Living anatomy of the upper limb

Question 1

What limb movements cause rotation at the sternoclavicular joint?

Answer 1

Most movements will cause rotation at this joint, which includes abduction, adduction,
flexion and extension of the arm, as well as elevation, depression, protraction and
retraction of the scapula.

Question 2

In a dislocation of the acromioclavicular joint, which of the two bones would lie uppermost?

Answer 2

The clavicle usually lies uppermost because the most frequent cause of dislocation of
this joint is a direct blow to the acromion/fall onto the point of the shoulder (e.g. during
contact sports such as rugby). This frequently leads to both rupture of the
acromioclavicular and coracoclavicular ligaments, the latter of which leads to elevation of
the clavicle.

Question 3

Describe the movement of the scapula during abduction of the arm

Answer 3

Lateral rotation of the inferior angle

Question 4

Can all the movements at the shoulder joint be performed if the scapula remains fixed?

Answer 4

No

Question 5

How would you test lateral and medial rotation at the shoulder joint?

Answer 5

The action of placing both hands behind the head is a good test of lateral rotation on the
two sides. Actively placing both hands on the back between the scapulae tests medial
rotation. With the arm abducted to 90 and the elbow flexed to 90, moving the hand and
forearm upwards and downwards tests lateral and medial rotation respectively

Question 6

What are the actions of the deltoid

Answer 6

Deltoid is a powerful abductor of the arm. The anterior fibres also flex and medial rotate
the arm, whereas the posterior fibres extend and laterally rotate arm

Question 7

What muscles cause flexion at the elbow joint when the forearm is (a) supinated (b) pronated and (c)half pronated

Answer 7

(a and b) biceps and brachialis

(c) brachioradialis

Question 8

What is the position of the radius in relation to the ulna when the forearm in
supinated and pronated?

Answer 8

Radius and ulna lie parallel to each other when supinated. The radius crosses over the
ulna when pronated.

Question 9

What movements can be performed at the radiocarpal (wrist) joint?

Answer 9

Flexion, extension, abduction, adduction, circumduction

Question 10

Name the tendons that form the anatomical snuffbox

Answer 10

Extensor pollicis longus, extensor pollicis brevis and abductor pollicis longus

Question 11

Which muscles form the thenar eminence?

Answer 11

Abductor pollicis brevis, flexor pollicis brevis and opponons pollicis

Question 12

What is the function of the dorsal interossei muscles?

Answer 12

To abduct the digits

Question 13

Comment on the position of the wrist joint and the joints of the hand in a
precision grip.

Answer 13

In a precision grip, the wrist joint is neutral position or slightly extended. The
metacarpophalangeal joints are flexed and the interphalangeal joints extended. The wrist
is held stable by the long flexor and extensor muscles. The intrinsic muscles of the hand
(i.e. the lumbricals) flex the metacarpophalangeal joints and extend the interphalangeal
joints.

Question 14

Comment on the position of the wrist joint and the joints of the hand in a power
grip

Answer 14

In a power grip, the wrist is extended and the joints of the fingers tightly flexed around the
instrument being held. The extension of the wrist by the extensors increases the distance
over which the flexors act, therefore enabling a more complete/stronger muscular
contraction