3.3.5a HuM glitch

[Cleavelands]

Hello everyone, i have found a glitch on 3.3.5a (only on Human Male models) where your right elbow "sinks" into the arm once you mount up, run with speed buff or stay still underwater. Its almost like someone chopped a piece off. I have been trying to solve this for like 4+ days now and still wasnt able to come to an solution. I came across this page randomly and since i see that you guys are Pro at what you do i have decided to seek some help here.

Screen of the glitch : Imgur: The most awesome images on the Internet
The left arm looks normal : Imgur: The most awesome images on the Internet

I have tried to download various clients from ENGB to ENUS versions and the glitch is still there.
(this is only happening on wotlk clients)

Is this something that can be fixed by downloading an proper uncorrupted client? if so, id be eternally grateful if someone provided an working DL link for such client.

Or is this something that exists in all the 3.3.5a clients out there and can be fixed by switching HuM model for lets say Cata, MoP model? this is my first time trying to solve such issue, i am not experienced in this kind of stuff and i literally dont know what im doing.

Could someone make an strict guide about how to fix this? it would help me alot and your time would be much much appreciated.

Many thanks and have a good day.

Edit : Id like to correct this with classic models, not the new ones