Unit 11: Distal upper limb Flashcards
What is the function od the radio-ulnar joint?
Pronation and supination
What is the function of the wrist or carpus joint?
Flexion
Extension
Abduction and adduction
What is the function of the digitorum joint (extrinsic and intrinsic)?
Flexion Extension
Abduction Adduction
What is the function of the pollicis joint?
Flexion /extension
Abduction /Adduction
Oppose
What is the anterior compartment of the forearm associated with?
Pronation
What are the three layers of muscles in the forearm?
Superficial
Intermediate
Deep
What is the common origin of the muscles in the superficial compartment of the anterior forearm?
The medial epicondyle of the humerus
What are the four muscles in the superficial compartment of the anterior forearm
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
What is the function of flexor carpi radialis?
Flexes and abducts the wrist joint
What is the function of flexor carpi ulnaris?
Flexion and adducts the wrist joint
What is the function of pronator teres?
Pronation of the forearm
What is the function of palmaris longus?
No specific function
Evolutionary importance in resisting shearing forces with gripping gripping
Is residual
If present contributes to palmar aponeurosis.
What muscle is in the intermediate compartment of the anterior forearm?
Flexor digitorum superficials
What is the origin and insertion of the flexor digitorum superficialis?
Origin: Medical epidcondyle of humerus and well as ulnar and radius
Insertion: middle phalanx of each digit (not thumb)
What are the muscles found in the deep compartment of the anterior forearm?
Flexor digitorum profundus
Flexor pollicis longus
Pronator Quadratus
What is the relationship between the insertion of the flexor digitorum superficialis and flexor digitorum profundus?
Superficialis - inserts onto middle phalanx
Profundus - inserts onto distal phalanx
Hence the superficialis tendon splits into two (on the the medial and lateral side of each phalanx) to allow the profundis to pass through
What innervates the posterior forearm?
The radial nerve
What innervates the anterior forearm?
Mainly the median nerve
Some contribution from the ulnar (the flexor carpi ulnaris and 1/2 the flexor digitorum profundis)
What is the relevant anatomy of carpal tunnel syndrome?
Cut in transverse section the carpal bones make a U boat like shape
The flexor retinaculum forms a roof over this boat shape
The space contains the tendons from all the flexor muscles of the anterior forearm
And the median nerve
What is the clinical importance of carpal tunnel syndrome?
Inflammation from repetitive strain injury in the wrist
Narrows the space deep to the flexor retinaculum - puts pressure on the medial nerve within the space
Loss of median nerve function to the hand
What is the presentation of carpal tunnel syndrome?
Pain or parasthesia (numbness and tingling) , or weakness in the median nerve territory.
Involves the first 3.5 digits.
Is progressive
What is the common origin of the superficial muscles in the extensor/posterior compartment of the forearm?
The lateral epicondyle and the supraepicondylar ridge.
What is the main function of the posterior forearm muscles?
Extensors of the fingers and thumb
Movement of the wrist joint
Supination
What muscle is the anomally of the posterior compartment of the forearm?
The brachioradialis muscle
Is a flexor not an extensor
Is located at the junction between the anterior and posterior compartment
But is innervates by the radial nerve.
What are the two different layers of the muscles in the posterior compartment of the forearm?
The superficial
The deep
Some people may consider the outcropping muscles a third category (from the deep muscles)
What are the seven muscles in the superificial layer of the posterior compartment of the forearm?
The brachioradialis
The extensor carpi radialis longus
The extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi.
Extensor carpi ulnaris
Anoconeus
What is the anatomy relating to the tendons from the posterior compartment of the forearm?
Pass under the extensor retinaculum
Also insert into the extensor hood**
What is the common insertion of the deep layer of muscles in the posterior forarm?
Posterior radius / ulnar and the
Interosseous membrane.
What are the muscles in the deep compartment of the posterior forearm?
Supinator
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indices
What is the innervation to the extensor compartment of the forearm?**
The radial nerve
Branches into the muscular branch (for extensors of the arm and forearm)
Branches into the cutaneous branch for portion of the arm, forearm and
dorsum hand.
What are the alternative names for radial nerve palsy?
Crutch palsy
Saturday Night Syndrome
Due to causes: pressure in axilla from crutch or drunk sleep position with arm over chair
What are the potential causes of radial nerve palsy?
Impinge within axilla e.g poorly fitted crutches
Broken humerus
How does radial nerve palsy present?
Motor loss: unable to extend the wrist so presents with wrist drop
Sensory loss: most noticeable on the dorsum of the hand.
Describe the innervation of the superficial anterior compartment of the forearm.
All muscles are innervated by the median nerve
Except the flexor carpi ulnaris which is innervated by the ulnar nerve.