A coupling system to predict the core and skin temperatures of human wearing protective clothing in hot environments

Effects of personal protective clothing on firefighters' gait analyzed using 3D motion capture system

OBJECTIVES

The effects of personal protective clothing (PPC) on firefighters' gait were investigated to develop high-performance PPC.

METHODS

Thirteen participants participated in human trials with three types of PPC (firefighter protective clothing (FPC); semi-enclosed chemical protective clothing (CPC_semi); full-enclosed chemical protective clothing (CPC_full)) and T-shirt (CON). A 3D motion capture system was used to obtain gait parameters (step length, step width, stride frequency, gait speed, and toe-out angle) and the range of motion (ROM) of the joints (hip, knee, and ankle).

RESULTS

PPCs produced an increase in step width (23.4%, p > 0.05), but the gait speed (9.1%) and stride frequency (6.4%) decreased compared with the CON results. ROM is affected by the PPC type and joint. FPC and CPC_semi had no significant effect in terms of the ROM of the hip and knee besides the landing angle of the knee. However, CPC_full had a significant effect on the maximum extension angle of the hip and maximum flexion angle of the knee, which reached up to 27.2%.

CONCLUSION

The ROM of the firefighter's lower limbs were limited by PPC. This study offers insights into next-generation PPC design and development, as well as guidelines for training and firefighting.

Heat strain in chemical protective clothing in hot-humid environment: Effects of clothing thermal properties

Heat strain experienced by individuals wearing chemical protective clothing (CPC) is severe and dangerous especially in hot-humid environment. The development of material science and interdisciplinary studies including ergonomics, physiology and heat transfer is urgently required for the reduction of heat strain. The aim of this paper was to study the relationship among clothing thermal properties, physiological responses and environmental conditions. Three kinds of CPC were selected. Eight participants wore CPC and walked (4 km/h, two slopes with 5% and 10%) on a treadmill in an environment with (35±0.5) °C and RH of (60±5)%. Core temperature, mean skin temperature, heart rate, heat storage and tolerance time were recorded and analyzed. Physiological responses were significantly affected by the clothing thermal properties and activity intensity in hot-humid environment. The obtained results can help further development of heat strain model. New materials with lower evaporative resistance and less weight are necessary to release the heat strain in hot-humid environments.