Topic: 10-15 foot Drops....

[Shawn Meilicke]

if it wasnt so horrible it would be hilarious...

[Hayden Williams]

So, this is a little late, but I feel it would be extremely helpful in the case of understanding our abilities., and it's a little shift away from all useless, Yeah I jump off 15 feet all the time, and my grandma sometimes joins in too, were so bad, comments (whos face is that?)

First of all, can someone put a formula that shows the force of impact, with fill in the blanks for height/weight

Secondly, lets say the force is 300 lbs., I myself can lift 300lbs. with relative ease, does that mean it's SAFE to put that sudden shock on the body, because doing the leg press it's more of a gradual increase in force

Thirdly, If theres any physics einsteins this is for you, what about doing Cat leaps, I would think they create a good deal of stress on the legs as well, If I had to guess( I've never measured) I'd say I can clear around a 10-11 ft Cat with no pain whatsoever, but is there any permenant damage (feel free to ignore I doubt anyone knows)

[Charles Moreland]

So, this is a little late, but I feel it would be extremely helpful in the case of understanding our abilities., and it's a little shift away from all useless, Yeah I jump off 15 feet all the time, and my grandma sometimes joins in too, were so bad, comments (whos face is that?)

First of all, can someone put a formula that shows the force of impact, with fill in the blanks for height/weight

Secondly, lets say the force is 300 lbs., I myself can lift 300lbs. with relative ease, does that mean it's SAFE to put that sudden shock on the body, because doing the leg press it's more of a gradual increase in force

Thirdly, If theres any physics einsteins this is for you, what about doing Cat leaps, I would think they create a good deal of stress on the legs as well, If I had to guess( I've never measured) I'd say I can clear around a 10-11 ft Cat with no pain whatsoever, but is there any permenant damage (feel free to ignore I doubt anyone knows)

No we cannot give a formula because there are too many variables.

Leg press is not a good gauge. I can leg press over 800#s and can barely knock out 5 reps of 285# squats. Take extreme caution when messing around with plyometrics (this includes the plyometrics of parkour) because the damage they can do is not acute and is often overshadowed by fun, adrenaline, endorphins, whatever.

[Hayden Williams]

Leg press is not a good gauge. I can leg press over 800#s and can barely knock out 5 reps of 285# squats. Take extreme caution when messing around with plyometrics (this includes the plyometrics of parkour) because the damage they can do is not acute and is often overshadowed by fun, adrenaline, endorphins, whatever.

I see,Don't worry i have no intention of messin' around, I just used the leg press as a example to clarify what I was saying, I have no intentions of taking drops at exaggerated heights, and other shenanigans. Basically that post was just an attempt to understand my capabilities. Do you reccomend I look into plyometrics? If so, where?Or do you think Its just impossibly complicated and I should never look into it

[Brett Robert]

Thirdly, If theres any physics einsteins this is for you, what about doing Cat leaps, I would think they create a good deal of stress on the legs as well, If I had to guess( I've never measured) I'd say I can clear around a 10-11 ft Cat with no pain whatsoever, but is there any permenant damage (feel free to ignore I doubt anyone knows)

You might enjoy this article Hayden. It's from Popular Science, they analyze Levi's rolls.  I haven't read it in awhile, so I can't remember exactly what it says.  Just remember, Levi is an incredibly gifted athlete and an advanced practitioner.  What's safe for him is different from what's safe for you or I.

[Hazim Salem]

Thirdly, If theres any physics einsteins this is for you, what about doing Cat leaps, I would think they create a good deal of stress on the legs as well, If I had to guess( I've never measured) I'd say I can clear around a 10-11 ft Cat with no pain whatsoever, but is there any permenant damage (feel free to ignore I doubt anyone knows)

Okay, i'm not physics einstein, but cat leaps are different because gravity doesn't pull you towards the wall. There's no permanent pushing on your legs while doing a cat leap. When falling from above, gravity keeps pulling until the end. That's one difference, and i dont know about the rest

[Jeremy Osborn]

Objects fall at 32.2 feet per second (9.8m)
So.. im 6 foot.. weight 160lbs.. and im going to drop 15 feet.. it will take about a half a second at maximum velocity to hit the surface.. and lets say the surface is concrete... 160lbs going in a downward motion with a velocity of 32 feet per second.. ouch....
Just some general stuff i guess.. am i on the right track? Im no physics major, actually only a 9th grader.. but i feel like that gives a general idea of the damage done....

