Hi, once at a yoga class the teacher told me that "if you can feel some bumps on your back (the vertebras), then it means your back is not straight". In GB terms, it should be "posterior pelvic tilt". I am doing the stretches series since 2 months now, and this is the best I can get without slouching my back.
Actually bending the back I can even touch my knee with my head.
Is this form ok? Is there a way to target just the lumbar part of the back when stretching hamstrings?