Functional anatomy of upper limb 3

Question 1

Learning outcomes

Answer 1

• Describe the following types of grip: power grip, hook grip and precision grip
• Demonstrate the power grip, hook grip and precision grip and identify the muscles responsible for producing these specific grips

Question 2

Movements of hand recap

Answer 2

Flexion -anterior compartment of forearm
Extension -posterior compartment of forearm
Ulnar/medial deviation/Adduction
Radial/lateral deviation/Abduction
Movements of the wrist are caused by muscles in the forearm

Question 3

Movements of hand recap 2

Answer 3

Flexion – FCU, FCR, FDS, (FDP, PL, FPL)
Extension – ECRL, ECRB, ECU, ED
Adduction – ECU and FCU
Abduction – FCR, ECRL, ECRB and APL

Question 4

Muscles in anterior compartment recap

Answer 4

Pronator teres
FCR
PL
FCU
FDS
FDP
FPL
Pronator quadratus
All innervated by median nerve bar FCU and median half of FDP (ulnar)

Question 5

Small muscles of hand

Answer 5

Located within the hand itself
‘Intrinsic’
‘Extrinsic’ – muscles of the forearm

Responsible for the fine motor function
They include: 
-Muscles of the thenar eminence
-Muscles of the hypothenar eminence
-Interossei
-Adductor pollicis - Large triangular muscle, originates from metacarpals/carpals, attaches into base of proximal phalanx of thumb, causes adduction
-Lumbricals

Question 6

Thenar/ hypothenar eminences

Answer 6

Thenar muscles
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis

Hypothenar muscles
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi

All originate from the flexor retinaculum and from carpal bones
Abductors and flexors insert into proximal phalanx
Opponensinsert to metacarpals

Question 7

Interossei

Answer 7

Palmar interossei
Cause adductionof the digits
Originate from the metacarpals
Attach to proximal phalanx and extensor expansion hood

Dorsal interossei
Cause abduction of the digits
Originate from the metacarpals
Attach to proximal phalanx and extensor expansion hood

Pad Dab ( 3 for P, 4 for Dor)

Question 8

Lumbricals

Answer 8

Originates from the tendons of FDP
Attaches into the extensor expansion hood
Causes flexion at the MCP joint and extension at the IP joints
The lateral two lumbricals are innervated by the median nerve
The medial two lumbricals are innervated by the ulnar nerve

Question 9

Innervation of hand and forearm

Answer 9

All muscles in the anterior forearm are innervated by the median nerve
EXCEPT: flexor carpi ulnarisand the medial half of flexor digitorum profundus

All muscles in the hand are innervated by the ulnar nerve
EXCEPT: lateral two lumbricals, opponenspollicis, abductor pollicis brevis, flexor pollicis brevis

All muscles in the posterior forearm and innervated by the radial nerve

Half LOAF - HALF Lumbricals (lat 2), Opponens pollicis, Adductor pollicis, Flexor pollicis brevis

Question 10

Grip types

Answer 10

Power types
Cylindrical
Spherical
Hook- Long flexor muscles of the hand + short (intrinsic) muscles of the hand

Precision Grips
Pinch
Pincer
Prehension
Lumbrical
Less reliant on force
More focused on delicate, fine movements
Involvement of small muscles of the hand
Some long flexors may be involved for stabilising
Combinations/modifications are possible