The HapticMaster is a high‑performance haptic robot widely used for upper‑limb rehabilitation, particularly with children. Its strength lies in delivering precise translational movements and force feedback, enabling therapists and researchers to design controlled, interactive rehabilitation tasks. However, the device has a fundamental limitation: it cannot directly control or sense wrist rotation. This constraint reduces the range of functional movements that can be trained, especially those involving pronation–supination, abduction–adduction, and flexion–extension—motions essential for natural hand use in daily activities.

To overcome this limitation, the project introduces a 3‑DOF arm/hand support mechanism that adds rotational capability to the HapticMaster. The mechanism is lightweight, adaptable to different hand sizes, and easily modifiable, making it suitable for pediatric use. Most importantly, it converts wrist rotations into pure translational movements that the HapticMaster can interpret, effectively extending the robot’s functional workspace without altering its core architecture. By enabling controlled wrist motion the 3‑DOF mechanism transforms the HapticMaster into a more complete rehabilitation platform, supporting richer motor tasks and more natural interaction patterns.