A new approach to modelling the ground reaction force from a runner

Area of Science:

• Biomechanics
• Mechanical Engineering
• Sports Science

Background:

• Ground reaction forces (GRF) are crucial for understanding running dynamics.
• Existing lumped parameter models for GRF simulation have limitations in handling motion constraints.
• Mathematical models are needed to investigate factors influencing GRF, like body parameters and shoe sole design.

Purpose of the Study:

• To propose a novel modal modeling approach for simulating ground reaction forces (GRF).
• To overcome the motion constraints and complexity of existing lumped parameter models.
• To accurately predict GRF using vibration modes and a Zener model for viscoelasticity.

Main Methods:

• Decomposing GRF into contributions from system vibration modes.
• Employing a Zener model to represent the viscoelastic nature of the ground reaction.
• Validating the modal model against four experimental GRF datasets from existing literature.

Main Results:

• The modal modeling approach accurately captures GRF dynamics.
• At most three vibration modes (two oscillatory, one non-oscillatory) are sufficient for accurate GRF prediction.
• The model's effectiveness is independent of running speed and style.

Conclusions:

• The proposed modal modeling approach offers a simpler yet effective alternative to existing GRF simulation methods.
• This technique accurately models the complex dynamics of ground contact in running.
• The findings have implications for analyzing running biomechanics and designing athletic footwear.