I found this video by chance and it's pretty interesting.
https://youtu.be/tHMM67xEul4I've seen these large, leaf-shaped spears before but I had never realised that they had a spike on the other end. In throwing the spear, it seems that they use the thin spike.
Ok, so what? Well, I think this style of spear is a work of absolute genius. Having the broad leaf blade would be good for hand to hand, you're able to cut and thrust with it, but for throwing, the wide blade wouldn't get much penetration, hence thin spike (of course, it's a very sharp edge so would do considerable damage but wouldn't penetrate as far as the spike). Here's something I noticed though. Having both options (wide for hand to hand, thin for throwing) is really advantageous, but they also compliment each other. Having the spike, gives the spear a counter balance to make it more lively in the hand to allow you to more quickly and easily make cuts and thrusts, and the wide leaf blade works like flight feathers to stabalise the spear in flight. Genius! Obviously, these spears have been used for countless generations and so are highly refined weapons, but I never realised just how clever a design they are and thought I should share here.
It's mentioned that the thin spike isn't used for hunting and just for sticking in the ground, but then it has, in all of the footage of them throwing, using the spike. This is somewhat confusing because of the advantages listed above and how effective it obviously is this way round, but perhaps there are other reasons not mentioned. Any ideas? Personally I would want to use it as described, a combination weapon that actually works.