Over the past twenty years, because of my work, I have frequently been called upon to give bicycle safety presentations to all types of audiences from kids to cops. When I give presentations to kids, usually at a school assembly, I will typically break it into three parts. This first part is the introduction where I quiz the audience to see what they know and correct any misconceptions. I also explain that helmets and gloves are you last line of defense against injury. Knowledge and skill are the primary lines of defense. If I am talking to adults I recommend they take a course or find a course on DVD like “Bicycling is More than Balance” If they don’t ride but have kids, I still recommend they find a course so they have the information, an idea of what skills are needed and how to teach those skills. The second part is a presentation on helmets and the third part is an age appropriate video. These three parts usually take about forty to forty-five minutes. The focus of this article is the helmet demonstration.
The Lead up to the Demonstration
When standing in front of an audience to to do my presentation on bicycle helmets, the first thing I ask the audience is for a show of hands from the people who think you need a helmet to ride a bicycle. My hand does not go up. You don’t need a helmet to ride a bicycle; you need it of fall. Your first line of defense in preventing injuries is being knowledgeable on safe riding techniques and being able to implement them.
Explaining How a Brain is Injured
Without trying to scare the audience I explain what brain damage means. I explain that you don’t need to crack your head open to have brain damage and that more often brain damage is small bruise on the brain. A ‘simple’ bruise can prevent you from tasting your favorite food or seeing again. The one fact that surprises most adults is that a sever bump on your head today can cause epilepsy later in life. I will also tell the story of my wife’s hairdresser. He borrowed a bike from a friend and was riding on the sidewalk and for an unknown reason he fell and hit his head. A blood clot was removed from his head the size of a grapefruit and he had to relearn how to do things we all take for granted like speaking and holding utensils to eat. The point of this story is not scare people into wearing helmet to show the usual excuse of I don’t ride in the street or I don’t ride near cars. You can fall off a bike anytime and you don’t need to be in crash with a car to need one. At this point I show what happens to the head during the fall and at impact.
After a brief explanation that the brain is supported by the spine and that it is surrounded by cerebral-spinal fluid; I ask the audience to imagine that the helmet I am holding represents a skull, my clenched fist is the brain and my arm is the spinal column. I center my fist in the helmet and explain that when a person falls the skull and the brain move as one and if the head does not hit anything or lightly hits something the brain is somewhat protected by the fluid and all should be well. As I am explaining this I am moving the helmet with my fist centered in it downward. I then explain that when your skull hits the pavement it comes to a sudden stop but, the brain floating in fluid keeps moving until it hits the inside of the skull, and if your head bounces, the brain can hit the inside of the skull more than once. I point out, that like the ripples in a pond, the cerebral fluid in the skull will produce ripples which also hit the brain and can cause more damage to the brain.
The Egg Drop Demonstration
Now that you have gone over some of the particulars of brain damage and the audience has an understanding of how brain injury occurs and realizes how easily the brain can be injured. I begin the helmet demonstration. I used to use a bicycle helmet and a cantaloupe because the cantaloupe is about the same size and weight as a head I thought this would be a realistic demonstration but, between the cost of the cantaloupe and replacing helmets that cracked; it just got too expensive. Now I use eggs.
There are two parts to the demonstration. Part one issued to demonstrate a protected head and part two the unprotected head. For this you need the supplies listed below.
1. Three eggs (not hard boiled)
2. 1 box of styrofoam packing peanuts or sand (clean with no rocks or sticks)
4. Sharpie Marker ( optional)
5. A table with a hard surface (optional)
Part one: The Protected Head
The physical set up is simple. Put newspaper on the ground and the box of sand or packing peanuts on the paper. Make sure enough paper sticks out from under the box to keep the floor clean case you miss the box when you drop the egg.
This part requires a little audience participation. You show the audience the egg to make sure there are no cracks. You spin the egg to show it is not hard boiled, If it wobbles its a raw egg. You may want them to look in the box to show them you are not trying to trick them by hiding a second egg in the box. If your audience is kids ask them to name the egg. While there yelling out names draw a face on the egg. With face drawn and your egg named you hold the egg at chest level and ask the audience if you drop the egg in the box will it break. You then raise the egg higher and higher until you can’t go any higher before you drop the egg into the sand. Typically, I try to raise the one or two feet beyond where the audience thinks it will break. I have stood on a chair at the edge of stage and dropped the egg from ten or eleven feet high feet. Speaking from experience I can tell you that this does dramatically increase your chances of missing the box or hitting the edge and gives you a great opportunity for some theatrics about missing the box and splattering the egg.
Once you’ve dropped the egg, have members of your audience check it for cracks. if the egg hasn’t cracked, you’ll use it again for the second part of the demonstration. If the egg does have some small cracks put it aside and use a fresh egg for the next part.
Part Two: The Unprotected Head
For this part, remove the box and just leave the paper on the floor or if you have a table put the paper on the table and use it for the demonstration. This will make it easier for the audience to see the drop. Hold the egg over your head and ask if you drop the egg on the table or floor will it break. You continue to ask this question as you lower it closer to the hard surface. When you are about six inches from the floor the answers will be mixed. Keep lowering the egg to about four or five inches and then drop it. The egg will crack. sometimes it will dent or it may even split apart. Once again ask the audience to inspect the damaged egg. Compare the contents of the box to wearing a bike helmet. The sand or styrofoam dissipates the energy from the drop throughout the sand just like the styrofoam of a helmet. If the first egg cracked compare how well the sand or styrofoam protected the egg from the height you dropped it to how easily the other egg easily damaged from only four inches.
At this point I inevitably get a question about why adults don’t wear motorcycle helmets. The only I answer I can give is that some times adults don’t make the best decisions.