Biomechanics

About 10 years ago the running shoe market turned euphoric: Natural Running was the new trend,  at the same time it was the counterdraft of the previous running shoe concepts. But soon it showed that many runners were overwhelmed with the new shoes. But does this contradict the concept of the shoes? Martin Daumer, a convinced “minimalistic” runner, dealt with the topic on a scientific level.

P.W. Brand coined the statement “Pressure is the critical quantity that determines the harm done by the force” meaning that not the forces acting on the foot primarily cause an overload, but the pressure which is defined as the force acting on a certain area. Therefore, pressure distribution measurements indicate how the foot is loaded during ground contact and in which locations high, possibly even damaging pressure values may occur and cause pain. The measurements may provide an objective evaluation of the foot function under dynamic loading conditions. Therefore, plantar pressure distribution measurements have been established in the last years as clinically accepted procedures for the functional examination of foot problems caused by diseases, injuries or deformities. Furthermore, they have developed into a diversely used research tool for detailed examinations of foot biomechanics.

Background

Due to its positive effects on cardiorespiratory and muscular fitness and its accessibility, running is a common recreational sport with increasing popularity [1 – 3]. According to a survey conducted in 2014, 23.3% of the Swiss population (aged 15 to 74 years) runs at least once a week [4]. In the EU, the total number of runners can be estimated to be 50 million [5] and in the USA more than 40 million people run regularly [6]. Despite the health benefits of running, there is, however, a yearly incidence of 19.4% to 79.3% in runners suffering from a running-related injury [3, 7]. Overuse is an important cause of running injuries, whereas debates continue about the aetiological factors.

Plantar pressure measurements can be used to assess the loads to which the human body is subjected in normal walking or in sports. Measuring the distribution of force over the sole of the foot is useful as it provides detailed information specific to each region of contact. Especially in patients with diabetic foot syndrome these data are crucial for detecting areas with high loads and for the monitoring of intervention measures.