A wearable power assistive device for hand rehabilitation includes a hand brace having an external platform and an internal platform connected to and spaced inwardly from the external platform. Five finger assemblies are adjustably mounted on and extending from the distal end of the external platform. Each finger assembly includes a proximal follower assembly for a metacarpophalangeal joint. Five motors are used to actuate the five finger assemblies respectively. Each motor is mounted in close proximity to the external platform and has one end connected to the external platform and another end coupled to its proximal follower assembly by a ball joint in order to facilitate transfer of force and minimize mechanical stress on the other parts of the device.