Golf pro Gary McCord insists that negative thoughts leaping across the synapses of the brain are ultimately destructive of a golfer's ability to take care of himself. The brain, McCord says, turns to a liquid. He can hear it sloshing about, like water in a bucket. He plays better in cold weather when the brain becomes an ice cube.

You don't have to be Dr. Joyce Brothers to know this is big medical news. So someone asked, "Is brain liquification a major problem on the golf tour?" And McCord said it sure was, adding that he sometimes wears earplugs so as not to lose any thought processes by drippage when he leans down to tee up a ball.

"Not many people in the public realize how dangerous golf is," McCord added.

If not, this week's PGA championship will tell them.

Bob Murphy, the leader by a stroke, has a thumb that recently was wrenched.

Larry Nelson has a bad back.

Dan Pohl's shoulder nags from above even as his left arch barks from below.

These are not metaphorical injuries, as McCord's is. These are documented by testimony of the players themselves. In every case, when questioned by the press about their recent slumps, these fellows described pain and suffering surely real and yet entirely comic in apposition to the injuries of other professional athletes.

I stand second to no one in admiration of the work done by professional golfers, for theirs is a discipline that requires remarkable coordination and unwavering concentration. It is true that even the slightest pain plays havoc with the delicate balance of mind and body necessary to take a hunk of iron and slap a teeny ball into a tiny hole in the middle of a pasture.

But, really. The way these guys sound, they're going to need ambalances to finish this tournament. The winner won't want the money, he'll want the Medal of Honor. Listen, please, to this conversation, overhead on the battlefield the first day.

"I'm having this terrible cramp," said J. C. Snead, limping down the 18th fairway.

"What?" said his wife, Sue.

"The toe right next to the little toe."

"Oh," Sue said. "Hey, you finally made a good swing back there."

"It burns like fire."

"Swing like that every time," she said.

"I'll go right to the driving range," J. C. said.

Bravely limping ahead on his cramping toe next to the little toe, Snead made a par at the 18th. No one knows what happens to the body to create a toe-next-to-the-little-toe cramp. But we researchers of the press ferreted out the causes of several other injuries.

Larry Nelson hurt his back lifting a shoe bag.

Laugh if you must, but remember these pros carry four or five pairs of golf shoes in a bag. With shoe trees. And shoestrings.

"I pulled a tendon or some ligaments or something," said Nelson. "You keep tearing the scar tissue loose. It has bothered me ever since I did it."

Did this happen last week?

"Two years ago."

John Matuszak could lift a shoe store and carry it around for two years.

Bob Murphy has trouble with his thumbs. In 1974 he broke his right thumb when he fell on a dark patio.

"This was late in the cocktailing hour," Murphy said.

He only wrenched his left thumb two weeks ago.

This was a woman getting on an elevator.

"I was carrying my golf bag in my right hand," Murphy said. "When she bumped into it, it turned the bag in my hand and strained the thumb."

Jack Youngblood made tackles within a broken leg, but Murphy withdrew from the Canadian Open with a strained thumb.

"It's the ulnar collateral ligament," Murphy said. "I had it taped up, and I was on medication. So I wouldn't have done any good up there, anyway."

As a kid, Murphy was a middle linebacker until he tore up his shoulder. Because a doctor in 1960 said the surgery was too risky, Murphy gave up baseball, too.When someone asked why he doesn't have the shoulder repaired now, Murphy said there is no need.

"I don't play active sports," he said, very seriously. "I play some tennis, but I serve underhanded."

Golfers are profiles in courage. You never know when you'll pick up a million-pound shoe bag or get blitzed by a New York woman on an elevator. You many even wind up hitting tennis balls like your Aunt Alice.

These thoughts were traversing my synapses when Dan Pohl came to the press room to tell us of his 67. Someone said, "Dan, how's the shoulder now?"

Turns out Pohl hurt his shoulder last year. He hurt it in combat, hitting balls at a range, and if Dick Butkus didn't send him a sympathy card it's ony because Dick lost Dan's address.

"For a full year, it gave me problems," Pohl said. "It was one of those nagging things. Then a chiropractor told me everything has its origin in our base, our foundation."

Dan means his feet.

"He told me I had a fallen left arch that created an imbalance on my left side that would cause the strain to go to my left shoulder."

So Pohl says he now wears a lift in his shoe, and his shoulder doesn't hurt anymore.

As inspirational as these stories are, none is the equal of Ray Floyd's daring exploit at the Masters six of seven years ago. Raymond was forced to withdraw because his back locked up. He was brushing his teeth when it happened.