you're trying to learn the upper extremity nerves aka the nerves in the arm so let's go to arm you or arm university arm university is important and you should be able to name some of the nerve injuries that will classically be asked on USMLE and comlex so this is a mnemonic right here just by using the phrase arm you and name some we're going to correlate all of the upper extremity nerves to the corresponding injuries and these are going to go in order so let's start with the axillary nerve so the a in arm you and the end in you should be able to name some nerve injuries they go together so we're talking about an axillary nerve injury so the axillary nerve arrives from the c5 c6 distribution and the axillary nerve will get damaged if you have a surgical neck fracture so the a in arm u stands for axillary axillary nerve and the N in name some stands for the neck fracture or the surgical neck fracture so the first really high-yield bit of information is to know that if you have a surgical neck fracture of the humerus it will damage the axillary nerve and you can remember that because the first letter in our mu and the first letter in name some go together so a and n axillary and neck or surgical neck so we are at armed University and you should be able to name some of the upper extremity nerves and their injuries the first letters go together so axillary and neck so let's move on now we're going to talk about the next letter R and R will go with the A&M in name some so the R in arm University and the a and the M in name some upper extremity nerves so if you haven't already guessed R stands for radial nerve and radial nerve comes from c5 to t1 now a radial nerve injury can be due to either a problem at the axilla or a mid-shaft fracture of the humerus so if you put something up tightly against your armpit or your axilla you push on the radial nerve and can cause a radial nerve injury now this is sometimes referred to as a Saturday night palsy or a crutch palsy and the reason is is because the radial nerve runs right through the armpit if you push anything up against the armpit you compress the radial nerve and cause an injury so Saturday night palsy is the image on the left you get somebody who drinks a little too much they fall asleep on a chair I guess this happens on a Saturday night for some reason and the chair pushes up against the radial nerve in the axilla causing an injury of course for crutch palsy when you use crutches you bear all of the weight of the padded top part of the crutch into the axilla so crutches absolutely need to be padded at the top or they can cause radial nerve injuries so again we're talking about the radial nerve the R in arm University and a and M in name some the a for the axillary compression which happens in a Saturday night palsy or a crutch palsy and the M stands for mid-shaft fracture of the humerus so when that radial nerve comes out through the axilla it passes over the mid shaft of the humerus and you can get the injury there as well if you fracture the humerus at the mid shaft so that is the radial nerve injuries are in arm you a and M in name some a for axillary injury or axilla and M for mid-shaft fracture so we've done the axillary nerve and the radial nerve let's move on to the M in arm University so the M is the median nerve and that's going to correspond to the s in name some now we're skipping the e in name some that's why I made it lowercase it's just there to complete the mnemonic so median nerve goes with the s in name some arm the M in arm u goes with the s in name some so it's the median nerve comes from c5 to t1 and you injure the median the median nerve if you have a supracondylar fracture and I pointed the orange arrow to exactly where that would take place Supra meaning just above condyle our meaning the condyle our region so just above the condyle our region and condylar of course like epicondyle condylar so right above where the medial and lateral epicondyle are the supracondylar area is just above that on the humorous so if you fracture that area you're going to injure the median nerve because the median nerve runs right over that area so em in armed University and s in name some they go together so the median nerve is injured by the supracondylar fracture let's wrap up by talking about the ulnar nerve and U is for onar and it goes with om and E in name some so at armed University you should be able to name some upper extremity nerve injuries and om and E go together so we're just finishing the mnemonic now so the owner nerve comes from c8 to t1 and no stands for outstretched fall and M e stands for medial epicondyle our fracture so regarding the outstretched fall if you fall on an outstretched hand you can actually injure the hook of the hamate and the hamate is a bone in the hand and actually the ulnar nerve passes right over the hook of the hamate and if you fracture that bone you can really injure the ulnar nerve so the O in name some stands for outstretched fall the M and the e stands for the medial epicondyle our fracture now look at our picture here look where that top purple arrow is pointing right behind the medial epicondyle runs the ulnar nerve so if you fracture the medial epicondyle or you injure the medial epicondyle through one way or another another you can injure the onar nerve so in armed University the U stands for own R and that goes with om and E in you should be able to name some upper extremity nerves o for outstretched fall me4 medial epicondyle our fracture so that's how you pair the injuries of the nerves with where they're occurring in the upper extremity and to wrap up this video I think we can use the nerves which you see on this slide and correlate them to their clinical findings now the reason that this is important is because some test questions will go after either the clinical findings or they'll go after the location of the nerve injury or maybe the origin of the nerve itself so like if they're going for ulnar nerve the answer might be c8 - t1 but in any event you need to be able to correlate all of this information because they'll give you some information in the question and ask you for some output in the answer so if in the event they're asking for clinical findings or even giving you the clinical findings you need to be able to correlate them to the nerve injury so by using the letters that you see here in colors so a RM and you arm you using our mnemonic we can actually use those letters and correlate them to findings so in an axillary nerve injury a four axillary a and arm you you have problems with abduction of the shoulder so you cannot abduct the are two radial nerve in arm University causes wrist drops so incredibly important in high-yield to know that a radial nerve injury will clinically manifest as rest drop and I'm spelling wrist with an R instead of a W because it makes sense because we're talking about are four radial nerve so arm University the R in arm University stands for wrist drop a median nerve injury will cause what's called an ape hand and I use the M in median nerve to remind me that it causes monkey hands so M for monkey which reminds me of ape and and M for median nerve injury you can see in the picture what the ape and looks like it's like strict a deduction of the thumb trouble with opposition and a little bit of slanting of those fingers so look up what the actual wording is to describe what you see but that's a picture of the ape and and then the ulnar nerve injury is easy because they call it the owner claw the ulnar claw claw that's what you'll see in an owner injury arm University the you and arm you you for the ulnar claw but that's it guys I really hope that this is helpful it's a very high yield topic very annoying to learn but spending up just a little bit of time on this will get you a lot of free points on test day