Daily motor tasks are often redundant. Humans are known to adopt motor strategies which consist of a stereotypical selection of specific postures for a given task. Such natural strategies are also known to be perturbed. An exoskeleton, specifically designed to minimally perturb motor strategies, was used to study the effects of ergonomic factors and mechanical impedance on human motor strategies during redundant tasks. Special attention is devoted to wrist robots since the human wrist, together with the hand, is involved in most manipulation tasks. To comply with kinematic constraints,...