Please help me with this possible injury - you will need knowledge in anatomy?

[Dean]

I was in my college gym and I got onto a rowing machine. The person using it before me had left the handlebar up and I couldn’t reach it straight ahead. When I was trying to reach it the person rowing next to me without saying anything gave me a sudden hard push forward, and I felt about two crackles (kind of like the feeling of joints crackling) toward the left of the my hip area (because he was on my left). After doing a bit of my own research, I think it was even more to the left than the sacroiliac joint and I’ve never felt a crackle in that area before, even when I mimic the action, so he must have really pushed me way out of my range of motion. I’ve uploaded a photo showing to the best of my memory where I felt the two crackles. I didn’t feel pain at the time, so please tell me if it could have been; nerves, tendons, or muscles snapping or tearing, bones breaking, tendons or muscles passing over each other, etc.
http://img91.imageshack.us/img91/1534/skinmaleposteriorwebwz7.jpg
I didn’t really notice any pain (just a stretch in my lower back when I lied down) for days. This happened on a Tuesday afternoon and I didn’t really feel pain until a Friday afternoon/Saturday morning. I want to know if the pains and symptoms I’m feeling now could because of something else, like some stretches I did later or stress, this incident. The symptoms that have come on since Saturday have been lower back pain, some leg numbness, and right now mainly experiencing the need to go to the toilet often and less intense orgasms and no morning/nighttime erections. Thank you.