A COMPARISON STUDY OF PLANTAR FOOT PRESSURE IN A STANDARDIZED SHOE, TOTAL CONTACT CAST, AND PREFABRICATED PNEUMATIC WALKING BRACE

Total contact casting is the current recommended treatment for Wagner Stage 1 and 2 neuropathic plantar ulcers. The rationale for this treat ment includes the equalization of plantar foot pressures and generaliz ed unweighting of the foot through a total contact fit at the calf. To tal contact casting requires meticulous technique and multiple cast ap plications to avoid complications before ulcer healing. An alternative to total contact casting is the use of a prefabricated brace designed to maintain a total contact fit. This study compares plantar foot pre ssure metrics in a standardized shoe (SS), total contact cast (TCC), a nd prefabricated pneumatic walking brace (PPWB). Five plantar foot sen sors (Interlink Electronics, Santa Barbara, CA) were placed at the fir st, third, and fifth metatarsal heads, fifth metatarsal base, and midp lantar heel of 10 healthy male subjects. Each subject walked at a cons tant speed over a distance of 280 meters in a SS, PPWB, and TCC. A cus tom-made portable microprocessor-based system, with demonstrated accur acy and reliability, was used to acquire the data. No significant diff erences in peak pressure or contact duration were found between the in itial and repeat SS trials (P > 0.05). Peak pressures were reduced in the PPWB as compared to the SS for all sensor locations (P < 0.05). Si milarly, peak pressures were reduced in the TCC compared to the SS for all sensor locations (P < 0.05) with the exception of the fifth metat arsal base (P = 0.45). Our results are summarized as follows: (1) the methods used in the current study were found to be reliable through a test-retest analysis; (2) the PPWB decreased peak plantar foot pressur es to an equal or greater degree than the TCC in all tested locations of the forefoot, midfoot, and hindfoot; (3) compared to a SS, contact durations were increased in both the TCC and PPWB for most sensor loca tions; and (4) the relationship of peak pressure over time, the pressu re-time integral, is lower in the brace compared to the shoe at the ma jority of sensor locations. The values are not significantly different between the cast and shoe. These findings suggest an unweighting of t he plantar foot and equalization of plantar foot pressures with both t he PPWB and TCC. Based on these findings, the PPWB may be useful in th e treatment of neuropathic plantar ulcerations of the foot.