Contraction Confusion

I'm experiencing two different types of contractions and in order to relate them to what's happening to everybody in the forum, I need some insight:

1. The first type of contraction is when I insert the aneros and the rectal muscle is trying to pull the helix inside of me. That is an involuntary contraction.... correct? I feel these individual contractions for a while until the next contractions happen. I think that this contraction is just getting used to the foreign object inside of me.

2. The second types of contractions are the fun part: hips are bucking and the helix feels like its moving in and out, super-fast at times. These contractions last for 2-4 minutes at a time, and I can get them going at anytime by moving my hips. All of this by laying on my stomach.

I assume the two are similar, but the second type make things interesting. Any insight?