Pit & Quarry, April 2013

BY CARL METZGAR Lawn mower injury analysis T he Journal of Trauma published an article in 1975 titled The Wounding Capacity of Rotary Lawn Mowers The fact at that time was that the kinetic energy in a 26 in blade was equivalent to the energy stored in a 21 lb weight dropped from a height of 100 ft This was supplemented by the fact that the momentum of the mower blade referenced to its tip equals that of a 117 lb weight traveling at 232 mph A 2013 article reports that more than 83000 lawn mower injuries occur each year in the United States The number of injuries from walk behind mowers declined after certain safety features were mandated But even with a reduction about 75 people die each year from lawn mower injuries Considering the population of the United States these numbers are small but they can be smaller Occurrences in aggregate plants are rare too but keep in mind that the plant beautification projects added to an area have to be mowed Another article states that the injury rate for ride on mowers is 26 injuries for every 1000 ride on mowers per year That rate is three times greater than the injury rate for walk behind mowers About 8 percent of deaths related to ride on mowers involve passengers age 6 or bystanders age 4 About 5 percent of injuries that occur during the use of ride on mowers and 7 percent of deaths related to ride on mowers occur when a person is run over or backed over Of these injuries 85 percent occur in children between 15 months and 10 years of age The Consumer Products Safety Commission reported in THE INJURIES ARE CAUSED BY CONTACT WITH THE BLADES PROJECTILES THROWN BY THE BLADES BURNS FROM HOT SURFACES 1999 that despite the dangers of riding mowers a government survey showed that 55 percent of households with riding mowers and with children less than 10 years of age allowed their children to ride on mowers The injuries are caused by contact with the blades projectiles thrown by the blades burns from hot surfaces burns from gasoline fires and overexertion in older males using push mowers The injuries are lacerations abrasions penetrations fractures amputations and in one particularly devastating case life altering disfigurement to a 2 year old girl Naturally there are what ifs A 13 year old male experienced a sting in his chest that he thought was a bug bite The next day the reddened area prompted his mother to take him to the emergency room where a metal pin 5 cm long and 3 mm in diameter SPONSORED BY Many areas in aggregate plants need to be mowed because of beautification purposes or other reasons Fortunately few mower injuries happen at such plants was removed from above his sternum Consider that many areas in aggregate plants to be mown are aside the roads delivery trucks frequent There is no telling what gets thrown from trucks that can wind up as projectiles Foot injuries are very common and represent a serious reconstructive challenge to a plastic surgeon Even a casual glance at a cutaway drawing of the foot shows a complicated compact collection of bone muscle nerves veins and surfaces to be put back in order The plant safety requirement that miners wear steel toed shoes can be supported by a suggestion that the shoes be worn at home while mowing The preventive measures for mower injuries are easily available on the web But the devastation to children is easily prevented Keep them out of harms way They belong in the house They cant ride on a mower if they are in the house If they are in the house they cant be backed over Also to be considered is the matter of footwear Steel toed shoes are far superior to tennis shoes during mowing And of course dont let other miners stand around while someone is mowing P Q Carl R Metzgar CSP has more than 30 years of safety and health experience in the aggregates industry He provides consulting services with a specialization in program evaluation training compliance and loss control and can be reached at 336 766 1218 cmetz46840@ aol com 48 PIT QUARRY April 2013 www pitandquarry com