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[RC] how hard do you hit the ground? - k s swigartEd said: it will enable you to calculate how hard you hit the ground when you horse bucks you off, or dumps you with the BIG SPOOK. i took it one step further and tried to figure impact in pounds per square inch, depending on which body part you land on. The problem with either of these calculations is that, while they tell you how fast you were going when you"hit the ground" they don't actually tell you how hard. To make the conversion from how fast you are going to how "hard" you hit (in pounds or psi) you need to have the underlying assumption that all of your body weight stops instantaneously when you hit the ground. Nobody does. So when Laura Hayes asks: but now I want to know WHY IS IT *HARDER* THAN WHEN I WAS 20??? It is because (assuming you haven't gained weight since then:)) you are less good at decelerating AS you hit the ground than you were when you were 20. The faster you "screech to a halt" when you meet the ground the harder you hit it (i.e. the more pounds or psi you have). Incidentally, it is much easier to decelerate as you hit the ground (rather than screeching to a halt) the more forward momentum you have when you meet the ground. It helps even more if the ground is sloping away from you. Neither of these things is taken into consideration in the calculations made in the article. The article, in fact, only provides half of the equation with respect to how hard you hit the ground. However, since it is the easy half of the equation to calculate, it is understandable why this is all that is done....just don't be fooled into thinking that it tells you how hard you hit the ground, it doesn't even come close. The variables associated with the deceleration part of the equation are substantial. The difference between landing on your feet and decelerating slowly by absorbing the impact with your knees is COMPLETELY different from hitting the ground with and extended hand and locked elbow, because then the only absorbtion of the impact comes in when the bones of your arm and/or wrist break (depending on the angle), however, this also slows your rate of deceleration in a completely different way. :) kat Orange County, Calif. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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