RedactedNarrative: A family of four was tubing on Deep Creek Lake in MD.  They had rented a 17 foot Bayliner and the son and father were on tubes, with the daughter as lookout and mother operating.  A wake caused the father to fall off the tube.  The force of the water bent his knee outward.  He decided he would wait until the next day to see how his knee felt.  the next morning, realizing his knee was swollen, he drive himself to the local hospital for an examination and MRI.  He was treated and released for a sprained knee.
NameOfBodyOfWater: Deep Creek Lk
NearestCityTown: Oakland