Three of its most prominent players are returning to serious competition after serious surgery, two more are hampered by shoulder and wrist problems, another is resisting a back operation and a flock of others literally are hanging upside down to avoid injury. And you thought golf was the one sport where no one got hurt.

"When you stop to think about it, the golf swing can be a pretty violent thing," said one of the hangers, Joe Inman. "Take what happened to me a while back. My wife just had a baby, so I had to fly from 10:30 p.m. to 4 a.m. to a tournament. I'd slept in air conditioning and had this crick in my neck.

"I wouldn't have much time to loosen up - and I could really have done something on the first tee that would have had me down for a month. Instead, I took a hot shower, hung for several minutes in my room and went out and shot 69. What I'm doing is trying to prevent problems, at least delay the inevitable. I was starting to get little muscle spasms. I could see the handwriting on the wall."

Inman is hanging, and so are Gene Little, Jerry McGee and Graham Marsh, twice a day mostly, and on contraptions that cost at least $500 and are reasonably simple to install on the bathroom doors of the motels they frequent.

"It's called Gravity Gym," said Inman, "and what you're actually doing is sitting upside down, stretching the back muscles, getting rid of all the tensions of the day. I'm gonna show it to Lee Trevino and Sam Snead this week. I know Lee won't be able to resist it."

And what of Snead, who probably hit at least 2 million shots in competition before his back began bothering him three years ago, at age 62? HOw did he last so long?

"That man," said Inman, "is the loosest athlete ever to play golf. Until recently, he could pick the ball out of the cup flatfooted. And he could kick his leg up and hit the top of an eight-foot door. There's been nobody like him."

At 65, Snead was sitting in the locker room the other day listening to a man give an impassioned pitch for acupuncture. In both of his U.S. Open rounds here, in heat that approached 90 degrees, he would not sit down during delays, possibly because he feared he could not get back up. He does not chew gum, he once said, because it irritates the small muscles around the eyes.

Snead has avoided back surgery; Trevino has not. Rod Curl is just getting his game back in order after a wrist operation; Jerry Pate, the defending Open champ, has been bothered by shoulder ailments most of the year; John Mahaffey, who lost the Open two years ago in a playoff and led the Open last year through the final 16 holes, has played in just two tournaments this year, winning $46,43.

Andy Bean had to skip the Sea Pines Heritage Classic this year because of a shoulder injury suffered when he tossed his golf ball into the lake off the 18th green when he wond at Doral. McGee kicked his putter in frustration once at Doral and was forced to cut out a portion of his right shoe to walk around the course.

Trevino, Bobby Nichols and Jerry Heard were struck by lightning two years ago during the second round of the Western Open. All were playing quite well at the time, Heard seemingly with a rich future and Nichols the first-round leader in the Masters that year and an exempt player his entire 16-year career. Only Trevino has played a lick since, and only after the back operation Heard is trying to avoid.

"I'm convinced that if Heard would hang three or four times a day, he'd be all right," said Inman. "But he sits around and eats all the time; he's gained 20 pounds and has to crawl to the bathroom. But you know Jerry."

One of the more delicate operations was performed on Archer, whose left hand was nearly powerless after a torn tendon in his wrist finally would tolerate no more abuse.

"I know exactly the day it happened," said Archer. "I was playing in New Zealand at the time. And it snapped. That was in '73. The doctors kept saying it would get better by itself. I finally had the operation in April of '75.

"I'd lost all feeling in my arm to the armpits. I was in a cast six weeks, and at age 35 that's an awful tough thing to recover from. I knew giving up the tour was a possibility, but I never considered it."

In 1974 and '75, Archer's total winnings were under $30,000, after earning more than $100,000 in four of the prior six years. Lst year, he went limping along at an $8,000 pace until the 42d tournament of the year, the Sahara Invitational. He won it.

At mid-year of '77, Archer has won $30,389 for 55th place on the money list. He made the cut at the Open, after tinkering with the grip on his putting stroke. He was beside himself with joy over two shots, on the par-5 16th hole.

"I had 210 yards to the front of the green," he said. "That's a four-iron shot on a 569-yard hole. Means I drove the thing almost 360 yards. From where I once was, that's something."