Plantar pressure sensors indicate women to have a significantly higher peak pressure on the hallux, toes, forefoot, and medial of the foot compared to men

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background:</jats:bold> <jats:bold><jats:underline>Sex</jats:underline></jats:bold>-related differences of plantar pressure distribution during activities should be thoroughly inspected as it can help establish treatment and prevention strategies for foot and ankle problems. In-shoe measurement systems are preferable without space and activity restrictions; however, previously reported systems are still heavy and bulky and induce unnatural movement. Therefore, a slim and light plantar pressure sensor was newly developed to detect the effect of <jats:bold><jats:underline>sex</jats:underline></jats:bold> difference on plantar pressure during standing and walking.<jats:bold>Methods:</jats:bold> One-hundred healthy adult volunteers (50 <jats:bold><jats:underline>women</jats:underline></jats:bold> and 50 <jats:bold><jats:underline>men</jats:underline></jats:bold>) were recruited. Ten plantar pressure sensors were implanted in a 1-mm thick insole, with a total weight of 29 g. Plantar pressure was recorded with 200 Hz during 3 seconds of standing and while walking 10 steps. The maximum loads during standing and walking were analyzed in each sensor, and the results were compared between different areas of the foot in the antero-posterior direction and the medio-lateral direction and between different time points. The movement of the center of pressure (COP) during walking was also evaluated. Results were compared between <jats:bold><jats:underline>sexes</jats:underline></jats:bold> by converting <jats:bold><jats:underline>body mass index (BMI)</jats:underline></jats:bold> to <jats:bold><jats:underline>22</jats:underline></jats:bold>.<jats:bold>Results:</jats:bold> The movement of COP was constant for both <jats:bold><jats:underline>sexes</jats:underline></jats:bold>. In all cases, the maximum load was observed on the <jats:bold><jats:underline>medial</jats:underline></jats:bold> of the foot. <jats:bold><jats:underline>Women</jats:underline></jats:bold> had a significantly higher peak pressure on the hallux, toes, forefoot, and <jats:bold><jats:underline>medial</jats:underline></jats:bold> of the foot compared to <jats:bold><jats:underline>men</jats:underline></jats:bold> while standing and walking (P &lt; .05).<jats:bold>Conclusions:</jats:bold> A newly introduced in-shoe plantar pressure sensor demonstrated a typical loading transition pattern of the foot. Furthermore, higher plantar pressure in the forefoot was detected in healthy <jats:bold><jats:underline>women</jats:underline></jats:bold> as compared to <jats:bold><jats:underline>men</jats:underline></jats:bold> during standing and walking activities.</jats:p>