Static measure of foot loading

Static and dynamic loading of the foot are important characteristics for understanding human walking in both health and disease. The goal of this investigation was to determine whether an objective measure of normal midstance loading of the foot could reliably be recorded using readily available disposable qualitative recording devices. Ten randomly selected normal volunteers were trained to step on Harris mat and Pressure Stat recording devices during normal walking. Each of the recordings was divided into 5 weight-bearing regions by 2 separate examiners. After outlining each foot, the recordings were digitized and compared. Interobserver reliability ranged from 0.81 to 0.96 for the Harris mat technique and 0.94 to 0.97 for the Pressure Stat technique. Data from a linear regression plot indicate high precision of calculations of the foot masks between the 2 examiners based on an R(2) value of 0.966 using the Pressure Stat method. These data plus a linear regression plot suggest that both qualitative recording devices, when digitized using a standardized format, appear to obtain a reliable objective measure of midstance loading during normal gait. The Pressure Stat device may be slightly more reliable. It is planned to use this standardized experimental model to compare objectively patterns of midstance loading in patients with injury or disease that is capable of altering normal walking.