Effects of foot characteristics and carbon fiber insoles on human sports performance

Abstract

Carbon fiber insoles (CFI), which are lightweight and stiff to reduce energy loss and help wearers perform better in sports, have recently been introduced. However, not everyone who wears CFI gains the performance improvement. This thesis aims to comprehensively analyze the effects of CFI on sports performance and to investigate the foot characteristics of wearers with improved sports performance using CFI. First, the effect of CFI on three major aspects of sports performance was evaluated through an experimental study with thirty Korean healthy young males. The results showed that compared to the baseline insole, CFI significantly improved sports performance in terms of power generation (by ~ 1.5 %) and agility (by ~1 %), but not speed. Second, the effects of foot characteristics on sports performance were examined by correlation analysis of experimental data from thirty-two Korean young healthy males. Several foot characteristics, along with height and weight, have been found to be associated with sports performance. Especially, foot width, ankle girth, calf girth, and gear ratio showed a positive correlation with power generation, and weight and arch height were negatively correlated with power generation. In addition, it was confirmed that the thicker calf circumference showed better agility. Third, a follow-up experiment was conducted to understand the specific foot characteristics of wearers with improved sports performance using CFI. Results showed that the arch height of wearers with improved sports performance using CFI was lower than wearers who did not improve sports performance using CFI. Also, the enhancement of sports performance from CFI was mainly associated with the arch height index. The findings of this study contribute to improving our understanding of the effects of foot characteristics and CFI and their interaction on sports performance, which may help develop design guidelines for athletic footwear and accessories to enhance sports performance.