okay um now I want to talk about hand pathologies um I can never cover all the hand pathologies um I um select a few here just um to give you an overview about how nerve injury how muscle tendon injury or how bone uh fracture in at the at the wrist of hand okay so uh if you recall uh the medium nerve Innovation uh in in the hand uh for the sensation part um is uh innovated the first three digit and half of the ring fingers um and for the motor it kind of innovate most uh most uh extrinsic muscles and four uh intrinsic muscles which are called loaf um the first and second uh Lum Co opponent's polies uh abductor policis breakfast uh flexor pois bra so here if you have a client who has a medium nerve py or injury you can kind of see that the low uh muscle is not working so this person will have difficulty uh bring uh the thumb away so because the abductor and flexors are not working and opponent is not working so this person thumb is really um not um functioning so what's still functioning is the adductor polies so that means this adductor Poes will bring the thumb toward other digit rather than away from the body because um the muscles uh that's in charge to bring the thumb away is not functioning so often times people will refer uh the medium nerve py to AP hand because uh it looks like the AP hand that the thumb is in know close to uh the four digit so really it's really um the individual has limited or no ability of the thumb to for opposition or abduction okay so um the AL nerve is is is quite different uh from the uh Med nerve so on the nerve innovates most the uh intrinsic muscles uh only the flexor car onys and have of uh the flexor digitorum profundus uh from the extrinsic muscle group are innovated by the own nerve so mostly the own nerve can innovate the intrinsic muscles the hypoth muscles uh uh the Lum Co the half of the lumos and all of the inas okay and sensation uh it innovates the last two digits of the hand so you can imagine when a person have that on the nerve py so what would that be um this person um lose the control uh of the um the fourth and the fifth um lumos and all the inas okay you can kind of see that the first too int is kind of atrophy right here and then um um because uh the first and the second lumus is inovated by the medium nerve so the index finger and middle fingers may look okay um but you can see that um the int is kind of kind of atrophy like this so uh if you recall to the extensor Hood mechanism that uh the because the intrinsic muscles lose lose um the function so it cannot counter uh the force that caused by the flex of tendon so uh but the extens tens are okay right and then the flex tendons are okay so that typically um when a person have that on ner poy the ncps U um will be in extension or hyper extension because the ex extensor tendon are working but because the intrinsic muscle are not working then the flexor tension are kind of bring the finger in then the PIP and dip are in Flex uh position and we have a name call claw hand like you know the hand kind of form as a claw okay okay so um that's the AL nerve py um here here okay so um you you need to you need to be careful because uh when we refer aler py yeah people people typically think about oh claw hand and that's um Inus and lose but uh the first and the second lose are okay okay so and what we see here is typically the mcps in hyperextension and IP inflection okay so these are the motor and think about the sensation so uh the fourth and the fifth digit lose the sensory from the innovation of the the on the nerve so this person may have difficulty U doing power grip may have okay but can this person lose ability to uh for position a little bit because all the inis is not working so uh this may feel like awkward but the thumb is okay so this person can still functioning but not like you know previously before the injury okay so these are the medium nerve and on nerve py and then the radio ner py is uh it's on its own so what uh what I need you to um pay attention is here the posterior intus nerve okay so um when it's at the upper arm it's called radial nerve and when it pass the superator or when it pass the um elbow joint it changed the name uh the radial nerve change the name to posterior interus nerve because it has um two branches okay okay so um so you may hear people um talk about regular nerve policy and it's related to drop hand but you may also hear people talk about pin syndrome which is posterior um Inus nerve so that's pin Syndrome again you when you hear that pin syndrome um you should know that um this is related to rer nerve so what happened when um the nerve G pulsy again the sensation is on the dorsal side of the hand so we know that um the person may have difficulty uh feeling on the dorsal side the hand but the V side should be okay so they still they can still manipulate object is the motor that can of um U make the hand function so hard you see here uh this is one of my my uh client so you see his extensors are all atrophy because you see here I asked him to extend rever it doesn't look like it's doing any extension and then I asked him to to make a fist this is the far farest um fist that you know the best fist that he can make which is really not a fist okay so what that means is um the extensors are not working but the flexors are okay but again because the flexors lose the counter um force or the stretch by the extensors the the hand cannot make a good Fist and the Hand cannot make a good grasp so what we typically do is make a U wrist uh splint which you um you will uh eventually make um a wrist splint to support the wrist into the functional position which is in slightly extension so that um the wrist uh can be stabilized to allow the Fingers um to function okay so these are the nerve injuries