I sat down in a chair because my legs had given way.

His legs almost gave way under him as he stood.

I tried to take a step forward, and my leg gave way under me.

He started down the mountain and his legs gave beneath him.

His legs gave way and he pitched to the earth.

She lowered herself onto a step before her legs gave way.

His legs gave way, and he did not feel himself hit the ground.

At the thought of how short a time that might be, her legs nearly gave way.

His right leg no longer gave him support, but he was beyond feeling any pain in it.

His legs gave, and he found himself sitting on the ground.