Acromioclavicular Joint

Question 1

AC joint is;

Answer 1

a synovial joint between the acromion process of scapula and the distal end of the clavicle
(fibrocartilaginous disc is interposed between the two articular surfaces)

Question 2

Innervation:

Answer 2

provided by the lateral pectoral and suprascapular nerves

Question 3

Degrees of freedom?

Answer 3

3 degrees of freedom for very small rotational movements

Question 4

physiologic movements

Answer 4

upward & downward rotation of the scapula about and A-P axis at the AC joint

Question 5

Sagittal plane movement:

Answer 5

rotational adjustments
anteroposterior tipping (tilt) at the AC about the mediolateral axis
occur during scapular elevation and depression

Question 6

horizontal plan movement:

Answer 6

adjustments about the vertical axis

motions occur during scapular protraction and retraction

Question 7

Ligamentous support

Answer 7

Superior and Inferior AC Ligaments

Coracoclavicular ligaments

Question 8

Superior and Inferior AC ligaments

Answer 8

control movement of the acromion on the clavicle during motion at the AC joint

Question 9

Coracoclavicular ligaments

Answer 9

Trapezoid fibers
Conoid fibers
-important for controlling upward scapular rotation during humeral elevation
-SHOULDER SEPARATION

Question 10

shoulder separation

Answer 10

medial displacement of the acromion under the clavicle