5 ms·
I guess this is just a silly little thought experiment, but the final estimate (6.97s 100m) is quite ridiculous on its face. The heavy lifting seems to be done
by b450 2y ago
I guess this is just a silly little thought experiment, but the final estimate (6.97s 100m) is quite ridiculous on its face.
The heavy lifting seems to be done by the study linked in the "anatomical studies suggest peak speeds up to 15.6-17.9 m/s (35-40 mph) are achievable" line. I'm not sure where those exact numbers were pulled from - I can't find them with a cmd+f. One line in the study uses some nearby numbers:
> If, for simplicity, we assume no change in contact lengths or the minimum aerial times needed to reposition the swing limbs at top speed, the average and greatest individual top speed hopping forces (Favg) of 2.71 and 3.35 Wb would allow top running speeds of 14.0 and 19.3 m/s and of 50 and 69 km/h, respectively
But the study concludes that, even though our leg extensor muscles can produce much higher maximum forces than those generated during sprinting, the "contact length" imposes a constraint on these "hopping forces":
> Because humans have limbs of moderate length and cannot gallop, they lack similar options for prolonging periods of foot-ground force application to attain faster sprinting speeds at existing contact time minimums. Consequently, human running speeds in excess of 50 km/h are likely to be limited to the realms of science fiction and, not inconceivably, gene doping.
So the craziness of the original estimate seems to follow from on a misreading of that study.
- buildbot 2y agoHumans can’t gallop? https://www.discovermagazine.com/planet-earth/why-humans-prefer-not-to-gallop https://www.discovermagazine.com/planet-earth/why-humans-pre... https://journals.biologists.com/jeb/article/216/7/1338/12063/Biomechanics-of-human-bipedal-gallop-asymmetry https://journals.biologists.com/jeb/article/216/7/1338/12063...
- jamiek88 2y agoWe don’t do it efficiently or effectively would be better than saying we cannot do it. It’s only useful for going downhill quickly which we’ve all subconsciously or perhaps even mindfully done. From your link: > Gallopers exerted that effort unevenly, with the front leg doing more work than the back leg. And the galloping stride, researchers saw, demanded more from the hips than running did. This tired people out quickly. Out of 12 treadmill gallopers in the study, 4 gave up before the end of their 4-minute session, complaining of fatigue and stress in their hips and thighs. (An intended 13th galloper couldn't figure out how to gallop on the treadmill belt in the first place.) When researchers calculated their subjects' metabolic rates, they found that galloping was about 24% more costly than running at the same speed. In other words, galloping burns up more energy, takes more effort, and is less comfortable than running. It's no wonder we don't usually opt for it
- buildbot 2y ago> Because humans have limbs of moderate length and cannot gallop Yes, we don't because it's not great, but that's not the same as not being able to. (This is very pedantic sorry, it's just a stronger claim than it needs to be which bothers me). Also, I wonder if that changes if you have very uneven leg lengths?
- ohyes 2y agoI mean, this is a bipedal gallop, standing upright. What if someone were to train for running on both their hands and feet, the way a horse, dog, or cheetah does? I’ve seen a video of a young woman doing this, and it looked very uncomfortable/unnatural and it was frankly terrifying to imagine a human running at you in this way. Mechanically it seems like the advantage would be using more muscles and being able to take advantage of your core and upper body when pushing off in addition to the legs. landing seems like it would be a challenge as fingers aren’t really made for that.
- signalToNose 2y agoSkipping world championship when?
- tetris11 2y agoI've genuinely wondered whether humans could "run" faster if they employed full body flex and did a sort of springing cartwheel, using all the muscles in their body to propel them forward. Imagine a slinky, but more elastic and with better roll.
- ljlolel 2y agoIn 2048, the fastest human on the planet will be a quadrupedal galloping man https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4928019/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4928019/
- rurban 2y agoAlso https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2016.00056/full https://www.frontiersin.org/journals/bioengineering-and-biot...
- pfortuny 2y ago“The winning time was fitted to a rational fraction curve for the quadruped records (r2 = 0.823, adjusted r2 = 0.787, F = 26.9, P < 0.05) and to a linear curve for the biped records (r2 = 0.952, adjusted r2 = 0.949, F = 336.1, P < 0.05; Figure Figure1).1).” Unfortunately, a linear extrapolation implies that at some time, the bipedal 100m will take negative time…