If your knees start to hurt, it's crucial to adjust your stance to alleviate discomfort. Firstly, ensure your weight is distributed evenly between both feet, and your knees aren't locked, but slightly bent. Pay attention to the alignment, your knees should be directly over your feet when you bend them. Regularly stretching and strengthening the muscles that support your knees can also help reduce pain. Lastly, remember to listen to your body, if the pain persists, it might be time to seek professional advice.