Wrist/Hand Flashcards
Which joints are found in the “wrist”?
Distal R/U, radiocarpal, midcarpal
Radiocarpal joint classification(s)?
Distal radius is concave
Scaphoid and lunate are convex
RC close packed? Resting?
Extension,
Neutral with slight ulnar deviation
RC capsular pattern?
Equal limitation in all directions
Midcarpal joint classification(s)?
Capitate & hamate are convex (Medial distal row of carpals)
Trapezium & trapezoid are concave
● Implication: more movement in medial compartment
Individually, they are each planar joints
Joint as a whole is ovoid, but medial and lateral compartments are opposite shapes
Midcarpal close packed? Resting?
Extension with ulnar deviation,
Neutral or slight flexion with ulnar deviation
List the proximal row of carpal bones.
Scaphoid, lunate, triquetrum, pisiform
List the distal row of carpal bones.
Trapezium, trapezoid, capitate, hamate
Which carpal bone is most frequently fractured?
Scaphoid
Which carpal bone is the largest?
Capitate
Which carpal bone has a distal saddle shape that articulates with the 1st MC?
Trapezium
Which carpal bone has the axis of rotation for all wrist motion pass through it?
Capitate
Which carpal bone increases the moment arm for the flexor carpi ulnaris?
Pisiform
Which carpal bone is most unstable?
Lunate
Describe the Triangluar Fibrocartilage Complex. (What it is made of and roles it plays in the wrist)
TFCC is a disc made of connective tissues (fibrocartilage) and has fibrous attachments to the structures around it.
It allows for motion, increases congruency between distal ulnar and medial carpal bones, absorbs compressive forces (~20%)
Extension AK: assume convex on concave
roll is posterior, slide is anterior
Flexion AK:
roll is anterior, slide is posterior
Ulnar Deviation AK:
roll is medial, slide is lateral
Radial Deviation AK:
roll is lateral, slide is medial
Limitations to Flexion
● Dorsal capsule
● Dorsal Radiocarpal ligament
● Normal end feel is capsular
Limitations to Extension
● Palmar capsule
● Palmar Radiocarpal ligament
● Normal end feel is capsular
Limitations to Radial Deviation
● Scaphoid on Radius
● Ulnar capsule
● Ulnar Collateral ligament
Limitations to Ulnar Deviation
● Radial capsule
● Radial Collateral ligament
How does wrist position affect grip strength at the fingers?
About 30 degrees of wrist extension provides peak grip strength (finger flexion), see figure 7-26 in Neumann. Excessive flexion puts the flexors out of optimal length and lengthens the extensors, which passively limit flexion.
Name the arches found within the hand. What bones/joints comprise these arches?
Longitudinal- structural shape of consecutive bones (along a given ray within the hand)
Proximal Transverse- carpals and CMC joints contribute to this arch
Distal Transverse- arch spread across all of the MCP joints
Which MC’s are more stable? Which are more mobile?
More stable- 2nd and 3rd
More mobile- 4th and 5th
Thumb CMC joint classification in the radioulnar direction:
● the joint surfaces are: concave MC & convex trapezium
● the motions that occur are: flexion/extension (abduction/adduction in plane of the palm)
Thumb CMC joint classification in the anterior/posterior direction:
● the joint surfaces are: convex MC & concave trapezium
● the motions that occur are: abduction/adduction (abduction/adduction perpendicular)
Arthrokinematics of the Thumb CMC Joint:
Abduction perpendicular:
roll is anterior, slide is posterior
Arthrokinematics of the Thumb CMC Joint:
Adduction perpendicular:
roll is posterior, slide is anterior
Arthrokinematics of the Thumb CMC Joint:
● Flexion:
roll is ulnar, slide is ulnar
Arthrokinematics of the Thumb CMC Joint:
● Extension:
roll is radial, slide is radial
Close packed position of thumb CMC:
full opposition
Resting position of thumb CMC:
midway between add/abd perpendicular & midway bettwen flex/ext
Capsular pattern of thumb CMC:
abduction perpendicular most limited, followed by extension
