She hit the wall, feeling her legs buckle from the impact.

All the color went out of the man's face, and his legs buckled.

When he tried to stand, his legs buckled under him.

Paul tried to force himself up another step, but his legs buckled.

When he looked over the edge and saw her, his legs buckled.

Then her legs buckled, and she fell to the floor.

Frank hit him over the head from behind, and the man's legs buckled!

He felt his legs buckle and give with each step, like a puppet's.

Suddenly her legs buckled and she fell to the snow.

The legs on one side of the table buckled and almost collapsed.