An interface system in an exoskeleton includes a base support, a strap assembly, and posterior strut. The posterior strut has a vertical member defining a lower end connecting to the base support, and an upper end connecting to first and second transverse members extending in opposed directions from the vertical member. The first and second transverse members connect to the strap assembly. The interface system is adapted to receive and support an assistive device adapted to augment a user's performance and mitigate repetitive strain injuries.