Wrist And Hand Flashcards
What jts are included in the wrist/hand complex
Distal radioulnar Wrist complex (radiocarpal and midcarpal) Carpometacarpal Metacarpophalangeal Interphalangeal
T/F The structure and biomechanics of the wrist and hand are consistent between people
False: vary tremendously
Subtle differences in structure of the hand/wrist can….
Produce differences in the way of a given function
Describe the wrist jt (complex)
A biaxial, condyloid jt between
Radius with scaphoid, lunate and triquetrum (radiocarpal)
Scaphoid, lunate, and triquetrum with trapezium, trapezoid, capitate, and hamate (midcarpal)
What are the benefits of a the 2 jt system in the wrist
Permits large ROM w less exposed articular surfaces and tighter jt capsule
Less tendency for a pinch during extremes of motion
Allows for flatter multi-jt surfaces (more capable to withstand imposed pressures)
Describe the proximal component of the radiocarpal jt
Concave surfaces of radius and adjacent art. Disc
Describe the distal component of the radiocarpal jt
Convex proximal surface of scaphoid and lunate
Describe the medial compartment of the midcarpal jt
Convex head of capitate and apex of hamate withdrawal the concave recess of scaphoid, lunate, and triquetrum
Describe the lateral compartment of the midcarpal jt
Convex distal pole of the scaphoid with concave proximal trapezium and trapezoid
Though wrist ligaments are small and difficult to isolate, they are essential for
Maintaining intercarpal alignment
Transferring forces within and across carpals
The triangular Fibrocartilage complex at the wrist functions to
Bind distal ends of the ulna and radius while allowing the radius to rotate around the ulna
Reinforces ulnar side of the wrist and transfers compression force
Passive structures of the wrist jt include
Triangular fibrocartilage complex
Extensor retinaculum
Palmar carpal ligament
The extensor retinaculum prevents…
Bowstringing with active movement of the wrist
The palmar carpal ligament is analogous to
Extensor retinaculum
Carpal tunnel syndrome is when
The median nerve is compressed or mechanically stressed
Factors that contribute to CTS
overcrowding
Excessive mechanical stress
Fibrotic changes of connective tissue
Osteokinematics of the wrist jt
Flex/ext
Radial/ulnar dev
Describe the convex-concave relationship in the wrist
Convex on concave at radiocarpal and midcarpal jts
Arthrokinematics of flexion at the wrist
Anterior roll posterior glide
Arthrokinematics of ext at the wrist
Posterior roll anterior glide
Arthrokinematics of radial deviation
Lateral roll, medial glide
Arthrokinematics of ulnar dev
Medial roll lateral glide
Describe the closed packed position of the wrist
Full ext with radial dev
Describe the open packed position for the wrist
Neutral flex/ext with slight ulnar dev
Capsular pattern for the wrist
Flexion=extension, slight radial and ulnar dev
What is the main function of the wrist extensors
Position and stabilize activities that require active flexion of the digits (counterbalance wrist flexor torque)
Why does 30 degrees of wrist extension allow for max grip
This position optimizes the length-tension relationship of extrinsic finger flexors
What muscles act synergistically for oppose ulnar and radial dev during active wrist flexion
FCU and FCR
Peak wrist flexion torque is at
40 degrees of wrist flexion
What are the jts of the hand
Carpometacarpal
Metacaropophalangeal
Interphalangeal (PIP, DIP)
Describe the CMCs
Articulates 1st - 5th metacarpals with the trapezium, trapezoid, capitate, and hamate
1st: saddle jt
2-5: plane jt
What are the passive structures of the 1st CMC jt?
Anterior oblique First intermetacarpal Posterior oblique Ulnar collateral Radial collateral
What are the passive structures of the 2nd-5th CMC jts?
Dorsal Carpometacarpal lig
Palmar Carpometacarpal lig
Dorsal intrmetacarpal lig
Palmar intermetacarpal lig
What are the Osteokinematics of the 1st cmc jt
Flex/ext
Abd/add
Opp/rep
Arthrokinematics of abd at the 1st cmc jt
Anterior roll posterior glide
During abd/add at the 1st cmc jt, the _____________ articular surface of the 1st metacarpal moves on the __________ trapezium
Convex
Concave
Arthrokinematics of add at the 1st cmc jt
Posterior roll anterior glide
Arthrokinematics of flexion of the 1st cmc jt
Medial roll and glide
Describe the concave-convex relationship of flex/ext at the 1st cmc jt
Concave surface of metacarpal moving on convex diameter of the trapezium
Arthrokinematics of extension of the 1st cmc jt
Lateral roll and glide
Opposition/reposition of the 1st cmc j is a combination of
Flex/ext and add/abd
Arthrokinematics of opposition at the 1s cmc jt
Abduction , flexion
Osteokinematics of reposition at the 1st cmc jt
Adduction and extension
Osteokinematics of cmc jts 2-5
Flexion /ext
What is the open packed position of the 1st cmc jt
Mid flex/ext and min abd/add
Where is the closed packed position of the 1st cmc jt
Full opposition
Capsular pattern of the 1st cmc jt
Abd
Closed packed position of cmc jts 2-5
Full flexion
Open packed position of cmc jts 2-5
Mid flex/ext
Osteokinematics of metacarpophalangeal jt
Flex/ext
Abd/add
Circumduction (accessory motion)
Convex-concave relationship in mcp jts
Concave surface of phalanx moving on convex metacarpal head
Arthrokinematics of flexion at the mcp jts
Anterior roll and glide
Arthrokinematics of extension at the mcp jts
Posterior roll and glide
Arthrokinematics of abd at the mcp jts
Roll and glide away from the 3rd digit
Arthrokinematics of add at the mcp jts
Roll and glide toward the 3rd digit
Closed packed position at the mcp jt
Full flexion
Open packed position of the mcp jts
Slight flexion
Capsular pattern of the mcp jts
Flexion=extension
Interphalangeal jts are what type of jt
Hinge jt
Mcp jts are what type of jts
condyloid
Convex-concave relationship in the interphalangeal jts
Concave on convex
Arthrokinematics of flexion at IP jts
Roll palmar glide palmar
Arthrokinematics of extension at IP jts
Roll dorsal, slide dorsal
Closed packed position of IP jt
Full ext
Open packed position of IP jts
Slight flex
Capsular pattern of IP jt
Flexion= ext
The fibrous digital sheath embeds ____________. What does this do?
Flexor pulleys
Prevents bowstringing of the tendons with contraction of extrinsic finger flexors
Bowstringing of flexor tendons can be observed in some elite rock climbers due to
Overstretching or severing of pullys
What occurs secondary to tenosynovitis, does not impact gliding action, and may develop a nodule with prolonged tenosynovitis which can wedge into the sheath and block movement?
Trigger finger
How do the extensor tendons differ from flexor tendons
Distal to the wrist they lack a digital sheath or pulley system and tendons become integrated into fibrous expansion
The most prominent feature of the extensor mechanism is the ______________. What does this do?
Dorsal hood
Stabilizes ED tendon, form sling that assists ED to extend MCP jt
Transfers force from lumbricals/interossei to lateral bands to assist with DIP/PIP extension