Can orthotic wedges change the lower-extremity and multi-segment foot kinematics during gait in people with plantar fasciitis?

Abstract

Background: Orthotic wedges with medial posting of the forefoot and rearfoot have been shown to be effective in controlling excessive foot pronation in people with plantar fasciitis (PF), however the best prescription remains unclear.
Research question: The aim of this study was to determine the biomechanical effects of two designs of orthotic wedges with the shoe on the hip, knee, rearfoot, and forefoot kinematics in individuals with PF.
Methods: Thirty-five participants with PF were recruited. They were asked to walk under three randomized conditions; shod, shod with orthotic wedges with foot assessment technique 1 (W1), and shod with orthotic wedges from a new assessment technique (W2). Biomechanical outcomes included lower limb and multi-segment foot kinematics in each subphase of the stance gait, including contact phase, midstance phase, and propulsive phase.
Results: Compared with shod, the W1 significantly increased shoe motion of rearfoot dorsiflexion, decreased shoe motions of peak forefoot dorsiflexion, and peak rearfoot eversion during the contact phase. In addition, W1 increased shoe motion of rearfoot inversion, decreased shoe motions of hallux dorsiflexion, and peak hallux dorsiflexion during the propulsive phase. For W2, the wedge significantly decreased peak knee internal rotation, decreased shoe motions of forefoot abduction, peak forefoot dorsiflexion, and peak rearfoot eversion during the contact phase. In addition, W2 increased rearfoot inversion, decreased hallux dorsiflexion, and decreased peak hallux dorsiflexion during the propulsive phase. When comparing W1 and W2, W1 showed greater shoe motion of rearfoot dorsiflexion during the contact phase.
Significance: These findings suggest that the use of forefoot varus wedges, and the combination of forefoot and rearfoot varus wedges, can change the lower limb kinematics, the shoe motions of multi-segment foot kinematics, and the relative length of the plantar fascia which would be associated with a reduction in pain and symptoms during walking.