Body Levers (FL PE10 Step 6) - What to use as should/upper back support so I can go to/or past parallel?

I've been trying to find different equipment to help me finish this step. I have been using that half exercise/stability ball with the flat bottom however not every gym has one. I travel a lot and was wondering if anyone had any ideas for what I could use instead that is commonly found in most gyms or stores. 

I have been laying on the ground and using my hotel bed as a counter weight but I know that I am not getting the full workout since I am hitting the floor and not able to go past parallel. 

HI Samuel, can you post in the private forum a form check? so that I can really see the problem?

You can set up a flat bench parallel to a Smith machine bar loaded with some weight, rest the shoulders on the bench. 

Less ideal a lat pull down machine can be used in a very small gym that doesn't have access to a Smith machine.