Jens Heidenfelder

Systematically modified crash-pad reduces impact shock in running shoes

The purpose of this study was to compare the effect of (a) crash-pad thickness and (b) midsole height at the heel to reduce heel impact load during running. Twenty male runners performed heel-toe runs in four different shoe conditions. While three shoe conditions had systematic changes in crash-pad thickness without changing general heel height, a fourth shoe condition differed only in overall heel height. Kinetic and kinematic running variables were quantified by using a force platform and an electrogoniometer. Data were collected for five valid running trials at a constant running speed of 3.5 ± 0.1 m s−1. Kolmogorov–Smirnov tests, a one-way repeated measures ANOVA (P < 0.05) as well as effect sizes (η 2) were calculated for all variables. The findings of this study showed that (a) increasing crash-pad thickness resulted in reduced impact variables without influencing traditional rearfoot motion variables. Furthermore, reduced heel height (b) is influencing predominantly rearfoot stability. Consequently, crash-pad modification can be used to improve cushioning properties without influences on rearfoot stability. Furthermore, crash-pad modification allows reducing shoe weight while maintaining cushioning properties.

Biomechanical wear testing of running shoes

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Heel strike angle and foot angular velocity in the sagittal plane during running in different shoe conditions

Runners change their running style, e.g. heel strike strategy, to adapt to different shoe conditions [1]. Various mechanisms for adaptation are discussed [2,3]. Alteration of stiffness of the ankle joint at heel strike by dorsiflexion or plantarflexion of the foot seems to be disregarded as mechanism of adaptation. In this study, alterations of heel strike angle (HSA) and plantarflexion velocity (PFV) in the sagittal plane due to wearing different shoe conditions was examined. By this, adaptation in running style as a mechanism of shock attenuation should be investigated.

Running shoe properties during age: a comparison of two different approaches

the materials (PU and EVA) were not as clear. The results for average contact area for medium density PU suggests a possible difference in the loading characteristics of the material with it appearing to conform more with pressure therefore spreading the load over a greater area. This indicates that PU medium density may be a suitable material for patients with a compromised ability to deal with pressure. Acknowledgement

Mechanical and biomechanical characterization of running shoes with different midsole materials before and after aging

Karoline Brueckner*, Jens Heidenfelder, Stephan Odenwald and Thomas L. Milani Chemnitz University of Technology, Sports Engineering and Technology, Chemnitz, Germany; W.L. Gore & Associates GmbH, Feldkirchen-Westerham, Germany; Chemnitz University of Technology, Institute of Lightweight Structures and Sports Engineering, Chemnitz, Germany; Chemnitz University of Technology, Department of Human Locomotion, Chemnitz, Germany

Consistency of subjective comfort ratings of running footwear

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