In the Moment: Foot Orthoses
By Emily Delzell
Not all sham orthoses used in research settings provide the same mechanical effects or are perceived by study participants as equally credible, according to research epublished in May by the Journal of Foot and Ankle Research.
Investigators from La Trobe University in Melbourne, Australia, recruited 30 healthy adults and collected in-shoe plantar pressure data at the heel, midfoot, and forefoot at zero and four weeks under five conditions: shoe alone; customized polypropylene orthosis; contoured polyethylene sham orthosis; contoured ethylene vinyl acetate (EVA) sham orthosis; and flat EVA sham orthosis.
Results, similar at weeks zero and four, showed only the polyethylene sham orthosis had a nonsignificant effect on plantar pressures in all regions compared with the shoe alone. The other sham orthoses and the customized orthosis significantly reduced heel peak pressure. At the medial midfoot, all sham orthoses had the same effect as the shoe alone, while the customized orthosis had significantly greater peak pressure and maximum force at the medial and lateral midfoot, respectively.
Patients reported they perceived the customized orthosis as the most credible, while the polyethylene sham orthosis ranked last in credibility.
McCormick CJ, Bonannod DB, Landorf KB. The effect of customised and sham foot orthoses on plantar pressures. J Foot Ankle Res 2013;6(1):19.