After the accident to Sri Aurobindo’s leg, we used to keep a big cushion under the knee as a support when he extended his legs while sitting on his bed. After about 30 to 45 minutes in that position, he would ask for the cushion to be removed.
One day he called me. I went and stood by his side and looked at him. He gave a surprised look and said: “Remove the cushion!”
I told him quietly that no cushion had been placed there today.
Then he glanced at his knee and laughed: “Oh … !”
Ref: Champaklal Speaks