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.

Inclusion Criteria:

• Symptoms located to the medial ankle or foot Pain on palpation to the posterior tibialis muscle tendon Positive single or double heel-rise test Foot flattening and ''too many toes" sign

Exclusion Criteria:

• Rigidity of those deformities Pain on palpation of the peroneal muscles Wearing any type of foot and/or ankle orthoses one month prior to the study onset History of corticosteroid injection in the tendon one month prior to the study onset Having a neurological disease or past history of surgery to the affected ankle