Friday, February 24, 2012

Bike Safety: When Helmet Meets Pavement

Mary McDonald  RN, MSN, CPNP

Picture your child joyfully riding along on their bicycle.  Suddenly, the unexpected happens and your happy rider comes crashing down.  

Most often in bike accidents, the child’s head will hit the ground much harder than you would expect.  The force of this sudden impact to a cyclist’s head can reach up to 30,000 lbs per square inch.  This incredible force is transmitted to the child’s head over a very short time and can cause major injury to the head and brain.  Even a very low speed crash can cause a severe impact to the head and the developing brain of a child.  The picture below shows a bicycle helmet that was worn by a young girl who crashed while test riding a bicycle in the parking lot of a bike shop.  The child walked away without an injury.  As illustrated, the helmet did not fare as well.  Fortunately for this little girl, the helmet did exactly what it was designed to do: it absorbed the impact of the acceleration force to the head. Now imagine what might have happened if she was not wearing her helmet...

Numerous studies (2,3) have shown than proper bicycle helmets can reduce the risk of head and severe brain injury by more than 85%.  Many bicycle-related injuries to children occur to the head and face.  More than 120 children ages 14 and younger are killed in cycling-related incidents every year (4).  The majority of fatal injuries from bicycle crashes are due to trauma to the head.  The simple act of using a helmet could save your child’s life or prevent a serious injury.   So keep the following helmet safety tips in mind before you let your child ride away on their bicycle:
  • Make it a rule:  NO helmet, NO wheels.  EVERY time for ALL ages.
  • Use a hard-shell helmet.  These helmets are more protective than cloth-covered Styrofoam helmets.
  • Ensure the helmet is certified as safe by U.S safety standards.  Look for a sticker on the inside of the helmet from the CPSC (Consumer Product Safety Commission) or the Snell Institute.
  • Choose a highly visible color such as fluorescent yellow, highway orange or lime green.  This can increase a motorist’s ability to see your child by as much as 600 ft.(1)
  • Make sure the helmet is properly fitted.  See pictures below.
  • Adjust the chin strap so the helmet is comfortably snug.  Test the fit by wiggling and pulling.  If it slips or comes off, adjust the straps accordingly.
  • Ensure the chin strap is actually buckled every time.  Some children forget to buckle up!  Replace helmet if strap or buckle is damaged or worn out.
  • Replace any helmet that is involved in a crash or is damaged.  An impact to the helmet can crush the foam without leaving visible damage.
  • Model safe behavior by wearing your helmet every time you ride a bicycle!

A Real Life Example of Helmet vs. Pavement  

Soft covered helmet worn by young child test riding a bike.  Cover is partially removed to better show damage. This was a low speed crash.  The helmet absorbed  the impact forces and was shattered. The child was not injured.

Fitting a Helmet   

1. Green, James.  Bicycle Accident Reconstruction for the Forensic Engineer.  Trafford Publishing.  2001
2. A Buyer’s Guide to Bicycle Helmets. Bicycle Helmet Safety Institute, 2012. ,
3. A Case-Control Study of the Effectiveness of Bicycle Safety Helmets. Thompson, R.S et al, N Engl J Med. 1989:320:1361-1367.
4. National Safe Kids Campaign, USA

Special thanks to Jim Hoyt, Richardson Bike Mart, Texas and to  Anna Goddard, RN, MS, CPNP and Erica Brown, RN, MSN, CPNP-AC

Mary McDonald  RN, MSN, CPNP is a pediatric nurse practitioner with the Surgical Services department of Children's Medical Center at Legacy in Plano, Texas.  She is also an avid triathlete and runner.

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