Evaluating the comfort of use of protective footwear: Validation of a method based on microclimate parameters and peripheral blood flow

• The paper presents validation for a method of evaluating the comfort of use of protective footwear.
• The characteristics of protective footwear hinder heat diffusion and moisture removal.
• Precise and repeatable plethysmographic results may facilitate the selection of protective footwear.
• Measurement permit effective and objective assessment of protective footwear in terms of user comfort.

The paper presents validation evidence for a method of evaluating the comfort of use of protective footwear based on microclimate parameters and peripheral blood flow in the lower limbs. A study involving impedance plethysmography showed that the inherent construction characteristics of protective footwear hinder heat diffusion and moisture removal, influencing peripheral blood flow in the lower limbs. The temperature and relative humidity inside the footwear, the weight of secreted sweat, and the weight of the support textiles (socks and liners) were measured and compared to the plethysmographic parameters. The components of measurement uncertainty were carefully determined for each studied parameter and uncertainty budgets were created. These results were subsequently used to identify measurement errors that could affect the quality and reliability of laboratory tests.