Biomechanics - Triathlon Week

Robert G. · 12-27-2002, 10:49 AM

Biomechanics Explained
Face it, your feet are two tremendously complicated mechanisms. They're built mainly of bones, tendons, muscles, ligaments and skin, and they're engineered to endure the punishment of everyday living without discomfort or complaint. But they're not perfect, and the shoes you choose can do a whole lot to make their life more pleasant and rewarding.

To best understand how Saucony shoes are so carefully designed to meet the biomechanical needs of your feet, let's take a quick look at the punishment a runner's feet must undergo. (And even if you're just walking, these principles still apply.) There are three phases a runner's foot passes through with each stride. Here they are, one by one.

The Rearfoot Phase
Each time your foot lands on its heel, it undergoes considerable shock. The strain is taken up by the heel bone (calcaeneum), which reacts by first rolling, then swaying, then finally tilting slightly over toward the outside of the foot. The actual shock of heel contact creates an impact of up to three times body weight. All this impact is transmitted upward toward the leg joints. Now you know why runners can experience such serious strains in their ligaments, tendons and joints.

The Midfoot Phase
As the runner's body weight shifts forward, the foot then moves into the midfoot phase, with the force shifting away from the heel toward its midsection. The arch of the foot splays out, with the sole taking up the entire weight of the body. Then the foot rolls forward onto the metatarsals, bringing with it a torsional or twisting effect. This sometimes forces the foot to tilt toward the inside (pronation) or to the outside (supination), placing new strains on the joints and ligaments. This rolling motion lasts about 2.5 times longer than the rearfoot phase.

The Forefoot Phase
Here's where the foot really feels the pressure. As the foot continues to roll forward and the runner's weight is transferred to the metatarsal bones in the forefoot, the force exerted actually increased to between four and seven times body weight. (That means the foot of a 150 pound runner can be called upon to support a weight of a thousand pounds or more!!) The spread of muscles across the metatarsals distributes the stress across the whole width of the forefoot, absorbing the surge of power that propels the foot off the ground for the next stride.

Source:
http://www.saucony.com/

Raoul in L.A. · 01-12-2003, 06:20 PM

whats your thoughts on this?