The wrist and hand Flashcards
What are the bones in the wrist?
- distal radius
- distal ulna
- Carpals (lateral to medial)
- scaphoid, lunate, triquetrum, pisiform, trapzeoid, capitate, hamate
What are the 2 joints of the wrist?
Distal radioulnar joint: pivot joint, between distal radius and ulna
Radiocarpal: seperate capusle from the distal radioulnar, between radious and proximal row of carpals
What is the TFCC?
The triangular fibrocartilage complex
* between the ulna and proximal carpals
* Cartilaginous disc
* acts a a sort of meniscus
What are the movements of the wrist?
- flexion (palm to wrist)
- extension (wrist back)
- radial deviation (point hand to radius)
- ulnar deviation
- circumduction
What are the ligaments of the wrist?
- Radial collateral (lateral aspect)
- Ulnar collateral (medial aspect)
- Transverse carpal (palmar aspect): runs over the top of the wrist anteriorly and gives a roof over the carpal tunnel
[carpal tunnel syndrome: the median nerve gets compressed]
What are the anterior muscles in the wrist?
Flexor carpi radialis
* O: medial epicondyle, I: 2nd metacarpal, A: flex wrist and radial deviation
Flexor carpi ulnaris
* O: medial epicondyle, I: 5th metacarpal, A: flex wrist and ulnar deviation
Palmaris longus:
* O: medial epicondyle, I: palmar aponeurosis, A: tenses skin of wrist
What are the muscles of the wrist/hand posterior side?
Extensor carpi radialis longus:
* O: supracondylar area and lateral epicondyle
* I: 2nd mc
* A: extension and radial deviation
Extensor carpi radialis brevis
* O: lateral epicondyle
* I: 3rd mc
* A: extension and radial deviation
Extensor carpi ulnaris
* O: lateral epicondyle
* I: base fo 5th mc
* ulnar deviation and extension
What are the forearm muscles?
- Ext carpi radialis longus and brevis
- Extensor digitorum
- extensor carpi ulnaris
- pronator teres
- felxor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
What joints do wrist flexion and extension and what % each?
Occurs at both radiocarpal and midcarpal joints
* Flexion: RC 60%, MC 40%
* Extension: RC 80%, MC 20%
What does the radiocarpal do in flexion/extension?
- Extension and flexion occurs with convex lunate on concave radius, so they slide and roll in differnet directions
What does the radiocarpal joint do with ulnar/radial deviation?
There is a convex proximal row of carpals on a concave radius, which causes them roll and slide in opposite directions
What are the bones of the hand and how many in each category?
- 8 carpal
- 5 metacarpals
- 14 phalanges
Also metacarpal phalanage joints, PIP and DIP on digits 2-5 and IP on 1st digit
What are the movements of the hand?
- Flexion (make a fist)
- Extension (open fist)
- Abduction: splay fingers
- Adduction: bring fingers back together
What are the movements of the fingers?
- Abduction: “lego hand” like holding a coffee cup
- Adduction: bring thumb back to hand
- Flexion: from neutral bring thumb down to hand
- Extension: from neutral bring thumb up like a thumbs up
- Circumduction: circles
- Opposition: bring thumb to pinky
What are the extrinsic muscles of the hand/fingers
- Extensor digiti minimi: O: lateral epicondyle, I: 5th phalange
- Extensor digitorum: O: lateral epicondyle, I: 2, 3, 4
- Extensor indicis: O: distal ulna: 2nd phalange (index)
What do the flexor digitorum profundus and flexor digitorum superficialis do?
- FDP: O: proximal ulna, I: distal phalanges 2-5, A: phalangeal flexor
- FDS: O; medial epicondyle, I: middle phalange, A: phalnageal flexor
How do you isolate the flexor digitorum superficilais?
Stabilize all adjacent finger and try to flx teh 3rd phalange
What are the extrinisc muscles of thum (no OI)
- Abductor pollicis longus
- Extensor pollicis brevis
- extensor pollicus longus
- flexor pollicis longus
What are the intrinsic muscles of the thumb? no OI
- adductor pollciis
- Abductor pollicis brevis
- Flexor pollicis brevis
What is the anatomical snuffbox and what is inside it?
IT is created by the extrinisc (extensor tendons)
* portion of the scaphoid can be palpated
* the division of the radial nerve and radial artery can be found here (get a pulse)
What is the thenar eminence?
palm side near the thumb
3 intrinsic muscles involved but you can identofy them individually by palpatation
1. opponens pollicis
2. flexor pollicis brevis
3. abductor pollciis brevis
What is the hypothenar eminence? and what is the central compartment
on palm side, medial to body; also 3 intriniscs but cant identify by palpation
1. opponens digiti minimi
2. flexor digiti minimi
3. abductor digiti minimi
* the central compartment is the valley in the middle between the two emineces (the adductor pollicis is here)
What cmc joints are strong and which are mobile?
- 2nd and 3rd cmc joints are very strong
- 1, 4, 5th cmc joints are mobile
- mid carpal joint is not strong
What does the mobility of the CMC joints allow for (when gripping)?
- opposition and tight gripping
What are the functional grip movements of the hand?
Gripping
* power: add thumb to hook grip essentially
* cylinder (thumb goes into abduction (lego hand)
* sphericle (baseball)
* hook (thumb is not involved)
Prehension pinch
* tip to tip
* lateral (power pinch): strongest prehension grip (the thumb comes to the 2nd digit
* pulp to pulp (pads of fingers together)
Are the wirst flexor or extensors more dominant in the “opening” mechanism?
Wrist flexors are dominant
What is the role of wrist extensors in the opening/closing mechanism?
- extensors help leverage the flexors
- they neutralize the strong weifts felxor tendancy of the extrinsic finger flexors
- maintains optimum lenth for the extrinsic finger extensors while closing the hand
What is the dorsal hood?
Connector of fascial tissue sitting on dorsal aspect of hand
* bridge between intrinisc and extrinsic muscles of the hand
* maintain that relationship and gives us fine motor control
* boutinere deformity of fingers is caused from dorsal hood
Explain the opening and closing mechanism?
Opening:
* ?
Closing:
* wrist extensors are active
* extensor digitorum controls flexion at MCP
