The Arm Spin That Stops a Fall

00:26 that phone sinking in the background😭😭🤣

Not the phone floating in the pool behind him 😭😭

Props to Steve Mould for stopping time to give us a cool intro!

Love the joy on the face on the person pushing Steve. Science is FUN!

The pure joy in her face, as she's pushing you over!

well it didnt stop you from falling in the water now did it

10:00
When I learned how to wind surf, I had to overcome the "I'm getting pulled forwards, I should bend forward"-urge and do what actually helped: leaning backwards.
So that's where I think I have witnessed the fast and slow brain stuff 👍

3:02 “you might call your pivot point ‘feet’ “ , this is the kind of real-world grounding so many high school physics teachers fail to include in their lessons. It’s also omitted by university-level physics professors, who demand you simply use the superior term. 😂

There is another reason why humans don't perpetually spin their arms after a recovery. Our feet have a considerable length of contact with the surface of the floor, which was missing in your stick man sim. This extra length means your feet can apply a downward normal force near the tip of the shoes' toes to provide a countertorque from the ground [tau = r x F]. This also explains why the arm spinning is needed mostly when you are pushed backwards and not when you are pushed lightly forwards

10:15 Missed another cool step here, deep tendon reflexes completely bypass your brain and make instant corrections faster than the signal can even go up your spine to your brain and back. That's the same reflexes that get tested when a doctor taps your knee or similar, that reflex is there because it's responding to that tendon stretching by instantly working to shorten it again, and there's slightly more complex reflexes that involve cross wiring between these pathways to contract some muscle groups and relax others, all entirely within the spinal cord. Your brain has to play catch-up with these as well as the fast responses it has itself.

Could have worn flip flops to get pushed into the pool but chose full sneakers. You're a man fully committed to the game

I've never once called my pivot-points "feet" thank you very much.

I'm a gymnastics coach and have been teaching my students this for years. A secondary way our instincts use conservation of angular momentum is shortly after a push/fall when your brain has determined that windmilling your arms (and other counter measures) is not enough to stop your fall. It then pulls your legs in the same direction of rotation as the fall, pulling your upper body slightly in the opposite direction, making it so you land in a slight pike position roughly on your butt rather than a straight line where your head can smack into the ground (see your body position at 4:59). Its the opposite effect of doing sit ups and needing something to hold your feet down because they want to come up.

Is that really angular momentum? It looks like a push pool action to me.

The editor had a lot of fun on this one!

There is a noticeable increase in quality in the video! Info and script is great as always, but props on the filming and editing!

props to him for being pushed in the pool so many times just to teach us

I remember watching a ski jumper in the winter olympics lose control and start flailing his arms. The commentator said, “He’s rolling up the windows!”

Spinning my arms helps me grab the person pushing me in. As to pull them in with me.

No robots were hacked in the making of this video.

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