Humans excel at robust bipedal walking in complex natural environments. In each step, they adequately tune the interaction of biomechanical muscle dynamics and neuronal signals to be robust against uncertainties in ground conditions. However, it is still not fully understood how the nervous system resolves the musculoskeletal redundancy to solve the multi-objective control problem considering stability, robustness, and energy efficiency. In computer simulations, energy minimization has been shown to be a successful optimization target, reproducing natural walking with trajectory optimization or reflex-based control methods. However, these methods focus on particular motions at a time and the resulting controllers are limited when compensating for perturbations. In robotics, reinforcement learning~(RL) methods recently achieved highly stable (and efficient) locomotion on quadruped systems, but the generation of human-like walking with bipedal biomechanical models has required extensive use of expert data sets. This strong reliance on demonstrations often results in brittle policies and limits the application to new behaviors, especially considering the potential variety of movements for high-dimensional musculoskeletal models in 3D. Achieving natural locomotion with RL without sacrificing its incredible robustness might pave the way for a novel approach to studying human walking in complex natural environments. Videos: https://sites.google.com/view/naturalwalkingrl

Paris-based Wandercraft has announced that it's latest "Atalante" exoskeleton has been updated to give paraplegic and other patients a more natural gait during rehabilitation exercises. It also received a Medical Device Regulation (MDR) certificate in Europe, allowing patients and medical staff to use the device more widely. Finally, it's taken a step closer to personal exoskeletons with additional funding. The last time I saw Wandercraft's first-generation exoskeleton was over four years ago, which is ages in the field of robotics. However, I recently got a chance to see the latest model in use with paraplegic patients, and chat with them and the team behind Atalante.