This study presents the measurement of the angular position and acceleration during the leg gait and the data fitting using Fourier series to parameterize the measurements obtained through accelerometers. The sensor reference is the gravity direction for the three axes that is converted into angular position and acceleration data. For this study, measurements were made in the femoral area of a human leg. The curves were obtained based on Fourier series, and though a homologation made to their harmonics, we obtained ordinary differential equations (ODEs) that parameterize these curves. The curves were approximated using six harmonics, resulting in six ODEs. The summed solutions of the ODEs represent the angular position or inclination of the leg during a walk step. The first and second derivative of the ODEs means the velocity and the acceleration of the leg movement. These types of tools are required in different research subjects such as health, entertainment, and engineering.