The influence of reduced vision, reduced plantar sensation and simulated muscle weakness on plantar pressure distribution

Purpose: To examine the influence of reduced vision, reduced plantar sensation and muscle weakness on plantar pressure distribution. These factors were seperately simulated on disease-free cases.Material and Methods: The study group consisted of 20 healthy subjects (12M- 8F) ranged in age from 20 to 44 years. Subjects walked in five different conditions with their preferred walking speed. First was normal condition walking in normal gait pattern. Second was simulated muscle weakness walking by wearing waistcoat contains 40% of subject?s body weight. Third was reduced plantar sensation walking after 12 minutes ice immersion approach. Fourth was reduced vision by a pair of plane eyeglasess covered by black dots. Fifth walking condition was combination of iced feet, weight vest, and glasses. Plantar surface of the foot divided into ten different areas as two areas for hindfoot, two areas for midfoot, three areas for MTHs (1, 2, 3-4-5) and three areas for toes (1, 2, 3-4-5).Results: The peak pressure under the first, second and third metatarsal head were significantly increased under reduced plantar sensibility. The peak pressures increased significantly under the second and the third to fifth toes under blured vision (p?0.05). The peak pressure under the medial and lateral heel, second, and third to fifth toes were significantly increased under simulated muscle weakness. The peak pressure under medial, lateral midfoot, first, second, and third to fifth metatarsal heads were significantly increased under combined condition.Conclusion: Reduced plantar sensation simulation results in high pressure under all metatarsal heads, reduced vision simulation results in high pressure under the second and the third to fifth toes, muscle weakness simulation results in high pressure under heel. However, combined condition simulation increase the pressure under all metarsal heads, lateral and medial midfoot.Key words: Reduced plantar sensation, reduced vision, simulated muscle weakness, diabetic foot, plantar pressure