Before Parkinson’s disease changed his life, Larry Jennings loved to sing, dance and play his guitar.

A decade after his diagnosis, the 73-year-old Oklahoma man is once again able to dance with his wife, thanks to the therapeutic power of music.  

Jennings’ remarkable improvement was captured on video that has gone viral since his physical therapist Anicea Gunlock shared it on Facebook. 

The video, posted earlier this month, at first shows Jennings struggling to walk around his home in Hartshorne, Okla., even with the help of a walker.

But when Gunlock started playing music on her cellphone, Jennings’ stride immediately improved. Within a couple of minutes, Jennings was able to let go of his walker and even lead Gunlock in a dance.

“I’d never seen anything like it,” Gunlock told CTVNews.ca in a phone interview Thursday.

Gunlock explained how, after her very first session with Jennings yielded no real improvements in his gait, she went home and started researching therapies for Parkinson’s disease, a neurodegenerative disorder that can severely limit a patient’s movements.

She came across a study that used music to help patients improve their gait and decided to try it out with Jennings.  Gunlock said she spent a considerable amount of time finding the right song – nothing too fast or too slow.  She eventually settled on “Good Ole Boys Like Me,” a 1979 country song by Don Williams.

“When I went back a couple of days later to do it with Larry, it was just astounding,” Gunlock said.  “Literally, it was instantaneous results.”

At one point in the video, Jennings is also seen singing along to “Good Ole Boys.” Since Jan. 5, the video has garnered more than nine million views.

“I’m really happy that it has been seen by so many people,” Jennings’ wife Kathy said, describing how everyone was “in tears” when her husband danced across the floor for the first time.

Now, “he can dance with whoever is around,” Kathy told CTVNews.ca. “We danced all over.”

She said caregivers often get discouraged as Parkinson’s disease continues to rob their loved ones of movement and speech.  But she’s always been hopeful that her husband’s condition would improve. 

“With his illness, you have to not give up,” she said. “We’re hoping that he’ll get even better.”

The power of music and dance

Music and dance have long been used to help Parkinson’s patients improve their movements and motor skills. A number of Canadian researchers have been involved in the global effort to better understand the therapeutic benefits of music for people like Jennings. 

“Right now, nobody has any idea what is going on in the brain to make this happen,” said Jessica Grahn, a professor at Western University in London, Ont., who has been researching the way music and rhythm are processed in the brains of people with movement disorders like Parkinson’s.

She said there seems to be “great variability” in how Parkinson’s disease patients respond to music. Some, like Jennings, show an instant response, while others show little to no improvement.

“One of the things we’re really interested in is…what is it that makes music effective for any given patient?” Grahn told CTVNews.ca. 

One of the working theories, she said, is that music enables the brain of a Parkinson’s patient to “bypass the faulty circuitry” caused by the disease. Many patients struggle with internally-generated movements -- trying to get up and walk across the room, for example-- only to realize that their brain is not receiving the signal. But reflexive movements, such as catching a ball thrown in their direction or dancing to music, seem to remain intact, Grahn said.

For Alice-Betty Rustin, who was diagnosed with Parkinson’s disease six years ago, music and dance programs have been more than just physical therapy.

“It’s also a great social (activity),” the 79-year-old Toronto-area resident said.  She has seen many other people with Parkinson’s benefit greatly from dance programs, including one offered at Canada’s National Ballet School.

Gunlock, the physical therapist in Oklahoma, said she decided to share her video online in hopes it would help other Parkinson’s patients and the therapists who work with them. 

“The response has been amazing,” she said.