Quote:
Joep Schuurkes wrote:
I don't think more impulse is delivered there. The initial point of contact will take the most impact: it needs to absorb the force from falling
|
Hm, I've thought about it and I still think the vertical impulse is distributed across the roll rather than localized to the initial point of contact. (it's a glancing contact) For instance those parkour guys off the roof-- there is no way their vertical momentum is being handled mainly by the initial point of contact (that would be a "hit" followed by a roll, rather than a nice smooth roll, right?).
I think the roll turns some of the downward momentum into horizontal momentum, doesn't that sound right? in other words it does a lot of work, pushing on the ground in order to create some new horizontal motion out of the force of the downward "would-be-splat."
Well, if that is right, it would mean the line of the point of contact really does take a crunch. In which case, I still wonder why it is ok to have the lower back take so much of that. If it's not correct-- well, then I guess it is clear.
--JW