Abstract: Various limb manipulation and evaluation devices are provided. The devices generally include three drives, namely a first drive configured to manipulate a first bone relative to a second bone in a first direction, a second drive configured to manipulate the first bone relative to the second bone in a second direction, a third drive configured to manipulate the first bone relative to the second bone in a second direction. The three directions are different relative to each other and in some embodiments represent three distinct axes. The devices are further configured such that at least one of the drives is mutually decoupled relative to at least one other drive, such that operation of the one drive does not affect the position or movement of the another drive. One or multiple of the drives may be decoupled. A corresponding method of operating such decoupled drives is also provided.