I just posted the exact same question the other day. Hubby and I went kayaking on Sunday. We had some trouble getting them down off the car, and I caught the kayak awkwardly and it landed hard on my leg, and I felt a small twinge in my back. Then it was gone. My leg hurt, but you don't need legs to paddle, so we went out and did 7 miles of paddling. I was a bit sore in the shoulders that night, but the next morning I was ok. So I thought. I went to work, and moved wrong-BLAMMO! HORRIBLE muscle spasms, unable to drive myself home for about 30 minutes. Out of commission. It still hurts, but yesterday I was able to do a gentle walk, so long as I did not twist my torso. Today I went to the gym and used machines to work my lower body, and rode the sit down stationary bike. So far, so good. I don't know where your back pain is, but mine is in the middle this time, so I think the strained/torn ligament/muscle story is likely. Just don't get discouraged, and if you have someone to massage it, that def helps. Feel free to pm me if you want to talk about it. This is not the first time this has happened, and knowing me, it won't be the last.