this appears in this month's 220 Triathlon Magazine and I'm pretty sure it describes exactly my back problem:
" Lower back pain in both swimmers and triathletes is caused by repetitive stress, particularly if you fail to roll your body as a whole unit while swimming. This failiure to roll correctly creates torsional strain at the point where the lumbar spine meets your pelvis. Poor body roll may mean that you arch your back to clear your head from the water, leading to stress on the facet joints at the back of your spine.
If you've developed excessively tight hip flexor muscles, you may have reduced your ability to fully extend your hip during kicking. This tends to tilt your pelvis in a way that over-arches the small of your back. Again, this can overload the facet joints, causing pain...
Poor core stability and weak gluteal muscles are also contributing factors, and it's important to consider making stability exercises, or pilates-based exercises, a part of your regular training "
Will maybe we can discuss this when I see you on the 19th. I'm thinking I'll need a massage then and we can maybe do some exercises to loosen off my right hip? Maybe you could point Kathryn in the direction of this article when she returns?
Since seeing her I felt completely cured, then started doing more swimming and the problem has returned. At least we seem to be narrowing it down !!