Ramesh,
General terms do not beget specific and accurate replies.
When the student says “back pain” there are a myriad of questions a good yoga therapist would then ask. Some low back pain is muscular. Some low back pain is actually an issue in the low front. Some is due to being sedentary while some is due to being active in an aggressive, careless, or mindless way.
Each of these, for a Yoga therapist, has a different approach AND none of those approaches are ONLY asana. While we do live in a world of prescribing something which makes pain “unfeelable”, asana is not one of those pills.
If you care to expound on the issue that would be helpful. Such a sharing would include the location and nature of the pain, it’s frequency and duration, what makes it better and worse, and whether it is more painful in the morning/evening and when standing/lying down.
gordon