The influence of two different types of foot orthoses on first metatarsophalangeal joint kinematics during gait in a single subject

Objective: To quantify the effect of two distinct foot orthotic designs oil in vivo multisegment loot and leg motion, in particular, the first metatarsal and first metatarsophalangeal (MTP) joint during gait. Methods: A 23-year-old man had an excessively pronated foot structure as measured during it clinical orthopedic examination. The Optotrak Motion Analysis System was used to collect three-dimensional position and orientation data from four modeled rigid body segments (hallux, first metatarsal, calcancus, and tibia) during the stance phase of walking. The subject walked at a self-selected comfortable walking speed, and a minimum of five trials were collected under three different test conditions: no orthosis, semirigid orthosis with a varus post. and a semirigid orthosis with a varus post and a large medial flange. Data were normalized to the stance period, and descriptive suitistics were calculated for dependent variables. Results: Both orthotic interventions equally modifed first MTP joint motion when compared with the no orthotic condition. First MTP joint dorsiflexion was decreased (> 2 SD) with the orthosis during terminal stance phase, This decrease was associated with a concomitant increase in first metatarsal plantar flexion, Conclusion: A custom-made semirigid orthosis posted medially and made from it neutral position off weight-bearing plaster cast can alter motion in the forefoot during the propulsive period by increasing first metatarsal plantar flexion and decreasing excessive first MTP joint dorsiflexion.