Wrist Flashcards
Why does the position of the wrist significantly affect the function of the hand
Because many of the muscles and tendons which control the digits originate extrinsic to the hand in the forearm
What is the most impotent function of the wrist
Provide adequate function of the hand as well as stability
A weak or painful wrist often assumes a position which will interre with the optimal _____
Length tension relationship
What are the two primary articulations in the wrist
Mid carpal and radiocarpal joints and there are numerous Intercarpal articulations
_____ serves as a spacer between the distal radioulnar joint and the hand
The wrist
_____ separates the extensor Carpi radialis brevis tendon from the extensor pollicis longus
Lister’s tubercle or dorsal tubercle
Where does the radial collateral ligament attach
Radial styloid process that projects from the lateral side of the distal radius
The surface of the radius is ______ with an ulnar angulation of _____ and a palmar angulation of ______
Concave
25 degrees
10 degrees
What is the functional significance of the distal osteology of the radius
You has more ulnar deviation and it creates stability because of the way we function
_____ styloid is sharper and smaller
Ulnar
What muscle goes around the styloid process of the ulna
Extensor Carpi ulnaris
What are the proximal and distal rows of the carpal bones
Proximal–scaphoid lunate triquetrum pisiform
Distal– trapezium trapezoid capitate hamate
____ has a proximal and distal pole separated by a waist
Scaphoid
How does the scaphoid articulate with the radius
Convex proximal surface
Most blood vessels enter the scaphoid through the___
Distal pole
_____ is vulnerable to fractures
Scaphoid
_____ fractures to the proximal part of this bone often have long healing times and frequently require surgery
Scaphoid
How does the lunate articulate with the radius
Convex proximally to articulate with the radius
What is the most unstable carpal
Lunate
_____ is the most medial in the proximal row of carpal bones
Triquetrum
__ is the sesamoid bone
Pisiform
_____ is embedded in the flexor Carpi ulnaris tendon
Pisiform
_____ serves as an attachment for the abductor digiti minimi and transverse carpal ligament.
Pisiform
_____ is concave proximally to articulate with the distal scaphoid
Trapezium
How does the trapezium articulate with the thumb
The distal end articulates with the base of the first metacarpal and is saddle shaped.
_____ articulates with the scaphoid proximally and second metacarpal distally
Trapezoid
____ is the largest bone and is located in the center of the wrist
Capitate
What does the capitate articulate with
Articulates proximally with the scaphoid and lunate and distally with the third metacarpal
What is the attachment for the transverse carpal ligament
Hook of the hamate
____ articulates with the 4th and 5th metacarpals distally
Hamate
____ proximally projects towards the lunate
Hamate
_____ provides the functional mobility of the ulnar side of the hand
Hamate
______ is the space on the palmar side of the wrist between the transverse carpal ligament which arches over the concavity formed by the carpal bones
Carpal tunnel
_____ serves as an attaché nt for a number of muscles inside the hand
Transverse carpal ligament
What does the carpal tunnel contain
The median nerve and extrinsic finger flexor tendons
What is carpal tunnel syndrome
Compression of the median nerve within the carpal tunnel
Causes of carpal tunnel are
Trauma
Repetitive activity
Systemic illness
Carpal tunnel syndrome leads to
Pain
Paresthesias
Numbness
Atrophy of thenar eminance and weakness of median nerve Innervated muscles
What are the two primary articulations of the wrist
Radiocarpal joint
Mid carpal joint
_____ row movement depends on ____ row movement for movements of the wrist
Proximal
Distal
Proximal row stability and range depend greatly on ____
Ligament integrity and articular surface anatomy
The ____ is the linkage between the distal and proximal rows
Scaphoid
How does the radiocarpal joint articulate
The concave surface of the radius articulates with the convex surface of the scaphoid and lunate. There is also an adjacent articular disc known as the triangular Fibrocartilage.
Stability of the radiocarpal joint is provided by _____
Radiocarpal ligaments
_____ resist palmar and ulnar displacement of the scaphoid and lunate
Radiocarpal ligaments
How is force transferred during weight bearing on the radiocarpal joint
80% through the scaphoid and lunate to the radius
20% transferred to the ulna through the articular disc
_____ articulation between the proximal and distal rows of carpals
Mid carpal joint
What is the medial compartment
Convex head of the capitate articulates with concave surface of the scaphoid, lunate and triquetrum
What is the lateral compartment
Concave surface of the trapezium and trapezoid articulates with the convex distal pole of the scaphoid.
