When it comes to the pain in Jonny Wilkinson's neck and shoulder, kung fu expert Bruce Lee has a lot to answer for.
Reading the biography of the martial arts champion gave Wilkinson his manic devotion to aggressive defence, the consequences of which have seen him sit out most of the two months since he returned from his heroic drop-kicking exploits at the World Cup.
There is no braver sight on a rugby field than seeing Wilkinson felling opponents six inches taller and four stones heavier than his 5ft 10ins, 13st 10lbs frame with the crash tackles for which he has become almost as famed as his meticulous approach to goalkicking.
Recent evidence, however, suggests that the resulting 'stinger' collisions, affecting nerves in his spine which have given him pain in his arms and shoulders since he was a teenager, could curtail his phenomenal career.
In December a stress fracture in a vertebra was diagnosed, one Wilkinson almost certainly played with during the recent World Cup campaign, with the additional problem of a nerve trapped by the scar tissue caused by the fracture.
The fear is that if Wilkinson continues to make and take big hits he could risk neurological injury and arthritis in the future and even paralysis.
It is under such a shadow that Wilkinson has attempted to prepare for this season's RBS 6 Nations, unsure from one day to the next what his chances were of fulfilling any of the fixtures which begin with a Sunday date against Italy in Rome on February 15.
Even allowing for Charlie Hodgson's fragile knees, England possess capable fly-half substitutes, such as Paul Grayson, Alex King and Olly Barkley.
None are in the match-winning class of Wilkinson, who must surely now be persuaded to temper his all-action defensive style.
"Defence is very much a state of mind," says Wilkinson. "It's about controlled aggression and desire and I enjoy the confrontational side of the game."
Too often his burning desire tempts him to compete in rucks and mauls he has no right to enter as the world's best fly-half.
Wilkinson's job is to orchestrate the ebb and flow of the game from the number 10 position, not become an auxiliary wing forward just because he might happen to be nearest the action.
Stepping backwards, however, is not in Wilkinson's nature. The first inkling that the Newcastle star had a chronic problem was in April 2001 when a sore shoulder forced him from the field while playing for his club against London Irish.
Two brutal collisions against South Africa at Twickenham the following year almost certainly triggered the severity of the current injury.
First Wilkinson took an illegal hit from Jannes Labuschagne which saw the Springbok second-row sent off, then he was poleaxed late by iron man centre Butch James seconds after having let his pass go.
He left the field nursing his left arm and was not seen in action again for almost three months, though the same pain returned after one awkward tackle against Bath.
He failed to last 80 minutes against Italy in the Six Nations a month later, though he was back to guide England to a memorable Grand Slam which set them up for the heroics in Australia.
A tackle on Matt Giteau during the World Cup final, however, once again set the fears racing. A broken facet was later diagnosed but such was Wilkinson's desire to get back into action after the endless round of World Cup celebrating that he pressed to play against Northampton at the end of December when he lasted just 53 minutes, again leaving the field with neck and arm pains after making a heavy tackle on John Clarke.
"It has been part of my life for a long time," Wilkinson explained in his newspaper column. "I want to make sure it doesn't end my career early. The hits on Matt Giteau and on John Clarke were more than stingers. It's given me some distress down my right side. It's taking some time to get the strength back."
The admission was the first clue to the full extent of the physical pain - though Wilkinson's complex nature is most likely where the root of his the problem lies.
"I don't think I could live with the feeling of regret if I don't make the most of what I've got now," he said amid the World Cup euphoria.
"I've got many goals that I've ticked off and many goals still running. I want to improve as a player. I had games in the World Cup where we won and that takes precedence over anything, but deep down you know you could have done things a bit better.
"I want to be able to find a way of doing those things. I can't live with the feeling that I didn't give my best. If I try my best and it doesn't go right I can accept that. If my mind's somewhere else I'd never live that down."
The pursuit of perfection, especially on a dodgy shoulder, is the heaviest of burdens - one for which in part English rugby can blame the king of kung fu.