Prediction of the height of the longitudinal arch of the foot based on plantographic indicators by means of artificial intelligence

The height of the longitudinal arch of the foot is an indicator reflecting the smallest distance between the lower edge of the articulation of the navicular and medial cuneiform bones and the support. It is used to detect the lowering of the longitudinal arch of the foot in orthopedic foot diseases. An urgent task is to predict the height of the longitudinal arch based on plantographic and podometric indicators using artificial intelligence (AI) technologies to reduce radiation exposure during diagnosis and the selection of orthopedic products. To predict the height of the longitudinal arch of the foot, an artificial intelligence model based on plantographic indicators was developed and evaluated. The study included 37 people who underwent computer plantography and radiography of their feet under load. Correlation analysis was used to select significant features, and a comparative analysis of AI models was conducted to determine the optimal machine learning algorithm. According to the results of the correlation analysis, a significant (p≤0.05) relationship with the height of the longitudinal arch was identified, and the following indicators were selected for further AI model training: the length of the foot from the most prominent point of the heel rounding to the center of the base of the second toe, the linear index of arch height, the coefficient of spreading of the forefoot, the maximum width of the forefoot, and the angle of deviation of the first toe. The best performance in predicting the height of the longitudinal arch of the foot was demonstrated by the Random Forest model with a mean square error (MSE) of 6.4359, a mean absolute error (MAE) of 2.1674, a coefficient of determination (R2) of 0.6932, a mean absolute percentage error (MAPE) of 7.6152 %, and a root mean square error (RMSE) of 2.5369. The developed Random Forest model demonstrates a high predictive accuracy for the height of the longitudinal arch of the foot based on plantographic and podometric indicators, justifying its use for diagnosis, selection, and design of orthopedic products for the correction and compensation of foot deformities.