Hand axes were no doubt a multi-purpose tool. Research on their cutting edges has shown that, in many cases, they were used for butchering meat. This would include extracting bone marrow (which would explain the pointed end) and general hacking through bone, muscle and tendons. Experiments at Boxgrove quarry would appear to back this up. We know for sure that Neanderthals, at least, were hunters of large mammals such as mammoths, and that may be true of other hand axe cultures. The need for such a heavy tool is thus easily understood. Wielding a hand axe requires considerable strength, but Neanderthals were stronger than us in their upper bodies.