A suite of objective biomechanical measurement tools for personal load carriage system assessment

Abstract

For application to military and civilian needs, Defence Research and Development Canada—Toronto contracted Queen's University, Kingston to develop a suite of biomechanical assessment and analytical tools to supplement human-based load carriage system assessment methods. This suite of tools permitted efficient objective evaluation of biomechanical aspects of load-bearing webbing, vests, packs and their components, and therefore contributed to early system assessment and a rapid iterative design process. This paper is a summary of five assessment and analytical tools. A dynamic load carriage simulator was developed to simulate cadence of walking, jogging and running. The simulator comprised a computer-controlled pneumatic platform that oscillated anthropometrically weighted mannequins of varying dimensions from which measures of skin contact pressure, hip reaction forces and moments and relative pack-person displacements were taken. A stiffness tester for range of motion provided force-displacement data on pack suspension systems. A biomechanical model was used to determine forces and moments on the shoulders and hips, and validated using a static load distribution mannequin. Subjective perceptual rating systems were used gather soldier feedback during a standardized mobility circuit. Objective outcome measures were validated by means of other objective measures (e.g., Optotrak®, video, Instron®, etc.) and then compared to subjective ratings. This approach led to development of objective performance criteria for load carriage systems and to improvements in load carriage designs that could be used both in the military and in general.

Keywords:

• Backpacks
• Biomechanical assessment
• Dynamic load carriage simulator
• Load carriage system
• Mobility circuit
• Range of motion stiffness tester
• Static load distribution mannequin

Acknowledgements

The work described in this paper was funded by the Department of National Defence for the Defence and Civil Institute for Environmental Medicine (currently called Research and Development Canada—Toronto). Special acknowledgement goes to Jon Doan, Steven MacNeil, Alan Rigby, Emily Stevenson and Julie Kelly and, most importantly, the soldiers who volunteered as participants.