Shoe microclimate: An objective characterisation and subjective evaluation

Abstract

Shoe microclimate (temperature and humidity) has been suggested to contribute to perceptions of foot thermal comfort. However, limited data is available for perceptual responses in relation to shoe microclimate development both over time and within different areas of the shoe. This study evaluates perceptions of foot thermal comfort for two running shoes different in terms of air permeability in relation to temporal and spatial characteristics of shoe microclimate. The temporal characteristics of shoe microclimate development were similar for both shoes assessed. However, higher temperatures and humidity were observed for the less permeable shoe. Changes to shoe microclimate over time and differences between shoes were perceivable by the users.This study provides the most detailed assessment of shoe microclimate in relation to foot thermal comfort to date, providing relevant information for footwear design and evaluation. physical activity where the feet are enclosed in shoes for extended periods of times i.e. marathon runners (Auger et al. 1993). Intermediate levels of moisture have also been shown to increase coefficients of friction which have been found to influence the probability of blister formation (Sulzberger et al. 1966). Changes to the shoe microclimate therefore encourage the growth of microorganisms which can lead to odour development and to poor foot health. Knowledge regarding the subjective evaluation of shoe microclimate is limited, with little published information available. Although subjective perception of foot may not always coincide with measured foot (Barkley et al. 2011), local discomfort has been attributed to elevations in temperature rather than elevations in the moisture content both within hiking boots (Arezes et al. 2013) and within sock and boot liner materials worn within protective footwear (Irzmanska et al. 2013). The influence moisture has on foot comfort therefore requires further investigation as it is unknown whether changes in temperature and/or humidity help an individual in determining perceptions of thermal comfort. Despite the impact shoe microclimate has on foot health and foot thermal comfort, to our knowledge no quantitative shoe microclimate data is available over time, within different areas of the shoe or in relation to perceptual responses specifically for sports related footwear. With exercise, metabolic heat generation and sweat rates are high and so balancing the amount of heat supplied to or generated by the feet with heat loss becomes crucial. Currently, only changes to foot during running have been reported (Barkley et al. 2011; Shimazaki and Murata 2015; Shimazaki et al. 2015). During a 30 minute running bout at 12 km hr -1 temperature elevations from rest of 8.2°C were observed at the heel and 4.8°C at the neck of the big toe, foot regions associated with high contact loads and pressure during running (Shimazaki and Murata 2015). Increased ventilation within running shoes has also been shown to produce a cooling effect, reducing foot elevations, particula...

PCQ: Preferred Comfort Questionnaires for product design

“…Besides the selected 15 candidate questionnaires, participants also recommended other questionnaires which might be useful for comfort research. They are: 1) Shoe microclimate evaluation questionnaire [ 15 ]; 2) Situation awareness global assessment technique (SAGAT) [ 16 ]; 3) Methodologies for subjective evaluations of indoor environment in ISO 15251 [ 17 ]; 4) The scale used in ESI virtual seat solutions (PAM comfort) [ 18 ]; 5) the Kano model [ 19 ] and 6) Multifactorial assessment of comfort of clothing [ 20 ]. It is noted that whilst these questionnaires may be very useful for their targeted applications, they are difficult to apply outside of their application area focus.…”

Are running socks beneficial for comfort? The role of the sock and sock fiber type on shoe microclimate and subjective evaluations

“…The protocol employed has previously been used to objectively characterize shoe microclimate and perceptual responses for permeable and impermeable running shoes. 5…”

“…Tactile interactions which occur when materials come into contact with the human body are important in the perception of wetness when wearing apparel 26,27 and footwear. 5,28 Our previous experimental work 28 has shown that the perception of wetness and comfort at the foot is not dominated by regions of high sweat production but rather by tactile cues caused by foot movement in the shoe. Areas of low sweat production (toes and heel) were perceived as being wetter, stickier and more uncomfortable than the dorsal and plantar foot regions (areas of high sweat production) due to the expected higher contact loads and propulsion actions experienced and required at these regions during running.…”

“…Practically, asking participants to rate thermal sensation in relation to three temperatures (wide in range) reduces the ability to discriminate between sock conditions. At rest in thermo-neutral conditions, mean foot T sk typically ranges between 27 and 28 C, 5 and with exercise it could have been expected that all participants would have rated their sensations in line with the 35 C stimuli. It is therefore surprising that Bertaux et al 7 observed any differences in thermal sensation between sock conditions.…”

“…7 A recent characterization of the shoe microclimate (temperature and humidity within the air layer between the sock and the shoe) has been shown to differ between shoes of different permeabilities (while wearing identical socks), with these differences being perceivable by the wearer, influencing comfort. 5 The assessment of shoe microclimate, in addition to the assessment of foot T sk would therefore provide thorough insight into the thermo-physiological impact of the sock and factors affecting foot thermal comfort. Moreover, although the sock is recognized to be an important component within the foot-shoe system, the thermo-physiological and perceptual impact of not wearing a sock has not be investigated.…”