Typical rafting injuries include trauma from striking an object, traumatic stress from the interaction of the paddler’s positioning and equipment and the force of the water, overuse injuries, submersion/environmental injuries, and non-environmental injuries due to undisclosed medical conditions (such as heart problems).[12] Studies have shown that injury rates in rafting are relatively low,[13] though they may be skewed due to a large number of unreported incidents.[14] Fatalities are rare in both commercial and do-it-yourself rafting.[12] Meta-analyses have calculated that fatalities ranged between 0.55[15] - 0.86%[16] per 100,000 user days.