The aim of this study is to put forward potential advantages of redundant haptic devices. The use of redundancy in haptic devices basically piovides a larger workspace without changing kinematics parameters such as joint variables, joint offsets, effective link lengths and twist angles. Besides an increase in the workspace, redundant manipulators allow appropriate posture selection for different purposes, such as singularity avoidance, obstacle avoidance, inertia minimization, power minimization. These purposes can be considered either together or separately in order to determine optimal posture. The study in this paper is focused on optimal posture control of a 7 DOF haptic device based on power minimization. The designed haptic device has 4 DOF for positioning stage and 3 DOF for orientation stage.