Swimming is, by most standards, not a sport associated with high risk of injury. It does however have its own set of challenges. By far the biggest source of swimming injuries is in the shoulder.
Overuse is often what doctors will give as a reason for swimming shoulder injuries, but this is a pretty general term and doesn't help many athletes when they're trying to accomplish their goals and avoid getting hurt! Below are some preventative measures you can take to avoid a swimming shoulder injury of your own.
Establishing Proper Form
One of the most important things in stroke technique when it comes to freestyle and avoiding shoulder injuries is to bend your elbows underwater during the pull. This is proper form and will keep you from putting your shoulder in an awkward position that leads to a rotator cuff problem.
When you've had some time away from swimming and are resuming training, always ease back into it. If, for example, you train with weights and had a 3-month layoff, you wouldn't try to max out on your bench press the first day back. The same applies to swimming. Instead of jumping back in and resuming the 5,000 meters you were doing before your break, start with something very light--like 1000 the first day, 1200 the next, etc.
Avoid the use of pull buoys and paddles. Although it is tempting, buoys merely give you a false sense of flotation and put unnecessary tension on your joints, especially your shoulders. Although there are paddles designed not to cause shoulder problems, most of the paddles out there are not needed in training, and will cause shoulder problems if you give it enough time.
Diversify Your Workout
Swimming only freestyle at all of your workouts may seem like a good idea if you are training for a triathlon, but I would not recommend it. First of all, you will gain more from cross training with other strokes. And most importantly, excess in any one stroke leads to a higher probability of an overuse injury.
If you breathe to only one side, you will develop the muscles more on one side than the other, and this could cause a breakdown and a shoulder problem. Incorporate bilateral breathing into your workouts to avoid this. If its extremely awkward at first, start with just breathing bilaterally in warm-up and warm-down, and slowly add it into the rest of your workouts as it becomes more comfortable.
If you are just getting over a shoulder injury and are jumping back in the pool, put on a pair of fins. Zoomers or Hydro Finz work the best. That way you are accomplishing three things: 1) taking some pressure off your shoulders, 2) getting a great cardiovascular workout, and 3) building strength in your legs for swimming.
One good thing about shoulder injuries is that they force us to slow down, and give us a chance to work on drills and stroke technique while we get back to health. And from what Ive seen as a coach, many athletes can use a little slowing down when it comes to improving their swimming!