Which compartment has less movement
Lateral
Ligaments are classified into which two types
Intrinsic and extrinsic
What are the functions of the ligaments
Maintain alignment of the carpal bones
Transfers forces between carpal bones
Transfers forces across the proximal and distal rows
Provide sensory feedback
What are the extrinsic ligaments
Dorsal radiocarpal
Radial collateral
Palmar radiocarpal
_____ reinforces the posterior radiocarpal joint, guides motion in the proximal row
Dorsal radiocarpal ligament
The dorsal radiocarpal ligament restrains____
Anterior dislocation of the lunate
_____ restrains ulnar deviation
Radial collateral ligament
_____ made up of three ligaments that are stronger and thicker than the dorsal ligaments
Palmar radiocarpal ligaments
______ restrain wrist extension
Palmar radiocarpal ligament
_____ bindw the radius and the ulna together while allowing the radius to rotate around the fixed ulna.
Triangular Fibrocartilage complex
What does the TFCC stabilize
The distal radioulnar joint
What does the TFCC reinforce
The ulnar side of the wrist
TFCC is a _____ disc that is in a triangular shape
Biconcave
What does the TFCC articulate with
Proximally with the ulna
Distally with the lunate and triquetrum
The central portion of the TFCC disc is _____ a vascular
80 percent
What are the ligaments in the ulnocarpal space
Palmar ulnocarpal ligament
Ulnar collateral ligament
_____ reinforce the ulnar side of the wrist while allowing pronation and supination
Palmar ulnocarpal ligament
Ulnar collateral ligament
____ fills the gaps in the ulnocarpal space
Meniscus “homologue”
_____ link the bones in the sme row
Intrinsic wrist ligaments
The intrinsic wrist ligaments are stronger ____ than ____
Volarly
Dorsally
What are the ligaments of the intrinsic wrist
Short ligaments
Long ligaments
Intermediate ligaments
_____ connects the bones of the distal row and provides stability and allows them to function as a single mechanical row.
Short ligaments
What are the intermediate ligaments
Lunatotriquetral
Scapholunate
Scaphotrapezium
What are the long ligaments
Dorsal and palmar intrinsics
The long ligaments help to ____
Guide motion
What are the ranges for flexion and extension
Flexion is 0-85 with normal values around 70-85
Extension is 0-75
Ranges for ulnar and radial deviation
Ulnar deviation is 0-40 with 35-40 being normal
Radial deviation is 0-20 with normal being 15-20
Where is the axis of rotation for the wrist
Through the capitate
Extension combines with
Radial deviation
Flexion is combined with
Ulnar deviation
Extension and radial deviation can be limited by
Tightness in the palmar radiocarpal ligament
What is the closed packed position for the radiocarpal joint
Extension combines with radial deviation
What is the functional position of the hand and wrist
Wrist 20-30 extension
10 ulnar deviation
Fingers:
Mp-40
Pip-30
Dip-slight flexion
Forces across the ____ reach amounts of ten times greater then the force applied at the _____
Distal carpal row
Fingertips
The central column concept is from what plane of motion
Sagittal
What is the central column concept
Radiocarpal joint: radius and lunate
Mid carpal: lunate and capitate
Carpometacarpal: capitate and 3rd metacarpal
Where does active move to begin in Sagittal plane motion
At the distal carpal row
When do the proximal carpal row move in Sagittal plane motion
When the tension is created by the ligaments crossing the midcarpal joints
Arthrokinematics of extension at the radiocarpal joint
Convex surface of the lunate rolls Dorsally and slides palmarly on the concave surface of the radius
Arthrokinematics of extension at the midcarpal joint
Capitate rolls Dorsally on the lunate and slides palmarly
What is the closed packed position of extension
Palmar ligaments and muscles stretch into tension and stabilize the wrist
Arthrokinematics of flexion at the radiocarpal joint
Convex surface of the lunate rolls palmarly and slides Dorsally on the concave radius
Arthrokinematics of flexion at the midcarpal joint
Convex head of the capitate rolls palmarly and slides Dorsally on the concave lunate
Arthrokinematics of flexion at the scaphoid joint
Rolls similarly to the lunate, displacement restrained by the scapulolunate ligament.
