Intra–subject Variability of Impact Shock of Foot on the Ground during Walking and Running Activities

Abstract Aim: The intra–subject variability is evaluated by a deterministic acceleration model in the frequency content between walking and running activities. The usefulness of this research is to explore the dependence of peak acceleration of foot on different pedestrian’s velocity. Method: The mathematical model can be represented in time domain as a sum of Fourier harmonic components. The mathematical approach is applied to fit the accelerations of the foot, acquired during the impact shock of the human body on treadmill during walking and running activities at different speeds. Spectral analysis evaluates the frequency field of impact shock during walking and running activities. Results: The fitting of experimental data, by a mathematical approach, offers the analysis of the peak force of the foot on the ground, the dynamic acceleration factor (DAF) and the activity rate harmonics during walking and running activities. Conclusion: Marked differences in vertical accelerations are illustrated between walking and running activities. Recommendations could be deducted with regard to the dose of impacts that can be beneficial or detrimental to human health.