Dr. Norman Wood knows all about falling out of trees.
Fourteen years ago, a plunge from a tree left him with a broken back and a determination to keep others from suffering the way he did.
As an emergency-room physician, Wood knew that most accidents like his involve hunters falling from tree stands. He set about designing a harness able to prevent such falls. But the more he researched the subject, the more he discovered that harnesses sometimes do more harm than good.
"I wanted to create a full-body harness, because full-body harnesses give the best chance at survival," said Wood, who lives in Fort Ashby. "While doing my research, I learned about suspension trauma. What I found was that if you hang in a harness long enough, you will die."
Wood found that the U.S. Occupational Safety and Health Administration recommends immediate rescue of workers who fall and are suspended in full-body harnesses.
"According to OSHA, death can occur in 30 minutes or less," Wood said.
In a recent presentation to state Division of Natural Resources and West Virginia Hunter Education Association officials, Wood outlined why people sometimes die from hanging legs-down in a harness.
"With a full-body harness, the leg straps are the problem," he explained. "When a person is hanging in a harness, the leg straps constrict the thighs and put pressure on the big arteries that feed blood to the legs.
"The heart is a pump, and it has the power to push the blood past that constriction, but there is no pump in the legs to push the blood back to the heart. The blood pools in the legs, where it loses oxygen and becomes toxic."
Wood said that in only a few minutes, five to six pints of blood - 70 percent of the body's volume - can accumulate in a person's legs.
"When that happens, the heart can't get enough blood to feed the rest of the body. Blood pressure gets lower and lower. When it gets low enough, you pass out. After you pass out, you're dead within 5 to 10 minutes."
Tree stand manufacturers since 2009 have been required to include a suspension relief strap, a dangling strap with a loop the suspended hunter can stand in to relieve pressure in the groin area. Wood said the straps can definitely help, but often aren't enough to save victims' lives.
"Workers have survived up to two hours using a suspension relief strap, but it's not a cure-all," he explained. "Sometimes a hunter will hang in his harness for hours, or even overnight, before someone finds him."
While designing his harness, Wood came to the conclusion it needed a feature that would allow victims to quickly lower themselves to the ground. He developed a prototype and has had the Rescue One CDS (Controlled Descent System) harness and its variations on the market since fall 2009.
He insists, however, that his goal in preaching the perils of suspension trauma is not to market his harness.
"There are other harnesses on the market that allow hunters to lower themselves, and those get the job done too," he said. "As a physician, I want to get the word out to hunters that they can't just hang there in their harnesses and expect to survive. If they aren't in harnesses that allow them to descend, they need to do everything they possibly can to get back into their tree stand as quickly as possible.