which part of the impact do you think is whiplash, the first contact when I landed on my hand or the second when I slid onto my butt?

Do you think this is enough force to cause a whiplash if I was able to catch myself with my arm? Or could the force have extended to my neck?

Since the hill was downward sloping I did not need to fall as far back before reaching the ground compared to if I fell on a level surface for example. Does this make a difference?