In this paper we explore the potential of prioritized inverse kinematics for motion capture and postural control. We have two goals in mind: reducing the number of sensors to improve the usability of such systems, and allowing interactions with the environment such as manipulating objects or managing collisions on the fly. To do so, we enforce some general constraints such as balance or others that we can infer from the intended movement structure. On one hand we may loose part of the expressiveness of the original movement but this is the price to pay to ensure more precise interactions with the environment