Overview of the upper limb

Question 1

can you live without a shoulder or elbow

Answer 1

shoulder not that important

Question 2

the shoulder forms…

Answer 2

• Shoulder forms foundation from which the upper limb can move

Question 3

describe the movements that the shoulder allows

Answer 3

• the large range of movement in the shoulder allows the hand to be positioned in a wide area
• they anchor the arm to the trunk
• forms a mobile pectoral girdle this allows a wider range of movement that is possible for the limb
• clavicle and scapula can move to get extra movement

Question 4

what do we depend on the elbow for

Answer 4

washing, dressing, eating and drinking

Question 5

is the elbow very stable yes or no

Answer 5

• Very stable joint

Question 6

what is the hand used for

Answer 6

• Holds objects (dexterity and grasp)
• Touches objects (sense organ)
• Communication

Question 7

where do the muscles that move the fingers originate In

Answer 7

• Partially in the hand – intrinsic – used for fine movement
• Partially in forearm -extrinsic – for power

Question 8

what are the two types of grip

Answer 8

power grip and precisions grips

Question 9

what grips make up power grips

Answer 9

• Cylindrical grip, spherical grip, hook grip, lateral prehension

Question 10

describe the position of the power grip

Answer 10

• All fingers flex around object, thumb curled round to press against acts as safety bar to hold those fingers closed, or meet fingers
- can allow you to hold an object in the palm of the hand

Question 11

what do the hypothenar muscles do in the power grip

Answer 11

• Hypothenar muscles stabilise medial side of palm against handle.

Question 12

what do the wrist extensors do in the power grip

Answer 12

• Wrist extensors active - provide stable base - this gives the tendons a good working range

Question 13

which grip is more primitive, the power grip or precision grip

Answer 13

• the power grip is Most primitive (present in new born babies
- precision grips take longer to be able to perform as they are more complicated as they require a combination of movements - it develops at around 9 months

Question 14

what power grip is the thumb not involved in

Answer 14

• Thumb isn’t aways involved when you are carrying the handle of a bag this is called a hook grip

Question 15

describe the precision grip

Answer 15

• Object held between tip of thumb and 1,2, or 3 fingers

Question 16

what re the muscles that are involved in the precision grip

Answer 16

• Intrinsic muscles involved, co-operate with long flexors and extensor muscles
• Flexions and extension – combination of movements, therefore it takes time to develop and be able to perform these types of movements

Question 17

what grip is non prehensile

Answer 17

Hook grip is non prehensile whereas every other movement is prehensile

Question 18

the radial nerve is the ..

Answer 18

• This is the biggest terminal branch of the brachia’s plexus

Question 19

what does the radial nerve innervate

Answer 19

• It innervates all the extensor muscles of the upper limb

- It also innervates anything in the posterior compartment

Question 20

where does the radial nerve run

Answer 20

• Runs between the medial and lateral head of triceps, it runs between the insertion points next to the humerus this is the spiral group – this is also the radial group
• It then goes into the anterior part of the elbow and back into the posterior part of the forearm

Question 21

what is another word for spiral group

Answer 21

radial group

Question 22

what is the most common cause of radial nerve damage

Answer 22

• Most common region where the radial nerve gets injured is a midshaft humerus fracture – goes along the point where the radial nerve goes along the bone

Question 23

what is a clinical presentation of radial nerve damage

Answer 23

wrist drop

Question 24

what is cause of wrist drop

Answer 24

• compression or damage to the radial nerve
  • No extension of wrist and digits - unopposed action of FDS and FDP
  • Only weak flexion at DIP joint from intrinsic muscles of hand
  • Sometimes they can extend the elbow, depends on where the radial nerve comes up the triceps – may not completely lose extension of the elbow
• not able to form a power grip as this needs an extended grip

Question 25

what is the cause of Saturday nigh palsy

Answer 25

* Radial nerve in armpit or upper arm is compressed or stretched * Usually as a result of falling asleep with arm hanging\ * This can give you wrist drop

