Movement lecture 2: Upper limb - shoulder

Question 1

Where is the glenohumoral joint located?

Answer 1

Between glenoid fossa of scapula and head of humerus..

Question 2

Which bones constitute the pectoral girdle?

Answer 2

Clavicle, scapula and manubrium.

Question 3

Which muscles attach the scapula to the trunk and what is their function?

Answer 3

Rhomboids, levator scapulae, trapezius and serratus anterior. Stabilise the pectoral girdle.

Question 4

What would you seen in the case of long thoracic nerve damage?

Answer 4

Winged scapula (paralysed serratus anterior - scapula no longer pulled towards chest wall) medial border and inferior edge very obvious. Seen in penetrating stab wounds, neuritis, poor chest drain insertion.

Question 5

What can lead to calcification of the bursa (calcific bursitis)?

Answer 5

Inflammation e.g. bursitis

Question 6

What is painful arc syndrome?

Answer 6

• Calcific bursitis
• Typically develops in males >50 years
• Caused by inflammation e.g. after excessive use of glenohumeral joint
• Pain during 50-130° of abduction – painful arc
• Subacromial bursa is in contact with the inferior surface of the acromion

Question 7

Why can dislocation of the glenohumeral joint cause damage to the axillary nerve?

Answer 7

The axillary nerve passes inferior to the humeral head and winds round the surgical neck of the humerus. Inferior dislocation can damage the nerve.

Question 8

Which nerves make up the brachial plexus

Answer 8

Musculocutaneous	C5-C7
Median			C6-T1
Ulnar 			C7-T1
Axillary			C5-C6
Radial			C5-T1

Question 9

Why might abduction at the glenohumeral joint be impaired?

Answer 9

Supraspinatus paralyzed

• Suprascapular nerve C5,6
• Scapular fracture
• In this case patient can produce first 10-15 degrees of abduction by leaning to one side and letting joint abduct passively

Deltoid paralyzed

• Axillary nerve C5,6 (terminal branch of posterior cord of brachial plexus)
• Shoulder dislocation
• Fracture of surgical neck of humerus

Question 10

What is quadrangular space syndrome?

Answer 10

• Transient blockage of the posterior humeral circumflex artery and axillary nerve
• Typically occurs when the arm lies in a position of abduction, extension, and external rotation
• Patients note shoulder pain and paraesthesia down the arm
• Often associated with fibrotic bands in quadrangular space
• Uncommon condition that mostly affects athletes who perform overhead movements e.g. tennis