Evaluation of a rehabilitative pedorthic: plantar pressure alterations with scaphoid pad application

Scaphoid or longitudinal arch pads are frequently prescribed pedorthics for foot and ankle rehabilitation. These pedorthics are reported to be effective in mechanically supporting the medial longitudinal arch while reducing plantar and medial soft tissue strain. The objective of this study was to measure alterations in ambulatory plantar pressure metrics in a group of adults secondary to scaphoid pad application. The biomechanical rationale of this study was that the geometry of foot contact would be altered secondary to foot inversion. Ten adult male subjects with biomechanically normal feet were evaluated during multiple trials. A Holter type microprocessor-based portable in-shoe plantar pressure data acquisition system was used to record the dynamic data. Pressures were recorded from eight discrete plantar locations at the hindfoot, midfoot, and forefoot regions of the insole. Statistically significant (p < or = 0.05) increases in peak pressures were seen laterally with scaphoid pad application, while significant decreases in peak pressures with pad usage occurred at the hallux and the calcaneal region of the foot. At the medial longitudinal arch, peak pressures increased from near 0 to 115.3 kPa, contact durations increased from near 0 to 438 ms, and pressure-time integrals increased from near 0 to 33.4 kPa.s.