Inter-subject variability and intra-subject variability in walking and running forces

Inter-subject variability and intra-subject variability during walking and running provide parameters that describe the walking and running forces. With regard to inter-subject variability, parameters, induced by different pedestrians, are pacing frequency, step length and magnitude of the walking and running forces. These parameters are analysed as a function of the pacing frequency. With regard to intra-subject variability, dynamic loading, caused by moving pedestrian, may be considered as a periodic force F(t). The force F(t) can be represented as a Fourier series. Typical vertical force patterns for different types of human activity (as a slow walk, normal walk, brist walk, fast walk, slow jog and running) are represented by deterministic force models. The Fourier decomposition provide dynamic load factor (DLF), activity rate, phase shift of each harmonic. DLFs are formulated as a function of step frequency as a function of person's velocity.