In the third volume of the series "Theory of Medical Foot Treatment," the fundamentals of podological biomechanics are described. Possible causes of misaligned feet and their associated effects are explained. The methods of biomechanical foot examination are utilized, followed by the presentation of solutions to these problems. In practice, this knowledge can be applied in situations where pain conditions in the foot need to be addressed by podiatrists. The author emphasizes the necessity of interdisciplinary collaboration with other professional groups in his work.