I'd agree with the d6 per 10' similar to falling damage. I suppose you could give them their strength modifier if they really want to throw themselves into it.
a club does 1d6 + str
falling does 1d6 / 10'
Per my akido master friend, you can not move your body faster than gravity (and thus he taught how to move out of the way by falling to where you want to be).
Therefore, using these 3 principles, it seems that one can probably not run faster at a wall than you can fall. Therefore, you cannot really take more damage than what you would take from a fall.
Note, that running cannot increase your speed per 10', unlike falling, therefore, you can't take 2d6 by running 20'