Hand Flashcards
_____ is the principle vehicle of complex and precise motor activity
The hand
The _____ has a strong functional relationship with the eyes
Hand
What is the function of the upper extremity
Position the hand for optimal function
The proximal transverse arch is made by the ____
Distal row of carpal bones
What arch passes through the mcp joints
Distal transverse arch
What arch follows the shape of the 2nd and third rays
Longitudinal arch
_____ is the “rigid tie beam”
Longitudinal arch
_____ creates a concavity of the palmar surface of the hand
Longitudinal arch
______ allows the hand to hold and manipulate objects of various shapes ans sizes
Longitudinal arch
_____ articulation between the distal row of carpal bones and the base of the 5 metacarpal bones
Carpometacarpal joints
How many degrees of freedom do the Cmc joints have
2 degrees of freedom
Flexion/extension
Abduction/adduction
_______ Cmc joints are rigid stable central pillars
And what ones are mobile
2 and 3
1 4 and 5
All Cmc joints are surrounded by _____ and strengthened by ____
Articular capsules
Ligaments
What ligaments strengthen the Cmc joints
Dorsal
Palmar
Interosseous
_____ cmc joint has jagged interlocking surfaces, strong ligamentous support, and permit very little movement
2 and 3
What is the joint structure of 4 and 5 Cmc joints
Convex metacarpal base, concave hamate
What is functional about the 4 and 5 Cmc joints
It improves effectiveness of grasp
Enhances the functional interaction with opposable thumb
______ is the articulation formed between the convex metacarpal and concave proximal phalanx (P1)
Metacarpophalangeal joints or mcp
What are the degrees of freedom at the mcp joints of the digits
2 degrees of freedom
Flexion extension
Abduction
Adduction
What is the axis of rotation in the mcp finger joints
Passes through the metacarpal head.
What is in the capsule of each mcp joint
Pair of radial and ulnar collateral ligaments
Volar plate
_____ is oblique palmar direction from metacarpal to proximal phalanx (2 distinct parts)
Collateral ligaments
The collateral ligaments are more taut in _______
Flexion than extension
What is the function of the Volar plate ligament
Strengthens the mcp joint
Prevents hyperextension
The Volar plate is a dense _____ structure found in every mcp Joint
Fibrocartilage
How would an mcp joint dislocate
Rupture of the Volar plate at its proximal attachment
Simple vs complex mcp joint dislocation
Cannot be reduced because Volar plate or other structures become entrapped within the joint.
_____ is the attachment between Volar plates and the mcp joint
Deep transverse metacarpal ligaments
What ligament binds the fourth and fifth metacarpals
Deep transverse metacarpal ligaments
what limits the distance by which metacarpal heads may separate
Deep transverse metacarpal ligaments
There is substantial accessory motion in _____ joints
Mcp
What is good about substantial accessory motion in the mcp joints
Permits fingers to conform to the shapes of objects
Increases grasp control
Mcp rom increases gradually from digits 2-5 from _____ to _____ mcp joint flexion
90-115
Where is the greatest rom flexion of the mcp joints
Ring finger and small finger
Describe the arthrokinematics of the mcp joint of the fingers
Concave phalanx moving against convex metacarpal
Explain the arthrokinematics of active mcp finger joint flexion (FDP)
Proximal phalanx rolls and slides volarly
Passive tension increases in the dorsal capsule and the collateral ligaments are taut
______ of the mcp finger joints are stabilizing the joints during flexion and useful during grasp
Active mcp joint flexion (FDP)
Explain the arthrokinematics of active mcp finger joint extension (co-activation of ED and intrinsic muscles of the finger)
Proximal phalanx rolls and slides Dorsally
During ______ the Volar plate elongates to support the head of the metacarpal
Active mcp finger joint extension
_______ creates slack in the radial collateral ligament of the mcp finger joints
Active mcp joint extension
How is the mcp finger joint positioned to heal after trauma
70 degrees of flexion to place a stretch on the collateral ligaments to prevent mcp joint contracture
Explain the arthrokinematics of active mcp finger joint adduction
Proximal phalanx rolls and slides radially
_____ muscle directs abduction at mcp finger
First interossei
What are the collateral ligaments doing when mcp finger joints are abductiing. How does this stabilize the joint
Ucl is taut
Rcl is on slack
This stabilizes the joint radially
How do the pip joints articulate
Articulation between the concave middle phalanx surface and the convex proximal phalanx
_____ joint articular surface appears as a tongue in groove articulation. It guides flexion and extension as it restricts axial rotation
Pip joint
Within the capsule each pip joint is reinforced by _____.
