John E. A. Bertram

This study shows that vertical ground reaction force morphology during walking reflects the imbalance between push-off and collision impulses, with a preferred balance at 1.2 m/s.

The paper develops a modified inverted pendulum model to show that human walking speed and step length are constrained by mechanical feasibility and work capacity, not just energy efficiency.

The paper shows that pre-emptive push-off optimizes walking economy, while delayed push-off during uneven walking incurs mechanical costs.

The paper investigates whether extending step length or stepping over perturbations is more energy-efficient during uneven walking, finding a velocity-dependent threshold for each strategy.

This study estimates preferred walking speeds by analyzing center of mass work, finding optimal push-off impulses that minimize energy dissipation across different terrains and demographics.

This study examines how speed and gravity affect the energetic cost of walking and running, finding that dissipative losses, not distinct energy-saving mechanisms, explain the differing responses.