Question 26

is Saturday nigh palsy permanent or not

Answer 26

• This is not permenanet and will once the compression has eased and the blood supply is better it will regrow and sensory innervtion will come back

Question 27

what is the cause of radial nerve palsy in newborns

Answer 27

- Secondary to prolonged pressure on inferior arm by pelvic brim - Wrist drop - Inability to extend thumb and MCP of all digits - Weak extension of the elbow

Question 28

when is radial nerve palsy in newborns reversed

Answer 28

- After about 2 weeks to 2 months they gain back innervation again

Question 29

what does the median nerve innervate

Answer 29

- Innervates the antieror plexus and goes to the thenar muscles at the base of the thumb

Question 30

where does the median nerve run

Answer 30

- This is in the anterior compartment - Doesn’t do anything in the arm - Runs with brachial artery - Goes into the forearm

Question 31

where can you injure the median nerve

Answer 31

- Can injure it at the elbow where it becomes superficial – supercondyle fracture to the humerus, humerus and proximal region has moved into the humerus – stretch or lacterate the medial nerve high - Everything distal to that point is lost

Question 32

what happens if you have high median nerve damage

Answer 32

- Loss of flexion of MCP digits 2-3 - Loss of flexion of PIP in digits 1-3 - Loss of DIP flexion digits 2-3 - Weak PIP flexion of digits 4-5 - Can flex DIP of digits 4-5 - Because ulnar nerve innervates medial FDP and FCU – can still flex fingers 4 and 5 – little finger and ring finger

Question 33

what is the hand caused when it has damage to the median nerve

Answer 33

hand of benediction

Question 34

how can you test for damage to the median nerve

Answer 34

- ask the patient to make a fist - then you can see which area of the hand is being effected - then you get the hand of benedicition – thumb index finger and middle finger do not move

Question 35

what causes low median nerve damage

Answer 35

carpal tunnel syndrome

Question 36

how symptoms are caused with low median nerve damage

Answer 36

- progressive loss of co-ordination and strength in thumb - causes compression to the median nerve all the long flexor muscles can still work, - can make a thirst but the thumb doesn't work very much, loose ability to oppose the thumb

Question 37

what is the most common site of nerve lesions to the upper limb

Answer 37

– medial epicondyle of humerus therefore it effects the ulnar nerve

Question 38

what does damage to the ulnar nerve cause

Answer 38

claw hand

Question 39

what muscles are effected in the ulnar nerve damage

Answer 39

``` – flexor carpi ulnaris, – medial half of FDP, – medial two lumbricals, – all interossei (palmar and dorsal) – adductor pollicis ```

Question 40

what does the ulnar nerve innervate in the hand

Answer 40

– all the instrinsic muscles of the hand except the thenar muscles innervated by the ulnar nerve

Question 41

what is more severe in an ulnar nerve injury a high lesion or low lesion

Answer 41

low lesion

Question 42

describe what happens with a high lesion in an ulnar nerve injury

Answer 42

both intrinsic hand and FDP weak so clawing milder

Question 43

describe what happens with a low lesion in an ulnar nerve injury

Answer 43

only intrinsic muscles weak means clawing is more severe

Question 44

what happens in cubital tunnel syndrome

Answer 44

- Cubital tunnel syndrome – high all muscle lost

Question 45

what happens in guyot's anal syndrome

Answer 45

- Guyon’s anal syndrome – low – FDP pulls digit 4 and 5 in flexion

Question 46

what are the presentations of ulnar nerve lesions

Answer 46

- Muscle atrophy of the intrsic muscles of hand - Most obvious in 1st dorsal interosseus web, thenar not effected - Even in long term the thenar muscle is still there - Loose intrinsic muscles for precisois grip - Muscle atrophy of FCU and medial FDP

Question 47

how do you test motor control of the hand

Answer 47

- Test extension and the power of exntesion in the wrist - Median nerver – making a this and what the thumb does – opposition and flexion of the thumb - Ulnar – abduction and adduction – ask them to hold a piece of paper between two fingers or ask them to spread fingers apparat and resist you pushing them in