If I position my feet and legs just right with my heel off the ground, and the front of my foot squarely on the ground, and get my leg started in a vibrating motion. It will continue to vibrate indefinately without any consious effort on my part until I “will” it to stop.
My question: Is that normal? Can everyone here spaz out there leg? Assuming someone can, I can do both at the same time, how about you?
Sorry, I know it’s completely irrelevant, but as a card-carrying member of the grammar police, I can’t help but to slap myself.
“Can everyone here spaz out THEIR leg?”
In response to the OP…
No…you’re wierd…'nuff said?
Seriously, I’ve never heard that this was a normal thing. However, it doesn’t sound like a worrysome thing either. Just enjoy your uniqueness!
I get this a lot, and its even more marked if you rest your foot on a bar of some sort (a rod, not a place to put drinks on), such that the bar goes accross somewhere behind the widest part of the foot IIRC). At some point, your foot will start to vibrate and can get quite violent until you take the pressure off.
THis happens to me…not all the time, but not infrequently - often associated with a period of stress or fatigue
Hmmm… what I’m talking about is completely innocuous and I do it for fun. If yours is stress related, you might want to check into that!
I also think that maybe Ruby hit this particular nail right on the head!
Aye, Captain, just set and raise the heel until my foot is resting on the ball and let er go, can drive the so nuts doing it.
“Sewing Machine Leg” is a term we use when rock climbing. When your leg is bent at the knee and your foot is positioned so that some or all of your weight is on the ball of your foot.
In the case of climbing, it’s associated with muscle fatigue – if you leg is fully extended, there’s usually no problem, or when you knee is fully bent, there is usually no problem. But that halfway point… as soon as your leg gets even a little tired, it shakes.
If the fatigue isn’t severe, you can sometimes “concentrate” to make it stop. If the muscles have been working hard, you’ll have to change positions to get it to stop.
This happens to me often. I’m sure it happens to alot of people, just some don’t notice it.
I sure did picture Robert Klein with a harmonica, singing, “I Can’t Stop My Leg!”
Can I join in to point out that should properly be, “Can everyone here spaz out his or her leg?” You know, if you want to get picky.
Yes, that happens to me, too. Sometimes it will even happen while stretching in exercise class, if my foot ends up in the right (wrong?) position. I’ve always thought it was the same response that you get from a dog when you scratch it in the right place.
Maybe it’s because I’m a gun-hording, yee-hawing conservative, but I’ve never bought into the whole “his or her” thing.
It’s all good, though.
A Straight Dope Staff Report on Why do your legs tremble uncontrollably sometimes when rock climbing?
Okay, we can just go with “his.” Grammar before feminism, every time. 
I don’t think what I experience is this “Sewing machine leg” that Eats_Crayons and the link is talking about because there is certainly no fatigue or stress involved; it’s like herman_and_bill said: just put pressure on the ball of your foot and let 'er go! Maybe the fact that this occurs always without fail regardless of my state of physical exertion is a sign that I should never take up rock climbing!