From position 5 (Parivrtta Uttanasana) the top arm reaches forwards, in line with the spine with he palm facing down to the floor. As the arm reaches forwards one knee will likely try to bend bringing one hip forwards. I like to allow this to happen until I find a comfortable arm position then attempt to even the hips up with the next exhale breath. Hold the position for 3 breaths and really try to straighten the arm and make it parallel to the spine.
As with all these exercises, make sure you check with a doctor you are OK to do the stretches. Move gently and slowly with the breath and if you have any pain or health worries go to the doctor.