Ulnar Nerve Flashcards
Root value of Ulnar Nerve;
C7, C8, T1
Root value of Ulnar Nerve supplying the Muscles of Palm;
C8, T1 {anterior division of lower trunk}
C7 fibres from Lateral Cord Supplies;
- Medial 1/2 of Flexor digitorum profundus
* Flexor carpi ulnaris
Course of Ulnar Nerve;
Passes behind the Medial Epicondyle of humerus →
Enters forearm →
Passes between FDP and FCU muscles →
Enters the Palm above Flexor Retinaculum →
Lies in the Guynon’s canal
What are the branches of Ulnar nerve in the Palm?
- Superficial Branch (Sensory)
* Deep Branch (Motor branch)
Deep branch of Ulnar nerve supplies;
All muscles of Palm Except LOAF muscles
L O A F muscle;
L - Lateral 2 Lumbricals
O - Opponens pollicis
A - Abductor pollicis brevis
F - Flexor pollicis brevis
Superficial branch of Ulnar Nerve supplies;
- Palmaris brevis
* Medial 1 and 1/2 digits
What is Pollock’s sign?
Loss of Flexion of Interphalangeal joints of medial two-fingers
Due to Ulnar nerve injury → FDP Tendon to medial half is paralysed
What is Wartenberg Sign?
Loss of addiction of Fifth digit (Palmar interossei adduction)
Due to Ulnar nerve injury
What is Wartenberg Syndrome?
Injury to Superficial Branch of Radial Nerve
What is Froment sign / Froment Test ?
To test adductor pollicis
Positive test shows → Compensatory flexion at their Phalangeal Joint of thumb
Due to Flexor pollicis longus, supplied by Anterior Interosseous nerve - branch of Median Nerve
Signs of Ulnar Injury;
Pollock’s sign
Wartenberg sign
Froment sign/Froment test
Lumbricals number
4 in Number;
From lateral to medial
1st and 2nd → Unipennate
3rd and 4th → Bipennate
Unipennate Lumbricals are supplied by;
1st and 2nd by Median Nerve
Bipennate Lumbricals are supplied by;
3rd and 4th → by Deep branch of Ulnar nerve
Lumbrical muscles;
Origin -
Insertion -
Origin - FDP tendon
Insertion - Dorsal digital expansion (extensor tendon)
Action of Lumbrical Muscles;
Had 2 Action;
- Flexion of Metacarpophalangeal Joint
- Extension of Interphalangeal Joint
Palmar Interossei Action
- Addiction of Fingers
- Flexion of MCP Joint
- Extension of IP Join
Finger without Palmar interossei attachment;
Middle finger
Because it is already in adducted position
Action of Dorsal Interossei
Abduction of Fingers
Flexion of MCP Joint
Extension of IP Joint
Metacarpal with no attachment of Dorsal Interossei
1st and 5th Metacarpals
Dorsal interossei is supplied by
Deep branch of Ulnar nerve
Anterior boundary of Midpalmar space;
- Palmar aponeurosis
- Superficial palmar arch
- FDS and FDP tendons to 3, 4, 5 fingers
- Ulnar bursa
- 2, 3, 4 - Lumbricals
Posterior boundary of Midpalmar space;
- 3rd, 4th, 5th Metacarpal bone
* Fascia over the Interosseous muscles
Medial and Lateral boundaries of Midpalmar space;
Medially - Medial palmar septum
Laterally- Intermediate palmar septum
Midpalmar space extends upto;
Proximally -
Distally -
Proximally - extend upto Space of Parona
Distally - extend up to 2nd, 3rd, 4th Web space through 2nd, 3rd, 4th Lumbrical canal
Thenar space extends upto;
Proximally -
Distally -
Proximally - extend upto Space of Parona
Distally - communicating with 1st Web space through 1st Lumbrical canal
Thenar space; Anterior Boundary
- Palmar aponeurosis
- Radial Bursa (around Flexor pollicis longus)
- FDP and FDS tendons to 2nd Metacarpal
- 1st Lumbrical (taking origin from FDP tendon to Index finger)
Thenar space; Posterior Boundary
Oblique head of Adductor pollicis (from 3rd Metacarpal)
Thenar space; Medial and Lateral Boundary
Medially - Intermediate Palmar Septum
Laterally- Lateral Palmar Septum
Infection from the Index finger spread to which space of palm?
Thenar space
