engineers and mathematics

These are skills I lack. But I have a question. Would it be possible to figure the (force) ones melon takes at impact when face planted on landing toe edge W2W in sea water? I have done this a couple times and well darn it hurts bad, chest, arms and especially my poor head.

The info I can provide is the head in question is 5'-10" at the top edge above the pivot.

The initial travel speed is 23 MPH.

Acceleration is developed from a 70' rope.

If arc is useful than figure maybe 4 feet at the apex.

I have no idea what a head weighs, or how to figure acceleration off the rope length or how to figure force once those numbers are achieved.

I tried last night, dug out the books... put the books away and Goggled. Tore up some paper and my head hurt worse than it did from impact.

I'm just curious because I seem to have a nasty habit of catching that lead edge on landing and things start to happen fast. real fast. Painfully fast.

If you have the school and skills I would be obliged.
Not quite P.U.I. only two beers in.