Injuries to your anterior cruciate ligament, or ACL, are some of the most devastating injuries in sports. To compound matters, the surgery to fix your ACL is traumatizing as well, with most athletes needed up to a year to fully recover. After ACL surgery, swimming is something you can do to ease back into exercise, as it helps you regain your range of motion without placing too much strain on your knee. Be sure to consult a physician or athletic trainer before resuming exercise after surgery.
Wait until your incision site is fully healed before attempting to swim. You will likely need your stitches removed between seven and 14 days after your surgery, but sometimes you may need to wait at least three weeks before getting your incision site wet. Until that point, you still technically have an open wound, and the pool chemicals or foreign particles from a different body of water can get into your incision site and cause an infection. Typically, you can start swimming after about three weeks, according to the University of Connecticut Health Center, but your doctor may recommend waiting anywhere from two to five months.
Use only the front crawl stroke to start out, after you get clearance from your doctor. Placing too much stress on your ligament can cause setbacks in your rehabilitation or even further damage to your ACL. The front crawl focuses predominantly on the upper body, with only a slight flutter kick for stability. If you can do this stroke with no pain, then consult your physician or athletic trainer about progressing to strokes where you would need to use a whip kick, like the butterfly or breast stroke.
Use a flotation device under your legs if necessary. This will help keep your legs at the surface of the water, so that you can swim with your upper body without your legs sinking in the water. This also takes the stress off your legs, allowing you to swim without aggravating your ACL.
If possible, swim under the supervision of an athletic trainer to help ensure you are not causing any damage to your knee.