Spring Has Sprung!?!?

As spring approaches (March 20, 2009, 7:44AM) here is an interesting article to get you thinking about putting that "spring back in your step" as you head outdoors...and tackle the yardwork!

This is the first part of the artical, "Spring has Sprung," by Mel Cheskin, MBS, C.Ped, from Current Pedorthics magazine, January/February 2008. For further reading you can continue the artical at: http://www.pedorthics.org/portals/0/JanFeb2008.pdf

While Einstein was busy extolling the credibility of
his Theory of Relativity another European inventor
was exploring the first recorded use of springs
in footwear. This is not really surprising, as springs became a
necessity in the production of the famed precision Swiss time
pieces and firearms from the 14th century onward. Mechanix
Illustrated magazine featured spring-heeled shoes in a 1939
edition, claiming to be the latest aid for “prolonging shoe
life and eliminating all jars to the various organs of the body
experienced by wearers of ordinary shoes.”

The shoes shown in 1939 were coil springs attached to a
rubber heel plate invented by a Swiss shoemaker. But there
have been several other spring formations placed in shoes
leading up to today’s latest entries into the marketplace.

A spring is a flexible elastic object used to store mechanical
energy, not all of which adhere to Hooke’s law: “The force
with which the spring pushes back is linearly proportional
to the distance from its equilibrium length.” Springs come in
numerous shapes and configurations:

• from helical (coil) to tension;
• leaf to catapult; compression (volute) to V;
• spiral to cantilever;
• Belleville to torsion;
• air to wave; and
• gas to rubber band

Materials can vary greatly too. Although one usually
associates springs with their metal forms just about any
material that stores potential energy can act as some form of
spring. Consider Nike’s compressed “Air” bag as a point in
question. Undoubtedly, the most successful shoe feature in
the history of footwear, Nike’s adoption of the Frank Rudy
innovative air bag patent in 1978 is, according to definition, a
form of compression spring.

More recently there has been a renewed interest in the
insertion of springs of all types into modern day footwear –
both for casual and performance uses. Why then, such an
interest in adding springs to footwear when so many other
materials offer better shock absorption?

The answer is in the other reaction to a soft cushioned
landing for the feet and body: namely, energy return. New
Balance had a great advertisement for its running shoes years
ago illustrating this point. The ads showed a runner wearing
two pillows strapped to his feet. The accompanying copy
stated, “What could be more comfortable than this?”

Without an adequate return or rebound of energy, once the
shoe has reached maximum compression, the shoe would
only aid the foot when landing. Springs are the most efficient
form of stored energy return. Of course, the balance between
shock absorption and energy return determines the ultimate
success of the mechanism placed in the shoe.

Let’s look at the latest spring-enhanced footwear offerings and
how their manufacturers are positioning them:

For the best care for your feet, please consult with Dr. Vail as to the most appropriate shoe to wear. For more information surf to www.vailfoot.com!