Development of a Dynamic Biomechanical Model for Load Carriage: Phase 4, Part C2: Assessment of Pressure Measurement Systems on Curved Surfaces for the Dynamic Biomechanical Model of Human Load Carriage

Abstract : Soldiers experience pressure as a result of their personal load carriage system acting on the shoulder and back. As such, an experimental measurement tools must be able to accurately and repeatability measure pressures on these curved surfaces. The purpose of this study was to examine pressure measurement systems on curved surfaces resembling the shoulders and the hips. To accomplish this, a method developed by Hadcock (2002) that resolves normal force vectors into vertical and horizontal components was used to test the validity using two different pressure measurement technologies: the XSENSOR X36 model by XSENSOR Technology Corporation and the F Scan (F socket series) model by Tekscan Incorporated. The testing jigs used in this study were a cylindrical shape for the shoulder and an elliptical shape for the hips. Under ideal test conditions, results showed that the XSENSOR had a 2% accuracy error on the shoulder and 4% accuracy on the hip, which is notably better than the 72% accuracy error on the shoulder model and 53% accuracy error for the hip model found for the F Scan. The F Scan errors were due primarily to working at the low end of the sensor's range and bending the mylar around a 114 mm diameter cylinder that induces a preload on the sensels.