GH joint, Biomechanics, Conditions Flashcards
During what OSTEOKINEMATIC motion(s) do the following ARTHROKINEMATIC motions occur in the GH joint?
- Spin
- Inferior glide
- Superior glide
- Posterior glide
- Anterior glide
- flexion/extension
- abduction
- adduction
- internal rotation
- external rotation
What is the capsular pattern of the shoulder from most restriction to least?
ER > Abd > (Flex) > IR
What is the close packed position of the shoulder?
loose packed position?
close: 90° of abduction with full ER.
loose: 30° of abduction, flexion, and internal rotation.
Which ways does the glenoid fossa point?
laterally, anteriorly, and slightly superiorly
The axis of the head and shaft of the humerus form an angle of how many degrees in the frontal plane? Chondyles form an angle of how many degrees in the transverse plane?
frontal: 135-150°
transverse: 30-45° posteriorly
ext. rotation tightens which of the 3 parts of the GH ligament? int. rotation? abduction?
ext. rotation: all 3
int. rotation: all 3
abduction: middle & inferior (via “sling” effect)
The anterior band of the coracohumeral ligament attaches to the humerus with what tendon? posterior band?
anterior: to lesser tuberosity with subscapularis tendon.
posterior: to greater tuberosity with supraspinatous tendon.
extension tightens which band of the coracohumeral ligament? flexion?
extension: primarily anterior band
flexion: primarily posterior band
What pair of muscles initiates GH abduction? GH flexion? Scapular rotation (later in abd/flex)? Scapular add (in ext. rotation)? Scapular abd (in int. rotation)?
GH abd: deltoid & supraspinatous
GH flex: coracobrachialis & clavicular fibers pec major
scap rotation: upper trapezius & serratus ant.
scap add: rhomboids & trapezius
scap abd: serratus & pec minor
What are the two most important bursae in the GH joint? What is their function?
subacromial and subdeltoid. to allow smooth gliding of the lower structures on the upper structures without the development of friction.
Look at Radiology of the Shoulder (probably not for quiz, but WILL BE ON TEST).
Did you look at the radiology? If not, give yourself a 1 or “red” and go study it right now. Work until you can honestly give yourself a 5 or “blue”.
At how many degrees of abduction does scapular movement become more pronounced?
how many degrees of forward flexion?
30° of abduction
60° of forward flexion
In elevation of the shoulder, which joint moves first, the AC or SC joint? At how many degrees does the the other one start moving?
SC, then at 100° the axis shifts to the AC joint.
What motions happen in the spinal column during the last stages of shoulder elevation?
thoracic: ext. and ipsilateral rotation
cervical: ipsilateral side bending (atlas & axis) and rotation (atlanto-occipital joint)
Main action of the rotator cuff muscles: supraspinatous: infraspinatous: teres minor: subscapularis: What are the 3 antagonists to these motions?
supraspinatous: prime mover of GH joint
infraspinatous: humeral head downward translation and humeral ext. rotation.
teres minor: humeral head downward translation and humeral ext. rotation.
subscapularis: humeral head downward translation
Antagonists: lat dorsi, pec major, triceps
