Development of a Dynamic Biomechanical Model for Load Carriage: Phase 4, Part C4: User's Manual for the Standardized Protocol of Mapping Skin Contact Pressure Using the Standardized Load Distribution Mannequin; Contract rept

摘要

The Dynamic Biomechanical Model (DBM) requires input about pack geometry and the material property response of the load carriage suspension interface to resolve the forces acting on the body. Since there is extensive redundancy in applied forces (i.e., shoulder straps, load lifter straps, hip stabilizer straps and waist belt and skin contact pressure), it is not possible to describe the mechanical characteristics of pack components as combinations of linear and/or non linear springs and linear and/or non linear dampers unless a standardized protocol is used to determine the limit values that should be placed on specific straps in the model. The purpose of this report is to describe the common pack protocol on the Load Distribution Mannequin that will be followed when establishing these limit values for the DBM. The rationale for using the static Load Distribution Mannequin is that forces can be partitioned into upper and lower body forces, it is easier to control strap force inputs than with the Load Carriage Simulator and dynamic forces follow a similar profile to static measures expect that amplitudes and phase shifts are likely. (DBM model is calibrated for these conditions using the LC Simulator). This report describes the protocol for the baseline testing of backpacks on the Standardized Load Distribution Mannequin (SLDM). The protocol describes three different configurations: isolated shoulder, isolated waist belt and combined shoulder and waist belt.