Date of Award
Spring 1995
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Biomedical Engineering
First Advisor
Harris, Gerald F.
Second Advisor
Wertsch, Jacqueline J.
Third Advisor
Silver-Thorn, Barbara
Abstract
Current foot pressure monitoring systems have short data capture intervals and permit recording of only a few consecutive steps with monitoring equipment frequently tethered to the subject by cable. These contemporary systems are unable to monitor in-shoe plantar pressures for more than a few minutes. Inherent gait variability requires that large numbers of steps be examined for reliable analysis and characterization. In order to fulfill demand criteria not available in current commercial systems, a Holter type, microprocessor based, portable, in-shoe, plantar pressure data acquisition system has been developed. The system is capable of recording continuous pressure data between the sole of the foot and the shoe for up to 16 hours (at a sampling rate of 20 Hz) during normal daily activities. The extended recording and processing capacity of the system allows quantitative analysis of cumulative plantar pressure and temporal gait data necessary for characterization of event-related alterations in plantar pressures. The system is fully portable, subjects carry it in a belt pack and ambulate freely without any disruption to their normal gait pattern. The system was applied clinically to collect pressure distribution data from several patient populations in order to quantitatively characterize the effects of treatment which have not been reported in the literature. Two studies of pedorthic use in adults were performed. The use of metatarsal and scaphoid pads were examined to determine and characterize the resulting plantar pressure redistribution. The evaluation of multi-step dynamics of pressure redistribution as a result of pad use is described. The system was also applied clinically in the evaluation of the planovalgus feet in children with cerebral palsy. A group of children with planovalgus foot deformity secondary to spastic cerebral palsy was evaluated preoperatively and following subtalar fusion for correction of the foot deformity. The pre- and postoperative distribution of plantar pressures and the alterations resulting from the surgical intervention are presented.