All of these video are awesome 6 and 7 seem to be repeats of one another and show you the arm in two different ways... kinda. Solid stuff here, they do make some mistakes, but thankfully the group seems to be really on top of it and catches their mistakes.
All Lecture in the .amr format can be played with quicktime, which comes standard with iTunes or your can just download it for free I believe. The basic free version should do the trick if you guys were having trouble with it.