In fact, you need to distinguish between two specific situations:
If you are in a "flare-up episode of osteoarthritis", that is to say when a joint is hot and swollen and more painful than usual it is recommended to rest the joint. This means for a knee or hip, for example, not putting weight on the affected side but to use crutches for walking during the painful period.
But apart from these flare-up episodes, it is imperative to get regular exercise. Movement is beneficial to the cartilage as it allows it to improve its nutrition and stimulate its cells. It is thus advisable to walk for at least 1 hour, 3 times a week.