The rotary lawn mower possesses a powerful wounding mechanism. A typical 26-inch rotary mower blade rotating at 3,000 revolutions per minute develops a kinetic energy of 2,100 ft lb. Wounds may be inflicted by direct strike or by missile action due to a broken blade or other mass. Other serious injuries due to crushing or upset are commonly seen with self-propelled mowers. Ways of reducing these risks are enumerated.