Members of Kennedy's inner circle had often witnessed the painful ritual that Kennedy endured in his private quarters before he ventured in public, when his valet would literally winch a steel-rodded canvas back brace around the president's torso, pulling heavy straps and tightening the thongs loop by loop as if it was a bizarre scene out of Gone With the Wind.

Once in it, the president was planted upright, trapped and almost bolted into a ramrod posture. Many would wonder how JFK could ever move in such a contraption. And yet move he did, and, besides his painkillers, his corset contributed to the youthful, high-shouldered military bearing that he presented glamorously to the world.

But this simple device imparted a fate almost Mephistophelean in its horror to the sequence of events in Dallas 41 years ago.

In researching my biography of governor John Connally of Texas 15 years ago, I was led to the critical importance of Kennedy's corset in the ghastly six seconds in November 1963 by a former Texas senator, the late Ralph Yarborough, who was in the motorcade that day.

Yarborough growled softly about that ``damned girdle,'' and this led me to the remarks of two doctors, Charles James Carrico and Malcolm Oliver Perry, buried in Volume 3 of the 26-volume set of testimony that attended the Warren Commission report.

In November 1963, Carrico was the 28-year-old resident in the emergency room of Parkland Hospital who first received the injured president in the trauma room; Perry came quickly to the emergency room to supervise the case - and then to pronounce the president dead a half-hour later.

Before the Warren Commission, Carrico told of removing Kennedy's back brace in the first seconds after his arrival. He described the device as made of coarse white fibre, with stays and buckles.

Apart from the never-ending controversy over how many bullets Lee Harvey Oswald actually fired from the Texas School Book Depository, most experts agree with the Warren Commission that Oswald's first bullet passed cleanly through Kennedy's lower neck, missing any bone, then entered Connally's back, streaking through the governor's body and lodging in his thigh. This was the first so-called magic bullet.

When Connally was hit, he pivoted in pain to his left, his lithe body in motion as it swivelled downward, ending up in the lap of his wife, Nellie.

But because of the corset, Kennedy's body did not act as a normal body would when the bullet passed through his throat. Held by his back brace, Kennedy remained upright, according to the Warren Commission, for five more seconds. This provided Oswald the chance to reload and shoot again at an almost stationary target.

The frames of the Zapruder film confirm this ramrod posture: Kennedy's head turns only slightly in those eternal seconds, and his upper body almost not at all, from frame 225 (when the first shot entered his neck) to the fatal frame of 313.

Without the corset, the force of the first bullet, travelling at a speed of 600 metres a second, would surely have driven the president's body forward, making him writhe in pain like Connally, and probably down in the seat of his car, beyond the view of Oswald's cross hairs for a second or third shot.

With no bones struck and the spinal cord intact, the president almost certainly would have survived the wound from the first bullet. Both Carrico and Perry testified to this likelihood (and apropos of the decades-long controversy, both testified that the small, round, clean wound in the front of Kennedy's neck was an exit wound rather than an entry wound).

To Perry, under the questioning of then-assistant counsel - now senator from Pennsylvania - Arlen Specter, the injury was ``tolerable''; the president would have recovered. Because the bullet had passed below the larynx, the wound would not even have impaired his speech later.

In the new focus on cortisone shots, codeine painkillers, barbiturates, stimulants such as Ritalin, and gamma globulin injections, the simple corset needs to be emphasised, tragically, in the context of those medical strategies Kennedy used to create the illusion of the vigorous leader.

LOS ANGELES TIMES

James Reston's forthcoming book is on the Spain of Christopher Columbus due to be published by Doubleday next year.