Heather Rendulic, 22, lost functional use of her left hand after suffering a series of strokes in 2012. A decade later, she can use a fork and knife again, owing to electrodes implanted in her neck.

In a lifetime, one in every four people will have a stroke, a condition in which the blood supply to a portion of the brain is cut off.

Individuals who survive are frequently left with long-term issues, such as muscle weakening or paralysis, with the prevalence of difficulties with arm and hand movements. These can have a significant influence on the persons affected, not least on their ability to do daily activities, such as eating, writing, or dressing.

Researchers revealed to have discovered a method to restore such motions by activating nerve cells in the spinal cord.

A stroke, according to researchers from the University of Pittsburgh and Carnegie Mellon University, can alter connections between brain and spinal cord regions that control arm and hand movements.

While some brain impulses are still transmitted, they are insufficient to activate the motor neurons that regulate muscular movement.

Read next: Correlation between blood type and early stroke discovered

The researchers describe how they attempted to restore such movement by stimulating the sensory neurons of the muscles, which connect directly with the motor neurons of the limb, in the journal Nature Medicine. As sensory neurons are excited, motor neurons receive additional excitement, making them more sensitive to brain impulses. To put it another way, by activating sensory neurons, impulses commanding muscles to move are increased.

Researchers implanted electrode arrays in Rendulic and another female stroke patient with chronic post-stroke upper-limb paralysis, as per the latest study.

The electrodes remained in place for 29 days, and the two individuals were subjected to four hours of testing per day, five days a week, for a total of four weeks, beginning four days after the electrodes were implanted.

The results show that when the stimulation was turned on, the subjects' arm and hand strength improved, as did their range of motion.

The stimulation also allowed the participants to execute tasks they would not have been able to do otherwise, such as opening a lock, drawing a spiral, eating with a fork, and completing reaching and moving tasks.

The study is not the first time that spinal cord stimulation has improved the lives of people who are paralyzed. Scientists have previously employed a similar strategy to help paraplegic patients walk again.

Read next: Avatar motion-capture technology proven applicable in disease research