Leg starts shaking by itself

My leg always starts to bounce up and down by itself when I sit & press my foot down like tiptoe. But when my foot is flat its fine. Is this normal for it to happen?

Thanks

You might have stress and or a potassium deficiency in your life. Go do some weight-training for a week, and eat a lot of potatoes.

Also, more magnessium supplements. If you drink coffee very often, you should either drink less or just stop it. Eat dark chocolate and have a good sleep

restless leg syndrome