Whether the knees are arthritic or injured, Pure hot yoga will definitely help. You must move the knees to get circulation to them, and Pure hot yoga helps you do both.
So how should you proceed? Make sure to listen carefully to the alignment instructions in each posture. When you are told to keep your feet parallel in standing postures, please do so. A half inch in either direction away from parallel has its effects all the way up the knees and into the hips.
In standing balancing postures, it is also important to keep the standing foot straight and the standing knee pointing straight ahead. If your knee bows back (hyperextension) you should bring the weight forwards towards the toes so as to engage the quadriceps muscle and lift the kneecap upwards. This action brings the leg into one line and brings true strength to the knees.
When you are bending your knees in any of the standing postures, keep the knees pointed over the toes. This will ensure that the knees and hips are strengthened evenly inside and out.
In triangle, when you are told to push your hips forward as you bend your front knee, this will keep your hip in line with your knee in line with your foot. This is also good for even strengthening of hip and knee joints.
In some of the standing postures, it might be very difficult to bend your knee to a 90 degree angle. So do the best you can without creating pain. Better to keep proper alignment.
In the floor poses, notably fixed firm, half tortoise and perhaps rabbit, it might be difficult for you to bend your knees enough that the hips sit on the heels. To test your knee flexibility, keep lots of weight in your hands and bend the knees gradually to the point (but not past) of pain. You must be able to relax and breathe in the posture, holding it steady, for anything to happen. As the pain decreases and you start feeling more comfortable, you can gradually take the weight out of your hands and allow more pressure on the knees. Eventually you’ll be able to go all the way into the posture, and you won’t even remember the time when you couldn’t even sit down!
You’ll find that little by little your knee pain goes away and soon you’ll realize that you can walk, climb up and go down stairs, even run a little without pain!