The American Academy of Orthopaedic Surgeons offers these recommendations to prevent swimming injuries:

• Before jumping or diving in the water, warm up with some stretches, walking, running, biking or even some jumping jacks for a few minutes.
• To prevent repetitive motion injuries of the shoulder, start an exercise program designed to strengthen shoulder and upper back muscles.
• Take swimming lessons. And never swim alone.
• Avoid swimming when you're overheated, too cold or just too tired.
• Don't swim strenuously if you're sick with a fever, an upper respiratory infection or an ear infection.
• If diving, make sure the water is safe and deep enough.
• Carefully clean and dry ears after swimming to prevent swimmer's ear infection.