Virtual reality and physical therapy may prove helpful in improving motor skills in damaged limbs. Researchers from Israel's Tel Aviv University (TAU) examined healthy patients who used 3D virtual reality to improve movements in one hand by "training" it with the dominant hand.

"Patients suffering from hemiparesis—the weakness or paralysis of one of two paired limbs—undergo physical therapy, but this therapy is challenging, exhausting and usually has a fairly limited effect," said lead investigator Roy Mukamel of TAU's School of Psychological Sciences and Sagol School of Neuroscience, who conducted the research with a student, Ori Ossmy. "Our results suggest that training with a healthy hand through a virtual reality intervention provides a promising way to repair mobility and motor skills in an impaired limb."

In a study of 53 healthy participants who were sent into a virtual reality via a headset, users saw a mirror image of their hands where if they move their right hand their left virtual reality hand would move. Participants first completed a finger movement test with their right hand, moving the virtual left hand, then having motorized gloves automatically move the left hand while seeing the virtual right hand.

Results showed that while participants moved their finger on the right hand, while seeing the virtual left hand move, their actual left hand moved more efficiently after the exercise. The biggest improvement happened while participants were wearing the motorized glove.

"We effectively tricked the brain," said Mukamel. "Technologically, these experiments were a big challenge. We manipulated what people saw and combined it with the passive, mechanical movement of the hand to show that our left hand can learn even when it is not moving under voluntary control.  We need to show a way to obtain high-performance gains relative to other, more traditional types of therapies. If we can train one hand without voluntarily moving it and still show significant improvements in the motor skills of that hand, we've achieved the ideal."