In one embodiment, a sensor unit includes an outer housing including a top plate and a base member that together define an interior space, the top plate being configured to directly receive and support the leg of the piece of furniture, a load cell provided within the interior space configured to measure forces imposed by the leg on the top plate, the load cell including a planar metal plate having a deformable element to which the top plate is mounted and a sensor element mounted to the planar metal plate at a location at which the deformable element extends from the remainder of the planar metal plate, and an internal platform provided within the interior space and associated with the base member that supports the planar metal plate of the load cell in a manner in which the deformable element of the planar metal plate is free to deform when a force is imposed by the leg on the top plate.