Arthrokinematics of ulnar deviation at the radiocarpal joint
Scaphoid lunate and triquetrum roll ulnarly and slide radially
Arthrokinematics of flexion at the midcarpal joint
Capitate rolls ulnarly and slides radially
What happens at full range of ulnar deviation in regards to arthrokinematics
Triquetrum contacts the articular disc
Hamate compressed against the triquetrum
Proximal row pushed against the styloid process of the radius
_____ helps stabilize the wrist for gripping
Ulnar deviation
Arthrokinematics of radial deviation at the radiocarpal joint
Scaphoid lunate and triquetrum roll radially and slide ulnarly
Arthrokinematics of radial deviation at the midcarpal joint
Capitate rolls radially and slides ulnarly
What is the closed packed position of radial deviation
Full radial deviation
During radial deviation the ____ flexes but the ____ stays neutral due to the extension moment exerted by the triquetrum if all the ligaments are intact
Scaphoid
Lunate
_____ attach distally to the carpus and extend only the wrist
Primary wrist extensors
_____ cross the carpus and attach to the metacarpals of digits and extend the wrist and the digits
Secondary wrist extensors
Where does the axis of rotation pass
Through the capitate bone
What are the primary wrist extensors
Ecrl
Ecrb
Ecu
What are the secondary wrist extensors
Ed
EI
EDM
EPL
All wrist muscles produce torques in what plane(s)
Sagittal and frontal
What is the action of ecrl
Wrist extension and radial deviation
_____ originates proximally at the lateral epicondyle and attaches distally on the second metacarpal
Ecrl
_____ gives a greater moment arm for radial deviation
Ecrl
______ originates on the lateral epicondyle and attaches distally to the third metacarpal
Ecrb
_____ gives a greater moment arm for extension
Ecrb
Injury to_____ will cause decreased grip strength and decreased strength in wrist extension and radial deviation
Ecrl and ecrb
Action of the ecu
Extends and ulnarly deviates the wrist with the forearm supinated, less effective as a wrist extensor with the forearm pronated
_____ assists the TFCC in providing stability to the ulnar side of the wrist
Ecu
What is the main function of wrist extensors
To position and stabilize the wrist during finger activity
Making a fist requires synergistic muscle activity between?
Long finger flexors and wrist extensors
____ is recruited first in the light grip
Moderate is _____
Strong is _____
Ecrb
Ecrl
Ecu
What is the best position for strong grip
In 30-35 degrees of wrist extension and 5 degrees of ulnar deviation. This optimizes the length tension relationship
Why is flexion not the best position to have string grip
With the wrist flexed, the fingers cannot generate any torque because they are in a shortened position and are fighting against passive extensor torque.
What are the primary wrist flexors
Flexor Carpi radialis
Flexor Carpi ulnaris
Palmaris longus
What are the secondary wrist flexors
FDP
FDS
FPL
____ originate on the medial epicondyle and work synergistically during wrist flexion
FCU and FCR
_____ attaches to the palmar surface of the second and third metacarpal and does flexion and radial deviation
FCR
_____ attaches to the pisiform, pisohamate and pisometacarpal ligament, and the 5th metacarpal. Does flexion and ulnar deviation
FCU
______grnerates the most torque of the wrist flexors
FCU
____ anchors the skin and cassia of the hand
Palmaris longus
What are the radial deviatiors
ECRB ECRL FCR EPL EPB APL FPL
______ produce the greatest torque into radial deviation
ECRL and APL
_____ provide stability to the radial side of the wrist augument in the radial collateral ligament
APL and EPB
____ work synergistically as prime generators of radial deviation
ECRL and FCR
_____ is inflammation of degenerative tendinopathy of the APL and EPB (first dorsal compartment).
DeQuervain’s synovitis
Hoe does dequervain’s synovitis occur
Due to then overduse or repetitive strain injury
Dequervain’s is common in who
Mothers with new babies
What is finkelstein’s test
Ulnar deviation with the thumb flexed inside of the fist= severe pain
What are the secondary ulnar deviatiors
FDP
FDS
Ed
