My Breathing Back

The type of pain that I consider 'back breathing' is kind of like throbbing pain, but has a slower, more deliberate kind of delivery.
It doesn't necessarily follow the pattern of your breath, like throbbing pain does with your own heartbeat, but it's this sort expanding feeling - and not in a good way.

Last night I had some of this back breathing pain that was really intense. Felt like my SI joint and my hips were expanding and contracting inside my body all on their own. They had their own rhythm and each time they 'expanded', all the muscles surrounding the joints partially seized up. Slow deep breaths of intense back pain.

Very weird.