I taught a few back pain relieving poses in a chair last week for one of my classes at The Yoga Circle Inverness. Here are pictures of some of the poses we did, per request of the students who attended.
Malasana in chair
Pasasana in chair
Bharadvajasana in chair
Paschimottanasana in chair: sit on edge of seat, grip seat with hands, fold at hips until you feel a stretch in your hamstrings.
Standing Maricyasana with chair
Virabhadrasana I, front foot on chair to emphasize control with the back leg.
Chair Downward Facing Dog
Upward Facing Dog, hands on chair
Hug knees, then savasana