The relationship between the supination resistance test, lower limb biomechanics and the effects of foot orthoses on foot and ankle biomechanics in individuals with posterior tibialis tendon dysfunction during gait.

BACKGROUND

Posterior tibialis tendon dysfunction (PTTD) is a debilitating condition that leads to biomechanical changes, for which foot orthoses are often prescribed to attenuate. There is a need to improve the ability to predict these biomechanical alterations, determine the biomechanical effectiveness of foot orthoses, and anticipate their effects on individuals with PTTD during gait.

RESEARCH QUESTION: Is the supination resistance test (SRT) reliable, and capable of predicting foot and ankle biomechanics, as well as the biomechanical effects of foot orthoses in individuals with PTTD during gait?

METHODS

Twenty-one individuals with PTTD participated with supination resistance measured over two sessions. Midfoot and ankle angles, and moments, were analyzed during gait. SRT test-retest reliability was evaluated, and the biomechanical effects of foot orthoses were assessed using statistical parametric mapping. SRT correlations with foot and ankle biomechanics and foot orthoses effects were examined.

RESULTS

The SRT demonstrated excellent intrarater reliability. Positive correlations were noted between the SRT and midfoot sagittal and frontal angles, while a negative correlation was observed with ankle sagittal and frontal angles. In the foot orthoses condition, midfoot dorsiflexion, external rotation, ankle eversion angles, and inversion moments were reduced. A negative correlation was identified between SRT and foot orthoses effects on the ankle frontal angle.

SIGNIFICANCE: The SRT is useful for predicting foot and ankle biomechanics, as well as the effects of foot orthoses on ankle frontal angles during gait in individuals with PTTD. These findings emphasize the clinical and research relevance of assessing supination resistance in PTTD management.