Design and analysis of a novel fall prevention device for lower limbs rehabilitation robot.

BACKGROUND: Most stroke survivors are suffering from physical motor impairments and confronting with the risk of falls, and well trunk stability is essential for balance during daily functional activities.

OBJECTIVES: Current fall prevention devices have various limits to the efficient recovery of balance function of the trunk. To provide hemiplegic patients after stroke with the retraining of trunk position sense and a safety environment, a novel fall prevention device is proposed.

METHODS: Firstly, the structure of the device is introduced and this work is a first effort towards restoring trunk balance function through retraining of trunk position sense. Secondly, the kinematic and static model of the device are developed. Lastly, kinematic and static analysis are carried out to study the motion characteristics, and a contrast experiment was derived to show the effectiveness of robot.

RESULTS: No obvious difference in balance ability between two groups prior treatment (P> 0.05). Fugl-Meyer assessment in all the cases were improved in different extent (P< 0.05). The robot group had significantly higher Fugl-Meyer scores after treatment than the control group (P< 0.05).

CONCLUSIONS: The results show that the fall prevention device has good kinematic dexterity within the prescribed workspace and markedly improves balance function.