Is the pain there while you are swimming or is it there after you stop?

The only thing that I can think of is that you might be allowing you hips to sag in the water a little bit. This is put some strain on you lower back. Other than that i can't think of what it could be because swimming is usually a fairly pain free activity.

Also, do you lower back pain while biking or running, or is it only while swimming?

It could be lower back/core weakness. You need to keep your abs and lower back somewhat taught in order to keep your body in line because there isn't much support in the water. If you loose that you end up stressing your back.

Huh maybe that's why I feel it more when I'm not riding as much.

Thanks for some of your thoughts.

Funny thing is that everyone keeps telling me that swimming should be good for your lower back.

My pain begins in the water and as I increase laps it gets more painful. There is generally no pain when running or biking.

I don't think it's becasue of core weakness as I do quite a bit of core and back exercises.

Can you eleborate on pushing down with the chest?

The other thought I had was that it was casued by the rotation of my body on the stroke -in other words my upper body rotating to breath but my legs not enough and therby causing some torque. No idea how to prevent though.

In any case, I am close to calling it quits with self diagnosis and checking with a doctor - I just worry I'll hear the lazy doc answer:

Stop swimming.

It sounds to me like an irritation leading to mild inflammation which causes the nerve pain and stiffness.
You say you have a hard time bending when it is painful. I'd be curious if you can do this when you are sore. Sit in a chair, extend one leg straight . Then back down. Then the other leg straight out and back down.
I had a serious misalignment at Vertebrae L5 a number of years ago. This was the test that finally showed me how serious my problem was. I could only extend my right leg to about a 45 degree angle before my back would cause so much pain it would spasm.
Chances are your problem is not that bad. The exercises I do now to help with my lower back. Which may help you.
Yoga Triangle pose. For me seems to create space at my hips and also movement for my lower vertebrae. I'll often hear a pop as I go into this pose.
Cobra pose and Superman. These are more for strength building.

I typically go to a chiropractor once a month now. It's preventative maintenance at this point. Not to mention how much better I feel after an adjustment. Not quite a massage but it's close.

Hope you figure it out. Good Luck

well you may want someone to look at your technique. proper technique should not cause pain.

A second idea is to work on your flexibility. i learned in my athletic training class the other day that one main cause for low back pain is poor flexibility. try stretching before and after your swim. expecially your hamstring muscles.

If back pain happens only as a result of swimming then have someone look at your technique. You dont want to cause an injury from improper technique.

good luck

P.S when stretching to IMPROVE flexibility you must hold the stretch to mild discomfort for 30 seconds. Repeat the stretch 3-4 times. :)

I went swimming yesterday and tried to concentrate on keeping my upper torso a little lower. I also did alternate with drills using a pull float. It seemed to help and I did not experience any pain. I'll have to keep with it and develop my muscle memory.

Thanks.