Neanderthals skeletons had some fundamental differences with ours.
Aside from their stockier build and cranial differences, Neanderthal bone density was twice that of Homo Sapian sapians. These beings were built like Mack trucks compared to us. I really wish that we could find a frozen Neanderthal in the Alps like the Ice Man mummie, surely there are at least a few preserved in such a manner.
Here's an excellent webpage on some current Neanderthal DNA research.
http://www.nature.com/nature/fow/000330.html