As a form of hydrotherapy, swimming is one of the most recommended exercises for treating musculoskeletal injuries, especially those affecting the spine.
Not all forms of swimming are good for the spine, however. Depending on the area affected, certain practices benefit recovery, while others can cause complications.
With inflammation or an injury in the lumbar region (the lower back), butterfly and breast strokes should be avoided. The recommended strokes include backstroke, which does not put strain on the natural shape of the back, and freestyle, although you should be careful to avoid kicking your feet too low in the water and placing more pressure on the lumbar region.
With scoliosis, or a sideways curvature of the spine, exercises that make your weak side work are suggested. Examples include: swimming with your non-dominant arm while keeping your other arm still alongside your body; swimming freestyle with a fin or hand paddle on your weak side can make it work harder; and doing U-turns instead of flip turns along the wall on the side that puts your weak side to work.
Not stretching, not stretching enough, over exerting yourself, or using poor swimming technique can all contribute to pain.