur at
right angles to the fingers. Mainly at the Carpometacarpal
(saddle) joint. MCP – condyloid; IP – hinge (like fingers).
Radius
and
Ulna
Radius
and
Ulna
(Pronated)
Muscles of the anterior compartment of forearm
Muscles of the anterior compartment of forearm
Anterior Compartment of forearm
Superficial:
Common flexor origin
 Pronator Teres
 Flexor Carpi Radialis
 Palmaris Longus
 Flexor Digitorum
Superficialis,
 Flexor Carpi Ulnaris
Anterior Compartment of forearm
Functional organization:
Only flex at the wrist.
 Flexor carpi radialis
 Palmaris longus
 Flexor carpi ulnaris
Anterior Compartment of forearm
Deep Dissection Forearm (Anterior)
Neurovasculature of Anterior Compartment of forearm
Muscles of the posterior compartment of forearm
Muscles of the posterior compartment of forearm
Muscles of the posterior compartment of forearm
Muscles
of
Forearm
Muscles of the
Forearm (Post. View)
Anconeus
Posterior Forearm (Superficial dissection)
Nerve Supply
Radial Nerve
Anatomical snuff box
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 (Posterior)
Superior and Inferior radioulnar Joints
Superior radioulnar Joint:
 Head of radius articulates with radial notch of ulna
 Type: Pivot joint).
 It is held in place by the annular ligament.
 Radio-ulnar articulation is stabilized by interosseous
membrane.
Inferior radioulnar Joint:
Supination and Pronation
Course of radial and ulnar arteries in forearm
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 supply
all muscles in posterior compartment,
including Brachioradialis (!).
- superficial radial nerve
- deep radial nerve
- posterior interosseous nerve.
Posterior interosseous artery runs
between superficial and deep muscles
Radial & Ulnar Arteries
lateral
Radial artery
medial
Ulnar artery
Common interosseous
Dorsal and palmer
carpal branches
Deep (superficial)
palmar arches
Anterior
Posterior
Dorsal and palmer
carpal branches
superficial (deep)palmar arches
RELATION OF ARTERIES,
NERVES AND TENDONS
AT THE WRIST
NANAN
Superficial Radial Nerve
Radial Artery
Median Nerve
Ulnar Artery
Ulnar Nerve
MOVING LATERAL TO MEDIAL
1-9
1. Brachioradialis
6. Flexor Digitorum Superficialis
2. Superficial Radial n.
7. Ulnar Artery
3. Radial Artery
8. Ulnar Nerve
4. Flexor Carpi Radialis
9. Flexor Carpi Ulnaris
5. Median Nerve
Thumb