Ski Binding Safety – Part II
Posted by John Sedgewick - 12/08/10 at 05:08 amExploring how elasticity is a factor in alpine ski binding design and performance is not easy because there is very little written about it, and because few people outside of the ski binding manufacturers have studied it.
The very concept of elasticity in ski bindings is unknown to most skiers. To understand it, you must realize that the connection between ski and ski boot is constantly subjected to high forces during skiing. It is, after all, only through that connection that the skier is able to control his speed and direction. Also, one must realize that it is not force alone that breaks bones, but force exerted over time. Leg bones can withstand very high force levels without breaking as long as they are exposed to those forces for only a very brief period of time. This is true because of the capacity of the bones to bend. If the bending force is imposed and removed quickly, the bone absorbs the force by bending and straightens out again, and the skier continues down the mountain.
Because his bones can absorb spikes of force, a skier can ski through bumps, ruts, caught tips, and other events which cause forces on the leg to spike briefly. If the binding is not able to tolerate these spiking forces, it will release even though there is no risk of breaking a bone.Even in normal skiing forces spike so often that frequent releases will occur in non-elastic bindings, spoiling the fun of skiing but also, and more importantly causing the risk of major neck and head injury from inadvertent release.
Thus, to be safe and useful, an alpine ski binding must be able to absorb brief spikes in force without releasing. If it can do that, it is said to be elastic.
