Looking for an old video, might not be available any more though…

[littlebutts]

I recall watching a brief tv clip from Japan that was measuring the force that Hakuho and/or Kotoshogiku hit with on the tachiai. Age of the video is going to be contemporaneous with their careers I’m guessing… Thanks in advance!

[yohcun]

Sound's like NHK's sumopedia video on the tachiai. Vid linked to time.

 

[littlebutts]

Not quite but an interesting video nonetheless! I appreciate it. The video in mind may have vanished from YT since I saw it. I distinctly remember them measuring Hakuho’s tachiai and stating that it was roughly equivalent to falling out of a 3rd storey window onto concrete. Kotoshogiku was the other feature because of his signature tachiai. Maybe one day I will find it again and I can share with you all. 

[Gospodin]

13 hours ago, littlebutts said:

I distinctly remember them measuring Hakuho’s tachiai and stating that it was roughly equivalent to falling out of a 3rd storey window onto concrete.

Chances are you are dead when falling from ~7m onto concrete. Yes, Hak had his attidude, but he certainly wasn´t a serial killer . Seems to be a bit exaggerated by the video makers (if my math does not fail me, a 50 kg person would be exposed to a force of around 30 tons upon impact).

Edited August 5 by Gospodin
quick calculation and editorial correction

[Inside Sport Japan]

It's a Samurai Spirit episode with Nicolas Pettas

[littlebutts]

Thank you, that’s the one! I guess my memory is more or less correct in terms of the claims made re: force of impact. Much appreciated!

[Jakusotsu]

4 hours ago, littlebutts said:

I guess my memory is more or less correct in terms of the claims made re: force of impact.

Your memory might be correct, but it's still nonsense.

[Jakusotsu]

To elaborate a bit on the "falling out of a 3rd storey window onto concrete" analogy, because it's wrong on so many levels:

Translating the collision of two bodies into "force" doesn't make much sense when you want to describe the impact. Picking "concrete" here makes the analogy even more useless, because falling on a thick mattress would imply the same formula for "force", and I'm sure which kind of floor you'd prefer to land on.

What you're trying to do here is comparing an inelastic collision of two equally sized bodies with a collision of an soft human body with a rigid and rather immobile planet. Guess which part will take the brunt of that collision? That's not a case of apples and oranges but cranberries and pumpkins.

Hakuho may be the GOAT, but he's no celestial body yet.

Edited August 6 by Jakusotsu

[RabidJohn]

2 hours ago, Jakusotsu said:

... rather immobile planet.

On the whole I agree that the falling on to concrete analogy is crap, but the pedant in me would've preferred 'relatively immobile planet'...

I need no analogy to understand that Hakuho hit with the force of a 25-stone bloke who'd spent a lifetime practicing crashing into people from a 'standing' start.

[Jakusotsu]

On the other hand, wasn't Hakuho's tachiai praised for its absorbing power? I remember a video about that as well, but I don't know if it's the same as above (didn't watch).

[Gospodin]

Would fit his read-and-counter style

[Yamanashi]

8 hours ago, Jakusotsu said:

To elaborate a bit on the "falling out of a 3rd storey window onto concrete" analogy, because it's wrong on so many levels:

Translating the collision of two bodies into "force" doesn't make much sense when you want to describe the impact. Picking "concrete" here makes the analogy even more useless, because falling on a thick mattress would imply the same formula for "force", and I'm sure which kind of floor you'd prefer to land on.

What you're trying to do here is comparing an inelastic collision of two equally sized bodies with a collision of an soft human body with a rigid and rather immobile planet. Guess which part will take the brunt of that collision? That's not a case of apples and oranges but cranberries and pumpkins.

Hakuho may be the GOAT, but he's no celestial body yet.

I see this sort of analysis all the time, and it's a staple of auto safety studies.  If you watch a car hit a wall, the simplest assumption is: you measure the time for the car to stop, divide that into the initial speed (∆v/∆t) and multiply by the car's mass, hence F = ma = m(∆v/∆t).

In Hakuho's case, they watched the hip point (assumed to be the center of mass) and monitored the time elapsed until it came to instantaneous rest.  The rest is simple to calculate.

What assumptions they made about the 60 kg person I'm not sure, but in free fall it would travel at 14.7 m/s just before impact.  Assuming the 608 "kgW" (5960N) force, the body would stop in about 0.15 seconds

[RabidJohn]

In motor racing they now describe crashes in terms of g-force experienced, which is a measure of the deceleration caused by the crash. In F1 anything >25g results in the medical car being called out and the driver taken for observation, even if they say they're okay.

[Jakusotsu]

3 hours ago, Yamanashi said:

What assumptions they made about the 60 kg person I'm not sure, but in free fall it would travel at 14.7 m/s just before impact.

And how would that fit a typical sumo tachiai? Both numbers are way off.

[Gospodin]

It just doesn´t fit. As you wrote, the comparison in the doc simply doesn´t hold water. The time to come to rest (in any sense) is much shorter than 0.15s when falling on concrete, thus the force much higher.

 

Edited August 7 by Gospodin
clarity

[mugatake]

This same Professor Yuasa also later claimed that Hakuho's tachiai moved at the same speed as Usain Bolt's starting dash, if that rings a bell for anyone.

https://www.nikkei.com/article/DGXMZO84435650W5A310C1000000/

 

[Bunbukuchagama]

1 minute ago, mugatake said:

This same Professor Yuasa also later claimed that Hakuho's tachiai moved at the same speed as Usain Bolt's starting dash, if that rings a bell for anyone.

https://www.nikkei.com/article/DGXMZO84435650W5A310C1000000/

 

He could be an Olympic champion in 5-yard dash.