[Hazim Salem]

Actually Jeremy, that's the acceleration rate. For every second of falling, 9.8 m/s adds up to your velocity. However, according to my calculations, you're close enough.
The thing about rolling is it extends your impact time. More time = less acceleration = less force. I know a lot of guys know this already but it's just for jeremy you have to take time into account. I read in some science website that Levi's roll from 10 feet high turns 12,000 lbs to only 460 lbs. :O

[Jeremy Osborn]

Lol i knew THAT 

[Hayden Williams]

Thanks Beretta.. By the way dude, everytime I saw you post I laughed at that face( i assume it was yours) that was your picture, whyd you change it man?

Thats amazing, 12000 to 460, Youd think a roll would take longer than .04 seconds though

[Hazim Salem]

.04 or .4?
if u have a stop watch, try starting and stopping as fast as u can. my fasted was .09
i think it's .4, which almost half a second. reasonable.

now i want to read that article again.

[Parkourzack]

Well, this jump seems pretty easy. I think you should keep on jumping from that height because it will help in the long run. I've been Freerunning for a little longer than 2 years now, and I do jumps right around 15+ feet, and I'm fine. I have never broke a bone from doing that.

[Hazim Salem]

Well, this jump seems pretty easy. I think you should keep on jumping from that height because it will help in the long run. I've been Freerunning for a little longer than 2 years now, and I do jumps right around 15+ feet, and I'm fine. I have never broke a bone from doing that.

Are you sure it's 15+ feet? I have a friend of mine who says he's been rolling out of jumping 20 feet. Turned out his measurements are way off.
The issue about this is not broken bones; it's about damaging your knees on the long run, as in having crappy legs at age of 30. Drilling these jumps is good for getting used to them, but not conditioning your knees. Look out, bro.

[Jeremy Osborn]

Beat me to it Hazim 

[Rowe]

Here are a few loose and simplified calculations for your enjoyment, based off a 165 lb individual.
m=meter, s=second, J=Joules

At 1m, individual reaches a velocity of 4.43 m/s.
At 2m, individual reaches a velocity of 6.26 m/s.
At 3m, individual reaches a velocity of 7.67 m/s.
At 5m, individual reaches a velocity of 9.9 m/s.

Velocity builds as distance increases, as does the force of impact, measured in Joules.

1m = 735J, or 136 lbs-force/square-foot (like standing with your kid brother on your back).
2m = 1470J, or 273 lbs
3m = 2205J, or 410 lbs

There are a few ways we can think about this:
A) The higher you drop from, the more force you will have to dissipate with your legs and a roll.
B) Higher drops equal faster landing velocities, meaning less time to perform landing maneuvers.
A+B=C) The decrease in reaction-time and higher forces results in a near-exponential increase in difficulty. Imagine squatting 100 lbs in a half-second. Not too bad. What about 400 lbs in a quarter-second? Perhaps, but only with proper training and coordination.

[Jeremy Osborn]

WOW! Thanks Rowe!

[Hayden Williams]

Thanks man that's helpful. I love you. I assume a 110 pound individual, dropping from around 2m would be around 220-230? ( a complete guess) I would say I rarely go higher than 6 feet so thats super!

[Shawn Meilicke]

Thanks man that's helpful. I love you. I assume a 110 pound individual, dropping from around 2m would be around 220-230? ( a complete guess) I would say I rarely go higher than 6 feet so thats super!

per square foot

and im quite sure you arent one square foot (though im TOTALLY picturing a cube-midget now )

[Hayden Williams]

when I say super I'm being sarcastic, I just don;t feel the sarcasm icon..

Anyway I found a perfect picture of a cube midget!! i just can't upload it!!

[Shawn Meilicke]

link ittttt