title: [Influence of carbon fiber foot orthoses on plantar pressure distribution in cycling].
abstract: BACKGROUND
  Several equipment interventions like optimizing seat position or optimizing shoe/insole/pedal interface are suggested to reduce overuse injury in cycling. Data analyzing clinical or biomechanical effects of those interventions is sparse. Foot orthoses out of carbon fiber are one possibility to alter the interface between foot and pedal. The aim of this study was therefore to analyze plantar pressure distribution in carbon fiber foot orthoses in comparison to standard insoles of commercially available cycling shoes.
  
  
  METHODS
  11 painfree triathletes (Age: 29±9, 1.77±0.04 m, 68±5 kg) were tested on a cycle ergometer at 60 and 90 rotations per minute (rpm) at workloads of 200 and 300 Watts. Subjects wore in randomized order a cycling shoe with its standard insole (control condition CO) or the shoe with carbon fiber foot orthoses (Condition CA). Mean peak pressure out of 30 movement cycles were extracted for the total foot and specific foot regions (rear, mid, fore foot (medial, central, lateral) and toe region). Three-factor ANOVAs (factor foot orthoses, rpm, workload) for repeated measures (α = 0.05) were used to analyze the main question of a foot orthoses effect on peak in-shoe plantar pressure.
  
  
  RESULTS
  Peak pressures in the total foot were in a range of 70-75 kPa for 200 Watts (W) (300 W: 85-110 kPa). The carbon fiber foot orthoses reduced peak pressures by -4,1% compared to the standard insole (p = 0,10). In the foot regions rear (-16,6 %, p < 0.001), mid (-20,0 %, p < 0.001) and fore foot (-5.9 %, p < 0.03) CA reduced peak pressure compared to CO. In the toe region, peak pressure was higher in CA (+16,2 %) compared to CO (p < 0,001). The lateral fore foot showed higher peak pressures in CA (+34 %) and CO (+59 %) compared to medial and central fore foot.
  
  
  CONCLUSIONS
  Carbon fiber can serve as a suitable material for foot orthoses manufacturing in cycling. Plantar pressures do not increase due to the stiffness of the carbon. Individual customization may have the potential to reduce peak pressure in certain foot areas.
authors: Hochschulambulanz der Universität Potsdam, Sportmedizin und Sportorthopädie, Universität Potsdam, Deutschland. heiner.baur@bfh.ch
authors: Heiner
authors: H
authors: Baur
authors: Jan
authors: J
authors: Hoffmann
authors: Anne
authors: A
authors: Reichmuth
authors: Steffen
authors: S
authors: Müller
authors: Frank
authors: F
authors: Mayer
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D002244:Carbon; D000077482:Carbon Fiber; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005528:Foot / Q000502:physiology*; D061826:Foot Orthoses; D006801:Humans; D008297:Male; D008422:Materials Testing; D011312:Pressure; D013314:Stress, Mechanical
chemical_list: D000077482:Carbon Fiber; D002244:Carbon