Story highlights Four men, paralyzed from the chest down, now can stand thanks to electrical stimulators implanted in their spines

This development is being hailed as a breakthrough in spinal cord injury research

Patients already are seeing other benefits, such as increased mobility and the ability to have sex again

(CNN) In what's being hailed as a breakthrough in spinal cord injury research, four men paralyzed from the chest down have risen from their wheelchairs on their own volition and effort.

"I can stand up for more than half an hour," said Dustin Shillcox, who was paralyzed in a car accident five years ago. "It's awesome. It's amazing. It's a hopeful feeling."

Shillcox and the other three men had electrical stimulators surgically implanted in their spines, and are working toward walking again someday. Their standing achievements were published Friday in the online journal PLOS ONE by Dr. Susan Harkema and her colleagues at the Kentucky Spinal Cord Injury Research Center at the University of Louisville.

The Christopher and Dana Reeve Foundation, which helped fund the study, has named the Kentucky research as its " Big Idea " and is raising $15 million to do the procedure in dozens more patients.

Already, more than 4,000 people have signed up to become research subjects.

Read More