In 1978 a 6'4" giant known throughout the slow southern town of Statesville, N.C, as "Big Jim" Thorneburg drove his golden custom-made Cadillac pickup truck to a fat farm in Durham and checked in. There to slim his 300-lb. mass to an eventual 240 lbs., he began to walk, and walk, and walk, I reckon I must have been walkin' six to 10 miles a day," he says—until finally he put through a call to the folks back at his family's knitting mill in Statesville and bellowed, "My feet are killin' me!"

And so, with orders to spin up a pair of special walking socks—incorporating padding in the heels and toes—Big Jim Thomeburg gave the family's then 26-year-old hosiery business the sport-specific kick it needed to take it to the forefront of the athletic sock industry.

Today Thor-Lo socks, sold across the nation and in 34 countries abroad to the tune of 8.4 million pairs and $23 million a year, are individually engineered for more than 20 activities—including running, skiing, cycling, even wading. For instance, in skiing socks, the densest part of the padding fabric is in the front shin of the sock, for the over-the-knee wading socks, padding is concentrated on the ball, the heel and the knee. "If you're standing up to your waist in water, duck hunting—versus, say, upland bird hunting," explains Thorneburg, "then obviously your shoe has changed, and so should your sock."

That kind of pedal punctiliousness has earned Big Jim and his Thor-Los a devout following, including baseball's Reggie Jackson, golfer Arnold Palmer and tennis's Boris Becker and Martina Navratilova. Navratilova, rumored to have "the prettiest feet on the circuit," became the brand's official spokesperson.

But Thorneburg's latest creation promises more than sporting comfort. The friction-reducing knit is designed to protect areas of the foot prone to ulcerations, a common problem among diabetics. Now being tested at clinics across the country, the socks are expected to reduce the risk of serious injury—even amputation—for the country's more than 12 million diabetics. Jim was all too familiar with the problems of those with the illness. His father, Lewis "Big Daddy" Thorneburg, was a 6'2", 360-lb. man mountain who suffered from many ailments, including diabetes, and died in 1974 at age 62.

It was Lewis who got the family's foot in the industry door as a worker in a local sock factory in the 1930s and '40s. Jim, an only child, was born in 1937 to Lewis and his wife, Mattie. "In those days," he begins, all drama and drawl, "Daddy'd work such long hours he'd come home exhausted, filthy dirty with black graphite grease all over him, an' Mama'd make him sleep on a bag of socks at the mill, an' I'd sleep there with him, on my own bag of socks."

In the early '50s, Lewis set up his own mill, and the decade brought, if not prosperity, then steady profit. At 21, after a hitch in the Navy, Jim married his high-school sweetheart, Pat, and joined the family business. And by the mid-'60s, thanks mostly to a patent for the first non-slip, non-roll-down golf sock for women, he'd taken the company to new levels of sock-cess. Says Jim: "Mama and Daddy were buying a new Cadillac every six months."

But wealth was no match for the pain that had for years plagued Lewis Thorneburg, who, in addition to diabetes, suffered from kidney stones and a weak heart. In 1974 he took his life, leaving Jim a piece of advice. "Son," Lewis told Jim, "a grizzly bear does whatever he wants to—live life like a grizzly bear."

And so Jim did, with a growl. After 20 years of marriage and five children (now ages 19 to 30), he was divorced from Pat and went into what he calls his "c-r-a-z-y Diamond Jim Brady" phase. "There are only two kinds of people in the Thorneburg family, that being saints and devils," he says. "Ain't nobody gray in our family." The self-made millionaire became a familiar sight in Las Vegas, where he blithely gambled more than $50,000 per trip. Holing himself up in seven rooms of the Statesville Ramada Inn, Thorneburg mostly just chased women and guzzled hooch. And then, abruptly, in 1980, he ended the craziness. "I had this enlightenment that sent me on a personal search," he says. "I just killed off ol' Diamond Jim."

Though Thorneburg's search for meaning became a five-year trek through the world's major—and a few minor—religions, it wasn't until Christmas 1986 that he found the final piece of the puzzle: his second wife, Missy. "She walked in with a green velvet dress on," Jim remembers their blind date, "and I absolutely fell in love with her. We were destined to be together." "When I heard who he was," counters Missy, whipping up some Cajun shrimp gumbo in the stately Confederate-gray house she shares with Jim, their son, Carter, 3, and her two children from a previous marriage, Ryan, 9, and Natalie, 6, "I said, 'He's too old, he has too many children and I'm not interested.' " The rest, as Missy, an interior designer, puts it, is history: "He kissed me on the back of my neck, and it sent this rush through me, and I went, 'Oh, shoot.' "

No longer footloose, Thorneburg has again turned his energies to sock development. His next project, he says, will be a sock for the 50-plus population that counteracts the natural breakdown of fatty pads on the ball and heel of the foot.

For the long run, he dreams of creating a North Carolina think tank devoted to curing the world's ills. More modestly, he might write a book on the importance of foot health. "It's not too big on the scale of world affairs," he says, "but one of my greatest accomplishments is that maybe I've caused people to look at socks in a totally different way—and, well, hey."

—Karen S. Schneider, Sue Carswell in Statesville