The strength went out of his legs, and he sat down suddenly.

Suddenly all the strength went out of his legs and he sat down hard.

All at once the strength ran out of his legs and he sat down again.

The strength ran out of his legs in exactly the same way.

Now all the strength ran out of her legs and she sat back down on the bed again.

I'm humming along, as if the lead had been taken out of my legs.

I had quite the chunk taken out of my leg.

As the pain worked its way out of her leg, she picked up speed.

The strength went out of the man's legs and he slumped forward.

She walked about to work the stiffness out of her legs.