GRADES 9-12
DESIGN A RUNNING SHOE FOR A TRIATHLETE

BACKGROUND INFORMATION: Tools Of The Trade As athletic shoes have evolved so has the technology to determine shoe and shoe related athletic performance. There are three basic types of analysis. The shoe industry itself monitors the structural stresses on the shoes. Athletic footwear undergoes a variety of laboratory testing to measure characteristics such as seam strain, adhesion (testing the adhesive used especially for new materials), durability, heat absorption, water permeability, shock absorption and even cold-flexing of winter boots. Machines have been designed to simulate specific conditions like toe drag on a tennis shoe. Gait equipment is used to study the overall performance of the athlete in the shoe and the forces the lower extremities encounter. Shoe manufacturers and gait labs also use athlete testers. Machines have been designed to test structural and wear components of shoes. This provides a benchmark- a method to determine under identical conditions how one shoe compares to another. The tests are repeatable and data acquisition systems can accumulate performance information. There is no doubt in the industry that these tests have improved footwear performance. Do machine tests reflect the dynamic motion patterns and actual forces the foot and leg encounter in the shoe? Early lab tests used prosthetic feet and legs (artificial limbs) with flatfooted impact. Different shoes would be placed on the device and results compared between different shoes. Although this same action could be reproduced, a common criticism was that few athletic motions are "flat-footed." Regardless of a standard comparison the motion wasn't realistic. University gait laboratories began using force plates and acquisition systems that could monitor true athletic motion. Force plates are used to measure the pressures encountered by the foot. Systems such as Novel's Emed, Pedar and Pliance measure the pressure distribution on the foot. There is even a Pliance system embedded in a saddle to analyze the pressure distribution on a horse's back. Today the athletic footwear industry and researchers use all methods available: specialized laboratory machine, objective athletic tests, high-speed photography, film and video. References Chang, W. and Seireg, A., Frictional Properties Of The Skin And Blister Formation, Third Symposium on Footwear Biomechanics, Tokyo, Japan, 1997. Cheskin, M. Sherkin, K. and Bates, B., The Complete Handbook Of Athletic Footwear, Fairchild Publications, New York, 1987 Cooke, A and Dixon, S., Sports Science and Engineering in Education: Sport Shoe Design, http://www.cookassociates.com, 2001-2002. Larsen, J., Slam Dunk Science, A Sport Research Lab In the Classroom, http://www.scire.com/sds/sdsmenu.html, 1995-2002. Novel, http://www.novel.de, 2004. Segresser, B., Injuries And Sport Shoe Design: Wish And Reality, 2001 Footwear Symposium, Zurich, Switzerland, July 5-7, 2001. Xia, B. and Robinson, J., 3D Kinematic Evaluation Of Footwear Stability In Lateral Movements, Third Symposium on Footwear Biomechanics, Tokyo, Japan, 1997. Thanks to Jim Pallis for the footwear graphics in this lesson. Sole patterns adapted from The Complete Handbook Of Athletic Footwear.