How reliable are pressure measurements with Tekscan sensors on the body surface of human subjects wearing load carriage systems?

Abstract

74% of adolescent backpack wearers suffer from neck or back pain. For other load carriage systems like protective vests and load bearing vests, overall musculoskeletal pain is significantly associated with carriage time. One factor, responsible for this kind of discomfort or pain, is the pressure at the body surface induced by the load carriage systems. Measurement of the pressure distribution at the interface between body and system is thus very important, but is currently still a technical challenge. Therefore, a subject study was conducted to determine the reliability of pressure distribution measurements on the skin of subjects wearing a protective vest and a load bearing vest. Measurements were taken with the subjects standing still and walking at 1.25 m/s. Foil sensors were placed in four different areas of the upper body. The intra-subject test-retest reliability of the analysed average and peak pressures was low, but an extensive evaluation of different data processing steps increased the reliability. A comparison of the results revealed that the choice of sensor location and data processing may well be the key to achieving acceptable reliability in future measurements. However, measuring the pressure distribution on the body surface of human subjects wearing load carriage systems remains a challenge. Nevertheless, all mechanical interactions between body and environment may involve critical body surface pressure. Therefore, future improvement of the measurement reliability is crucial for a wide variety of industrial, medical and daily routine applications.