膝盖 (xī gài): 膝

I fell while playing soccer yesterday, scraped a large patch of skin off my knee, and it hurt so much I couldn't stand up.

Grandma's knee hurt for several days, making it especially hard for her to go up and down the stairs, so the doctor advised her to walk less and rest more.

When practicing tai chi, the coach reminded us to slightly bend our knees so we could keep our balance and avoid injury.

My little sister ran too fast and banged her knee on the corner of the table; it immediately swelled up, and Mom quickly brought an ice pack to put on it.