A single gyrometer inside an instrumented running shoe allows mobile determination of gait cycle and pronation velocity during outdoor running

Excessive pronation is discussed to be a factor in the development of overuse injuries. Prolonged running has been claimed to increase pronation and pronation velocity (van Gheluwe and Madsen 1997, Derrick et al. 2002). However, this coherence is contradicted by findings of (Sterzing and Hennig 1999, Butler et al. 2007). A reason for this discrepancy might lie within the different methodical study designs used, because investigations of fatiguing effects on pronation were either bond to treadmill running, to pre-post-measurements, or were biased due to, although mobile, but unpractical goniometer measurements. A practical and reliable device for mobile pronation measurement is missing so far. A lot of research has been put into the development of devices for mobile kinematic measurements. Knee joint kinematics can be determined with high accuracy using gyrometers and accelerometers (Favre et al. 2008). For ankle kinematics during running, the use of accelerometer is highly problematic due to the massive crosstalk of the impact (Takeda et al. 2009). However, in a laboratory study we were able to demonstrate that the sole use of a gyrometer at the foot resulted in adequate pronation measurements in the frontal plane (Brauner et al. 2009). The purpose of this study was to investigate whether the use of a single gyrometer integrated directly inside the midsole of a running shoe is sufficient to detect the gait cycle and to determine maximum pronation velocity during regular outdoor running.