Analysis of Torque and Stiffness Parameters in Different Cleat Models: Identification of Key Characteristics Using Regression Models

This study investigated the relationship between the physical characteristics of soccer cleats and their rotational resistance, aiming to identify the factors that influence maximum torque, stiffness, and the work required for rotation. Fifty-eight cleat models were analyzed, covering different classifications (FirmGround, HardGround, SoftGround, Turf). Tests were conducted in a controlled laboratory setting, utilizing X-ray fluorescence spectroscopy for material analysis, and a rigidimeter for longitudinal stiffness, and a 3D scanner for stud characterization. Rotational resistance was measured with a specific device that simulated the axial load applied to the foot and allowed for the determination of torque values. The results of the ANOVA indicated that cleat classification significantly influenced maximum torque, with SG cleats showing higher values and TF cleats showing lower values. However, stud design did not show a significant effect on torque. Multiple linear regression revealed that stud diameter, stiffness, and material type were significant predictors of maximum torque. Stratified analysis by stud type indicated that for circular cleats, material and stud diameter were the primary determinants of torque, while for pyramid-shaped cleats, the total number of studs had the greatest impact. Regarding stiffness, the overall model explained 41.2% of the variability, with material and stud contact area being the main predictors. Stratification by design revealed that circular cleats had higher stiffness when classified as HG. It is concluded that cleat classification, material type, and stud diameter are determining factors for maximum torque and stiffness, suggesting that these factors should be considered in the development of sports footwear.