Utthita Trikonasana || Ashtanga Yoga || 2nd posture of standing sequence

[@asharam686]

Nise

[@vishwarajput1307]

I have a question... i am practicing back band as you showed in your short video that you are gradually decreasing height and using a chair. I am practicing that for few days and i feel pain in upward area of my waist while banding back. So is that normal because i am a beginner or am i doing any mistake? Your reply will be appreciated.