Therapeutic effects of robotic rehabilitation on Neural and Muscular Abnormalities associated with the Spastic Ankle in Stroke Survivors

Spasticity is a common ailment following stroke, which can cause pain, contracture, abnormal limb posture and functional limitation. Early management of post-stroke spasticity is vital to reduce these complications, and improve function and help patients become independent. We propose a therapeutic program based on applying a series of vibrations to the ankle joints at specific ankle position as well as over the range of motion using a rehabilitation robotic system to reduce the neural and muscular abnormalities associated with spasticity. We provided a 30-minute perturbation training, 3 times a week for 10 sessions for 8 stroke survivor subjects. Ankle stiffness was calculated using the hysteresis curves. Other kinematic and kinetic parameters were also used to evaluate the mechanical abnormalities. We evaluated participants before starting the therapeutic program, immediately after first session of training and after 10 sessions of training. Our results showed that all subjects had substantial improvements in stiffness, max voluntary contraction, energy loss, passive range of motion, and voluntary movement after both short- and long-term therapeutic program. Surprisingly, for most of these measures the maximum improvement obtained at short-term training. Interestingly, these improvements became persistent over the long-term training. These findings suggest that vibration therapy can be considered as an effective rehabilitation intervention to reduce neuromuscular abnormalities associated with the spasticity in stroke.