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thotcandy
ugh, I saw Ca2+ and stopped thinking.
+18
meja2
Lesson learnt: read the answer choices very carefully :( Automatically went for Ca2+
+
chaosawaits
I guess you could call that a Cattrap. I'll see myself out.
+1
mousie
I was thinking along the lines of overhead motion - damage to the subacromial bursa which is between the acromion and the supraspinatus ... also its the most commonly injured rotator cuff m. so could have guessed this one right
+2
sympathetikey
Thanks for the explanation. I was scratching my head as to why this is correct, since supraspinatus only does 15 degrees of abduction, but you make a lot of sense.
+1
ls3076
why would injury to supraspinatus cause weakness with internal rotation though?
+9
maddy1994
ya the whole question pointed to supraspinatus ...but last line internal rotation made me pick subscapularis
+3
darthskywalker306
I went for Trapezius. That shoulder flexion thing was a big distraction. Silly me.
+1
hookofhamate
for those who got confused w/ internal rotation - im pretty sure what the last line (pain and weakness with abduction, esp with internal rotation) is describing is the empty can test, which is basically only for supraspinatus injuries because that motion of your arm traps the supraspinatus tendon against the humerus head and causes pain (someone correct me if im wrong pls) but yea, i only figured it out because i had to do the motion with my arm
+
zasachwa
Basically, "internal rotation of the arm decreases the effect of the deltoid muscle on abduction and allows isolated examination of the supraspinatus muscle"
+
Person has Lambert-Eaton syndrome (hx of lung cancer, and muscle activity that is better with use.
Presynaptic Ca2+ antibodies prevent the release of AcH presynaptically because the antibodies prevent the depolarization within the cell and prevents synaptic vessels of ACh from leaving.