jerk up and down

Some other species, though less elegantly adorned, make a pleasing variety in the microscopic scene; and appended to some of the threads is a group of small crystal bells, which jerk up and down upon spirally twisted stalks.

Even so, the window into which you're typing will jerk up and down in the most distracting way as the autocorrect list appears and then goes at the end of every word.

The entire cockpit began to shake and jerk up and down, and suddenly tilted all the way on its back, nose pointing up.

A long scraggy tail was stuck on behind, which by an ingenious device could jerk up and down and from side to side.

Someone on the bridge of the distant cruiser might almost have heard his remark, for as he spoke the halliards began agitatedly to jerk up and down to allow the bunting to flutter clear.