This paper presents a novel tool oriented to upper limb therapy and rehabilitation and a new wireless sensors technology application in rehabilitation robotics destined to post-stroke patients. Design was based on Inertial Measurement Units (IMUs) communicating trough of a ZigBee Network. This Body sensor network allows kinematics register and electrical activity quantification in muscles during rehabilitation therapy. The IMU implementation was based on a direction cosine matrix. The validation technique was represented by a kinematics measurement of tridimensional videography. Simultaneous registers, from cameras of kinematics videography and IMUs were compared on the gesture of reaching and grasping repetitions.