I believe 'forward' is the lightest of SPRING PRELOAD setting, which is what this handle is for.
With the handle 'rearward', the springs will be at their stiffest, and least comfortable, but better able to handle heavy loads.
But the bottom line?
If you still have these shocks on youe bike, you need to replace them. They were marginal at best, when they left the factory.
Do a search in this section for "shocks", and you find plenty of suggestions for replacements.