Near the top she felt something give way and her knee cracked hard against the concrete.

My knees cracked into the pavement and pain shot through me.

Her knees cracked against the instrument panel several times, and then they stopped suddenly.

Try not to be too sensitive to the sound of your knees cracking and heavy breathing.

He came forward, his knees cracking at each step.

I drop, my knee cracking like a pistol shot, from somewhere deep inside.

His knees cracked and he pitched forward on them.

He hobbled over to the opening, his knees cracking loudly, and called her name.

She sighed, and stood, her knees cracking as she did so.

Rick's knees cracked as he knelt at the grate to start the fire.