I had to sit down as my knees began to shake.

But his right knee began to bother him, and he missed seven games.

My knees began to hurt on the hard concrete floor.

Her knees were beginning to feel shaky, and she pressed them together.

Martin ran through inside, but it was too late for Rachel: she couldn't see, and her knees were beginning to give way.

My knees began to tremble from the need to walk.

He heard Terry say something, felt his knees begin to buckle.

The next day, though, her knee began to swell, and she decided to come to the hospital.

I tried to remain standing, but my knees began to buckle.

We parted as the sun and our knees began to sink.