Radial collateral ligament
Ulnar collateral ligament
Accessory motion of the collateral ligament in pip joints reinforces ____
The Volar plate
______ limits pip joint hyperextension via check rein ligaments
Collateral ligaments
How will the pip joints be placed if they need to heal after dis location
15-20 degrees of flexion for the Volar plate to heal
Pip joint dislocation can cause…
Partial or complete damage to the collateral ligaments and central slip or Volar plate
_____ articulation between the bases of the concave distal phalanx and convex middle phalanx.
Dip
How do the pips and dips differ
Dips don’t have the check rein ligaments
Describe active pip joint flexion
Concave middle phalanx rolls and slides volarly by the extrinsic finger flexors (FDS and FDP)
Axis of rotation for pip joint flexion
Medial lateral direction through the convex joints
How is the thumb oriented in anatomical position
Medially and anteriorly. It is almost rotated 90 degrees in relation to the fingers for optimal prehension
What is the Cmc thumb joint arthrology
Articulation between the trapezium and the base of the first metacarpal. It’s saddle shaped
Explain the saddle shape
Articular surface is convex in one direction and concave in the other.
Shape of the trapezium and 1st metacarpal (convex/concave)
Trapezium: Concave longitudinally and convex transversely
Base of the 1st metacarpal is convex longitudinally and concave transversely
What are the degrees of freedom for the Cmc thumb joint
2
Flexion extension
Abduction adduction
Opposition reposition
What are the ligaments of the Cmc thumb joint
Rcl Ucl Anterior oblique ligament Posterior oblique ligament 1st inter metacarpal
_____ is the most important ligament for thumb stability and resists dorsal translation of Cmc on the trapezium
Anterior oblique ligament
Arthrokinematics of thumb Cmc joint flexion
Concave metacarpal rolls and slides medially on the convex trapezium.
Cmc thumb joint flexion does what to the Rcl
Elongates
Arthrokinematics of thumb Cmc joint extension
Concave metacarpal rolls and slides laterally on the convex trapezium. This stretches the Ucl and anterior oblique ligament. There is also slight metacarpal lateral rotation on the groove on the trapezium
What is the axis of rotation of the Cmc joint of the thumb
Passes thorough the head of the metacarpal bone
Arthrokinematics of Cmc thumb joint abduction
Convex metacarpal surface rolls volarly and slides Dorsally on the concave trapezium. Stretching the adductor pollicis and most ligaments
Arthrokinematics of Cmc thumb joint adduction
Convex metacarpal rolls Dorsally and slides volarly on the concave trapezium
What are the two phases of opposition
Thumb metacarpal abducts
Metacarpal flexes and medially rotates across the palm and towards the small finger.
______ guides and rotates the thumb metacarpal
Opponens pollicis
_____ is the articulation between concave proximal phalanx and convex metacarpal
Thumb mcp
What are the Osteokinematic differences between thumb and finger mcp joints
One degree of freedom–flexion extension
Arom and prom at mcp joint significantly less
Active abduction adduction are limited due to collateral ligament structure and bone congruity
What is the axis of rotation for the thumb ip joint
Anterior posterior direction, through the convex joints
Flexion of the thumb is powered by ___ and ____
FPL and fpb
Hand movements cannot be achieved without _____. It requires _____ contraction of the muscles that cross the wrist.
Wrist stabilization
Isometric contraction
______ supplies all the extensors of the wrist and digits with proximal attachments in the forearm and the lateral epicondyle
Radial nerve
_____ supplies most of the flexors of the wrist and digits with proximal attachments on the forearm and the medial epicondyle
Median nerve
_____ supplies most of the small muscles in the hand.
Ulnar nerve
What are the exceptions to the innervations
Half of FDP and lumbricals supplied by the median and ulnar nerves
Ulnar nerve supply to FCU
Median nerve supply to the thenar muscles
_____ flexes the ip joint of the thumb
FPL
_____ exerts flexion torque at mcp and Cmc joints
FPL
Extrinsic flexor tendons travel to their distal attachment via ____
Fibrous sheath tunnels
Embedded within each digital sheath there are bands of tissues called ____
Pulleys
______ is inflammation of flexor tendons and surrounding synovial membranes
Stenosing tenosynovitis
Stenosing tenosynovitis is also known as
Trigger finger
_____ stabilize tendons relative to underlying joints
Flexor pullys
What are the flexor pulleys
5 annular pulleys (A1-A5)– A2 and A4 are the main ones
3 cruciate pulleys (C1-C3)
What is the tenodesis action
As the wrist actively extends, digits automatically flex due to the increased passive tension of the extrinsic flexor muscles.
