Biomechanical Effects of Three Types of Foot Orthoses in Individuals With Posterior Tibialis Tendon Dysfunction

Background : Posterior tibialis tendon dysfunction (PTTD) is characterized by a loss of function of the muscle caused by the degeneration of the tendon leading to a flattening of the arch. FOs can be used as a treatment option, but their biomechanical effects are not yet fully understood. The aim of this study was to investigate the effects of three different types of foot orthoses (FOs) on gait biomechanics in individuals suffering from PTTD. Methods : Fourteen individuals were recruited with painful stage 1 or 2 PTTD based on the Johnson and Strom's classification. Quantitative gait analysis of the affected limb was performed in four conditions: shoed condition (Shoe), prefabricated FOs condition (PFO), neutral custom FOs condition (CFO) and five degrees varus (medial wedge) with a 4 mm medial heel skive custom FOs condition (CVFO). A curve analysis, using 1D statistical parametric mapping (SMP), was used to assess differences in lower limb joint motion, joint moments and muscle activity over the stance phase of gait across conditions.