The small pilot study, presented last month at the Paralyzed Veterans of America conference in Orlando, Fla., involved 10 wheelchair-dependent disabled veterans who had suffered spinal cord injuries an average 15 years earlier and who underwent scuba diving certification. Pre-dive tests checked the participants' muscle spasticity, motor control, sensitivity to light touch and pinpricks, plus depression, obsessive-compulsive disorder and post-traumatic stress disorder symptoms. Eight people completed the program and the study also included nine health controls who served as dive buddies.
Among the disabled vets, researchers found an average 15% drop in muscle spasticity, an average 10% increase in light touch sensitivity and an average 5% jump in sensitivity to pinprick. No one in the control group experienced any neurological changes.
PTSS treatment On the mental health side of things, post-traumatic stress disorder symptoms decreased an average 80%, all of which could not be attributed to the fact that the scuba training was done in a lovely Caribbean setting.
"What we saw in the water strongly suggests there is some scuba-facilitated restoration of neurological and psychological function in paraplegics," said study co-author Dr. Adam Kaplin in a news release. Kaplin is an assistant professor of psychiatry and behavioral services at the Johns Hopkins University School of Medicine in Baltimore.
Oxygen While cautioning that these are preliminary results and more study needs to be done, Kaplin has some theories on why water and weightlessness promote positive effects in people with spinal cord injuries. Water may provide buoyant resistance training they can't find on land, and when in the water, breathing isn't hindered by sitting in a chair. The participants may have also benefited from tissues being extra oxygenated from pressurised air, possibly causing improvements in muscle tone and sensitivity.
"There's a signal," said Kaplin of the results, "but only by repeating these results and showing significant improvements can we establish that. It's too early to know for sure."
Recovered feeling The idea for the experiment came from Cody Unser, founder of the Cody Unser First Step Foundation, a New Mexico-based nonprofit raising money and awareness for those with spinal cord-related paralysis. At the age of 12 Unser contracted transverse myelitis, an inflammation of the spinal cord that can cause muscle weakness or paralysis as well as pain or sensory issues. Unser, who is paralysed from the chest down, has been treated at Johns Hopkins and told Kaplin that she and others in wheelchairs recovered some feeling in their legs after scuba diving.