Surfers often suffer from lower back and shoulder injuries thanks to constant paddling and lying in the prone position.
For example, being in a prolonged back extension can pinch the lower back area and if you let the abs relax when you’re tired, the tension increases. If you pull your navel toward your spine, press the pubic bone into your board, and lift your belly off the board, the lats and lower medial traps will work more efficiently and take the stress away from the lower back. The Gluteus Medius (pie shaped muscles on the lateral part of the hip under the Gluteus Maximus) is a key to stabilizing the pelvis on the board along with the pelvic floor and adductors. This combination of muscles grounds the body to the board but you do not want to execute this in a rigid way. Of course, you would have to practice this pilates technique and let the muscles get used to working that way so it becomes second nature, especially when you are tired.
The pilates system uses two key reflexes tilting and righting. Tilting reflex would be the reformer and the Swiss ball as the underneath surface is moving, this relocates the sea and water for surfers. Righting reflexes would be all the other equipment, the surfers can work specifically on a fixed surface challenging other areas and aspects of the body.
Shoulder and back muscles should be working together so the body is more efficient. If the muscles are working together you can harness your energy and use it to propel yourself and the board through the water more efficiently. You won’t waste good energy that you would need to catch waves. When you try to work with a disjointed body, injuries occur because the body will compensate for the weaknesses. The muscles that need to be strong are the rhomboids and your rotator cuff tendons. Yes, the lats and deltoids are crucial too. If you are overdeveloped or weak in those areas a shoulder impingement or tear will more likely to happen. Never thought lats and deltoids can be weak in surfers? Think again. The human body is a piece of art. Everyone is different and unique in the way they move.