Upper Limb - Hand Flashcards
What are the CMC joints?
joints between the carpal bones of the wrist and the metacarpals of the hand
Which is the most freely moving CMC joint? Why is this important?
1st CMC - the thumb
allows the thumb to oppose all the fingers giving humans greater dexterity than any other
What type of joint is found at the 1st CMC?
a saddle joint
What are inter metacarpal joints?
irregular articulations formed between the proximal ends of adjacent metacarpals
What are the MCP joints?
condyloid joints formed by the rounded distal heads of the metacarpals and the concave proximal ends of the phalanges
What do the MCP joints form on the surface of the hands?
knuckles
What stabilises MCP joint?
strong collateral ligaments
What movements are allowed at the PIP and DIP joints?
flexion and extension
How many IP joints does the thumb have?
1
How much flexion is permitted at the proximal hand joints?
100-110 degrees
How much deletion is permitted at the distal joints of the hand?
90 degrees
To extend fingers beyond neutral, what must individuals have?
lax ligaments
How much flexion extension is permitted at the thumb MCP?
30-90 degrees felxion
15 degrees extension
How much flexion extension of the thumb is possible?
15 degres flexion
20 degrees extension
What plane does thumb flexion extension happen in?
the plane of the palm
How much abduction of the thumb is possible?
60 degrees
Is rotation of the thumb possible?
yes - slightly
some rotation is involved when opposing the little finger
Which muscle originates form the anterior aspect of the ulna and inserts onto the distal phalanges, allowing flexion of the DIPs?
flexor digitorum profundus
What happens to tendons as the wrist changes position?
functional lengths of the tendons change in different wrist positions
