Best Grip For Stretching Up Towards Belly?

Hey, I’ve been doing manual stretches, the upward stretch seems to be the hardest one to keep.

Any suggestions?

5-28-16: NBPEL 5 & 8/16. BPEL 6 & 3/16. Mg 4 & 4/16.

10-17-16: NBPEL 5 & 8/16. BPEL 6 & 6/16. Mg 4 & 8/16

Goal: NBPEL 7x5.5