_____ are the interconnections between ED tendons
Juncturae tendinae
______ do isolated finger extension of digit 4 and 5
Juncturae tendinae
____ works independently in wrist extension if you do extension with a fist
Extensor indicis
ED is firmly anchored to the dorsal aspect of the mcp joint by the ____
Sagittal bands
_____ travel from the ED tendon Dorsally to the Volar plate volarly
Sagittal bands
___ transmit extension power of the ED to the mcp joint
Sagittal bands
_____ stabilize the ED over the dorsum of the hand
Sagittal bands
What is the central feature of the extensor mechanism
Dorsal hood
_____ consists of a triangular sheet of thin aponeurosis
Dorsal hood of extensor mechanism
Multiple attachments of the extensor mechanism into the phalanges allow the _____ to transfer extensor force distally throughout the entire finger.
Extensor digitorum
_____ flexes the ip and mcp joint
FPL
_____ is the only muscle that flexes the thumb ip joint
FPL
What generates a firm grip
FDS and FDP
_____ extends the ip, mcp, and Cmc joint
EPL
_____ extends the mcp and cmc joints
EPB
_____ abducts the Cmc joint
APL
____ flexes the mcp and Cmc joint of the thumb
Flexor pollicis brevis
_____ opposes the thumb for pinch and grasp against fingers
Abductor pollicis brevis
_____ opposes and rotates the thumb medially towards the fingers. It flexes and abducts the Cmc joint
Opponens pollicis
What is the dominant muscle at the Cmc joint
Adductor pollicis
_____ pass volarly to the deep transverse carpal ligament
Lumbricals
______ pass dorsal to the deep transverse carpal ligament
Interossei
Explain the early phase of finger extension
ED extends the mcp joint
ED and intrinsics are primary finger extensors
Explain the middle phase of finger extension
Intrinsic muscles effect in ip joint extension
Direct: proximal pull of the extensor mechanism
Indirect: flexion torque at the mcp joint
Explain the late phase of finger extension
Muscle activation continues through full finger extension
Explain the phases of finger flexion
Early phase: FDP, FDS, and interossei actively flex ip joints pulling the extensor mechanism distally
Late phase: muscle activation continues through full flexion. Lumbricals remain inactive but passively assist. ED decelerates mcp flexion with consistent EMG activity when the hand is closing. The ECRB stabilizes the wrist in slight extension.
Where is the oblique retinacular ligament
Palmar side of the pip joint to the dorsal side of the dip joint
What happens to the oblique retinacular ligament when ED and intrinsics initiate extension of the pip joint
It stretches, and passive tension is transferred distally to extend the dip joint
What is rheumatoid arthritis
Autoimmune disease
Chronic systemic inflammatory disorder
Primarily attacks the synovial joints–> chronic synovitis
_____ reduces tensile strength of the connective tissue s
Synovitis
What happens in rheumatoid arthritis
Mechanical integrity of the joint is destroyed –> joints become misaligned, unstable and frequently deformed.
_____ is the collapse of multiple interconnected joints in alternating directions
Zigzag deformity thumb
What does zigzag deformity involve
Cmc flexion and adduction
Mcp hyperextension
Ip flexion
How can you tell you have volar dislocation
When the fingers flex during grip, FDP transmits force palmarly away from the mcp joint. Proximal phalanx translates palmarly causing mcp dislocation
_____ is excessive ulnar deviation and translation of the proximal phalanx, ulnar directed forces generated by the thumb. Flexion torque causes Volar dislocation, in addition to this
Ulnar drift
_____ is a huge trauma to Volar plates of he digits. There is a weakened or attenuated Volar late at the pip joint. Lateral bands bowstring Dorsally away from the joint axis of rotation.
Swan neck deformity
What does swan neck deformity look like
Increasing moment arm of the pip joint extension causing hyperextension and dip joint flexes because of increased FDP passive tension placed across the pip joint
What is the primary cause of boutonnière deformity
And normal displacement of the bands of the extensor mechanism at the pip joint.
What causes boutonnière deformity
Chronic synovitis which causes a rupture of the central slip. Lateral bands slip volarly to the axis of rotation.
What does the boutonnière deformity look like
Forces cause flexion at the pip joint
Dip joint hyper extends due to the increased tension of the stretched lateral bands.
