One of the things I find myself doing during the parkour classes that we teach is explaining physics to our kids and why it’s important. In parkour, it all comes down to physics, and the more you understand it, the better you’ll be able to figure out the moves and the more confident you’ll be it what you’re doing. Newton’s three laws of motion form the basis of classical mechanics and, according to en.wikipedia.org, can be summarized as follows:
These are reoccurring themes in parkour moves. One of the common explanations during our classes is in regard to jumping and the third law, which can also be stated as “For every action there is an equal and opposite reaction.” When we jump, we push down on the earth (or down and back, if we are jumping forwards) by extending our ankles, knees, hips and also shoulders. That’s why we swing our arms in time with opening our hips, because by swinging our arms up, we are exerting a greater push down on the earth, and since the earth doesn’t move much (but in theory, it actually would move a teeny-tiny bit) the result is that we get air-time. It’s an interesting experiment to try to “jump” by just swinging your arms without using your ankles, knees, or hips. You can actually get a bit off the ground, and it’s magnified when you do it in time to the rest of your jump. One of the common mechanical breaks that parkour coaches notice in new aspiring traceurs is the lack of optimal use of the arms in time with their jump. This also commonly happens with CrossFitters doing box jumps who don’t have a particularly strong athletic background.
At The Cave we have commonly had kids do their school projects on parkour and take video footage during their parkour classes. I don’t know if any of them have done physics presentation for their projects, but the material lends itself extremely well. During the next couple of months I intend to intermittently post several parkour physics projects that young traceurs from around the country or even overseas have put together, after all, the more you understand, the better you can get!
Here’s the first one:
Are there any errors or inaccuracies in our young parkour and physics teacher’s explanation? Can anyone identify them or make any clarifications? All around, I think it’s a great video.