Shoulder Pathophysiology Flashcards
why is the shoulder so prone to instability?
bc of the amount of mobility at the jt with mostly ligamentous/muscular restrictions and not a lot of bony stability
how much space should be in the subacromial (SA) space?
4-11 mm
what are the anatomic variants that can cause impingement at the shoulder?
type 1 (straight) acromion
type 2 (curved) acromion
type 3 (hooked) acromion
what is the most problematic acromion type?
type 3
what is the least problematic acromion type?
type 1
what things can contribute to shoulder impingement?
decreased SA space
anatomic variants
shoulder girdle kinematics
RC pathology
degenerative changes
overuse
the critical zone largely involves what two structures?
subacromial bursa
supraspinatus tendon
tendinitis in the shoulder primarily effects what 2 tendons?
supraspinatus tendon
long head of the biceps (LHB) tendon
how can RC weakness/fatigue contribute to tendinitis?
bc it causes the humeral head to rise higher and irritate the tendons
how can posterior capsule tightness contribute to tendinitis?
bc it causes the humeral head to rise superiorly and irritate the tendons
mobility impairments in what jts may cause tendinitis in the shoulder?
GH, SC, ST, AC
what things may contribute to tendinitis?
RC weakness/fatigue
capsular restrictions
anatomic variations
mobility impairments
those with tendinitis may develop what?
calcific tendinopathy or rupture
what % of those with tendinitis develop calcific tendinitis?
3-7%
are males or females more likely to develop calcific tendinitis?
females
what age group is more likely to develop calcific tendinitis?
those over 40 y/o
how can we differentiate tendinitis?
resistance testing and palpation
how is bursitis different from tendinitis, fx, arthritis, or dislocation?
there is pain with movt, no pain with resistance (or very minimal pain), and (+) impingement signs
bursitis causes pain with passive motion in what directions?
abduction
IR
horizontal adduction
where would someone with shoulder bursitis be tender?
subacromially at the greater tuberosity with the arm in extension
what are the special tests for impingement?
Hawkins Kennedy
Neer
how do we perform the HK test?
in sitting, flex, IR, add the arm and push up on their elbow
what is a positive HK test?
pain in the shoulder
how do we perform the Neer test?
in sitting, flex, IR the arm over the head and stabilize the scap