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The aim of this study was to evaluate the accuracy of the vertical force curve of a pressure plate (PP) using dynamic calibration with a force plate (FP) in six sound Warmblood horses. The animals were walked and trotted over a combined PP-FP system sampling at 250 Hz. Five valid measurements of each forelimb were collected. The recalibration factor (RF), the ratio between the calibrated and raw PP data, was evaluated in each timeframe throughout the stance phase. Following dynamic calibration, the vertical force curve of the PP demonstrated a characteristic biphasic pattern at the walk and typical spikes at the beginning and end of stance at the trot. Both at walk and trot, the RF was considerably higher and more variable in the first 5% of stance (i.e. the impact phase) and during the final 20% of stance (i.e. the breakover phase), whereas between these phases (i.e. in the support phase), the RF was lower and remained relatively constant. These findings were confirmed by plotting the RF as a function of the vertical force and the RF in the loading part of the vertical force curve was lower than in the unloading part of the curve. Without dynamic calibration with a FP, the accuracy of the PP appears suboptimal, especially at the impact and breakover phases. However, the accuracy of the PP was relatively high and constant during the support phase, and higher loading was not associated with increasing deviation. It is therefore essential to optimise PP calibration, as this may downsize systematic measuring errors. However, in a clinical setting, where a stand-alone PP is used to objectively quantify locomotor symmetry, these errors can be readily eliminated by evaluating left:right symmetry ratios.

REASONS FOR PERFORMING STUDY: Thus far, pressure-plate analysis has been limited to measurements on a hard surface, whereas equine athletes routinely perform on a deformable substrate. OBJECTIVES: To explore pressure-plate analysis on arena footing. STUDY DESIGN: Nonrandomised crossover study using noninvasive techniques. METHODS: Five sound, unshod ponies were walked and trotted over a pressure plate in 2 different conditions. In the first session, the plate was covered with only a 5 mm rubber mat, and in the second session, with an additional 50 mm layer of sand and synthetic fibres. Limb loading and timing variables (peak vertical force, vertical impulse, peak vertical pressure, hoof contact area and stance phase duration) were obtained. Toe-heel and mediolateral hoof balance of the vertical force were calculated throughout stance (126 Hz). RESULTS: Peak vertical force, vertical impulse, peak vertical pressure and stance phase duration were decreased on the soft substrate, while hoof contact area increased. At impact, there was more even load distribution between the toe and heel region on the soft vs. hard surface. At mid-stance, there was more loading of the toe region on the soft compared with the hard surface. At impact, there was more even load distribution between lateral and medial on the soft vs. hard surface at walk, but not at trot. CONCLUSIONS: Comparison of observed vs. expected impulse indicated that the main factor involved in the lower loading on the soft surface is the dampening effect of the soft substrate, although definitive conclusions require concurrent force-plate analysis. The pressure plate permitted quantitative evaluation of hoof balance of the vertical force on a deformable surface at the walk and trot and proved that there is more even load distribution on arena footing.

Logistik ist ein Arbeitsfeld mit Zukunft. In der Diskussion um teure Mitarbeiter und hohe Produktivität wird immer mehr klar, dass althergebrachte Produktions-, Handels- und Dienstleistungskonzepte nicht ausreichen, um Arbeitsplätze und Wohlstand zu sichern. Die Logistik beschäftigt sich in Wissenschaft und Praxis mit der Suche nach neuen Lösungen der Planung und Steuerung, der Optimierung und Umgestaltung ganzheitlicher Systeme. Dieser realen Vision fühlt sich die Gastvortragsreihe Logistik verpflichtet, die in diesem Jahr bereits zum zehnten Mal durchgeführt wird. In einem Forum werden hochrangige Vertreter aus Industrie, Dienstleistung, Handel und Verkehr, ihre Ideen und Konzepte in insgesamt neun Vorträgen einem breiten Publikum präsentieren. Ziel der Veranstaltung ist es, den Stellenwert der Logistik in der Region zu erhöhen. Im Anschluss an die Vorträge wird den interessierten Teilnehmern stets ein breiter Raum zur Diskussion und Fragerunde an den Referenten geboten. Die Teilnahme ist selbstverständlich kostenfrei, alle Interessierten sind herzlich eingeladen.