kula inwalidzka in English:

When she broke her leg she had to walk on crutches.

Since the accident Darek's been on crutches.

The man slowly climbed the stairs with the help of crutches.

Definition a crutch is one of a pair of long sticks that fits under your arm and which you use to help you walk when you have hurt your leg

The trick is to use English as a temporary crutch

I had twisted my ankle and I was on crutch. I walked with the help of a crutch