anatomy of hand and wrist

Question 1

what are the 3 types of grips

Answer 1

hook
power
precision

Question 2

what is the difference between hook, power and precision grip

Answer 2

hook = flexion of 2-4 digits and thumb is used as stabiliser (doesnt provide power)

power = flexion of 2-4 digits with thumb used for strength/power / (palmar opposition grasp in which all digits are flexed around the object to provide high stability)

precision = pinch grip (tips of fingers touching)

Question 3

what movements occur at the wrist

Answer 3

• hyper-extension
• extension
• flexion
• radial deviation
• ulnar deviation

Question 4

what movements occur at the digits

Answer 4

• flexion
• adduction
• abduction
• opposition of thumb

Question 5

what is the connective tissue that forms the roof of the carpal tunnel

Answer 5

• flexor retinaculum

Question 6

the carpal tunnel contains how many tendons

Answer 6

9

Question 7

what causes carpal tunnel suyndrome

Answer 7

compression of the medial nerve within the carpal tunnel

Question 8

what 2 arteries anastomose to form the superficial and deep palmer arterys

Answer 8

radial and ulnar artery

Question 9

what is the Allens test

Answer 9

• tests for adequate anastomoses between radial and ulnar arteries
• compress both radial and ulnar arteries at wrist
• release pressure from one or the other and determine the filling pattern of hand
• if there little connection between deep and superficial palmer arteries, only the thumb and lateral side of index finger will fill with blood when pressure on radial artery alone is released

Question 10

why is the skin on the dorsal side of your hand easier to pinch

Answer 10

• the palmar skin is connected to a thick fascia known as
• palmar aponeurosis

Question 11

what is the role of palmar aponeurosis

Answer 11

protects underlying muscle compartments and fans out distally into 4 digital rays which become the fibrous digital sheaths

Question 12

falling onto an outstretched hand causes what type of wrist frature

Answer 12

colles fracture

• fracture of distal radial metaphysical with Doral angulation and impaction
• no involvement of articular surface

(wrist breaks on palmer side)