Poses to Avoid: Yoga for Low Back Pain

Seated Forward Bends
You should avoid sitting forward bends, especially if you have a history of lower back pain or injury, until you can stretch your leg straight up to 90 degrees or more. If you are in a class where forward bends are being taught, you can always substitute some simple leg and hip stretches like Supta Padangusthasana (Reclined Hand to Toe) and Supta Baddha Konasana (Reclined Bound Angle Pose). – Julie Gudmestad
Some Poses Not for Those with Back Pain
Ancient yoga texts suggest asanas like Navasana (Boat Pose) to strengthen abdominals, Paschimottanasana (Seated Forward Bend) to stretch the hamstrings, and Salabhasana (Locust Pose) to strengthen the back muscles. These are strenuous asanas. Many fit people cannot do them as they are depicted in the yoga texts, let alone a person suffering from back pain. Such asanas are suggested with prevention in mind, not as therapeutic measures. They are the goal, and the asana program must aim to gradually lead the person toward these asanas. Attaining the ideal may never be possible for a particular person. That does not matter. What is important is progress toward the ideal. – A. G. Mohan