I am no medial expert, but I once managed to get some horrible back pain after playing with my then 3 year old daughter. I still don't know what I did that was so bad as I have never before had back problems. I called the local massage school (NY Institute of Massage) and got in that morning. They are realy cheap ($30 for a full hour) because it is the student clinic, they are good and keep close tabs on the students. They always ask if you have any problems, and then they do to work. They did an amazing job. The next day there were no more problems. Chiropracters scare me a little (probably unreasonable), but the whole "cracking the spine" bit is just off putting. Some of my friends swear by their chiropracter. A good deep tissue massage can do wonders for when you've pulled something a little wrong.
Consider adding some Pitates or Yoga to your excersize routine if you have back problems. It is amazing how intensive the workout can be and all you do it more your arms and legs "a little." I haven't been going to the club as I now ride my bike 5 days a week to work. I realy need to add some Pilates back into my workout because it is an amazing core streaching and trengthening workout. I work on my family's cars frequently as I will do just about all the mainetenance and in the past I would get a neck ache from replacing an exhaust system or some other task that has you under the car for an extended period of time. Once I started the workouts my neck, back, and abs became so much stronger that I no longer had body aches after the car work.
Good luck and heal soon,
André