skipping on uneven ground

It is known that humans intentionally choose skipping in special situations (e.g. when descending stairs, reduced gravity). Although those situations involve uneven locomotion, the dynamics of human skipping on uneven terrain has not yet been addressed. To find the reasons that may motivate this choice, we combined experimental data on humans with numerical simulations. Parameters for modeling were obtained from nine subjects skipping across a single drop in ground level. To model and describe the dynamics of skipping, we used a bipedal spring loaded inverted pendulum. We found that regardless of the leg that steps into the perturbation, leg adjustments in humans occur mostly or only on the trailing leg (landing first after flight phase). When transferring the identified strategies to the numerical model, the capacity of the model to cope with sudden-drop perturbations increased. Thus, simplified control, stability, and robustness might be key reasons to adopt skipping.