- Do the preparation activity to help you with words from the video.
- Watch the video then play the games to check your understanding.
- You can also print the worksheets for more practice.
- Remember to read our discussion question and leave a comment!
Xand, you're hopeless at this!
Look, I may not be very good at this, but I've got a trick for you that will make even the best catcher find it very hard to hold the ball.
It's Doctor Xand's world-famous 'How to stop your hand working' trick.
Now, what this trick does is prevent one of your hands from working. Does anyone have any idea how we might do a trick like that?
If you put your hand up like that, like, so the blood goes down.
Ah, I like this. So if you have your hand up long enough, the blood supply isn't quite as good and it might go a bit numb and tingly.
Nice idea. But who wants to see a trick that will stop you being able to move your fingers?
OK, great. Chris, stick your thumb out like that and then use this hand. Wrap it around your thumb. And then I want you to squeeze your thumb as hard as you can and count to sixty. OK? Are you ready? Go!
One, two, three, four … fifty-nine, sixty.
Now relax that hand and very slowly and gently pull your thumb out. And now what I want you to do as slowly as possible is open the fingers on that hand.
They've got stuck and I can't move them and I am trying to do it very slowly.
Now try and do it quickly. Flick your hand open. There you go, and your hand's working again. All right, who wants to have a go at that?
Go. One, two, three, four, five ... fifty-eight, keep trying, fifty-nine, sixty. Now very slowly get that thumb out. OK? So who's stuck?
Are you really stuck?
OK, open your hand quick. So in three, two, one, open your hand. Ha, ha, ha, ha.
Willow, tell us what happened and why do you think it happened?
I felt a bit like a cramp, but, like, not as bad.
And I think it happened because we'd been squeezing it so hard for so long.
When you hold your hand in that position for a long time at a very high pressure it squeezes some of the fluid away from around the tendon and so the tendons get a bit stickier and find it harder to pull your fingers straight, and soon as you shake it out the fluid can flow back and it all starts working again properly.
Who thought that was a good trick?
Try the trick! How does your hand feel? Do you know any other body tricks? Tell us about them!