** EDIT ** To clarify, below is a feature that will be in the NEXT update to Ouch!, which will be version 1.2 ***
We are currently working on the next update for Ouch! (v1.1.1, which fixes some bugs and adds a few new props is currently in review with Apple), and one of the new features we are adding is the ability to alter the gravity for your custom scenes.
You can change the strength of the gravity (from zero to twice the default gravity), the direction of gravity, and also enable a new mode that lets you control the ragdoll by tilting in ALL directions, not just left-right. This is especially useful for zero-gravity scenes, where you can slide the ragdoll all around just by tilting.
We still have some other features to add before we submit the update that includes this feature, so we will post again as we get closer to submitting!