Boxing: Tired boxer easy prey for a big hit

Experts say that the power of a punch can be just one of several variables involved in a boxing knockout, writes KEVIN TAYLOR.

The punch that robbed Lennox Lewis of his crown looked powerful, but the heavyweight champion probably went down because he was pooped.

Lewis' fifth-round knockout by little-known American contender Hasim Rahman last Sunday shocked the boxing world and came after Australian female boxer Tricia Devellerez was knocked out in a bout in Christchurch.

She was in a comfortable condition in hospital yesterday after coming out of a drug-induced coma on Wednesday. Initially, her condition was critical. She does not want to talk.

The bouts have again focused attention on injuries from the ancient sport.

Few studies have been done on punching power and experts say many variables are involved in a knockout punch.

How tired a boxer is can be important. The BBC called Rahman's powerful right-hander that decked Lewis the "Punch of the Decade" - but it may not be.

One caustic commentator of the bout noted that Lewis looked tired in the second round. "He was puffing and panting like a horse on his way to the knacker's yard," said John Rawling, of BBC Sport.

And that may be the key to why Lewis went down.

Retired Auckland neurosurgeon Dr Philip Wrightson said damage to the brain was caused by the head swivelling with the force of a blow.

It did not necessarily relate to how strong the blow was.

Early in a bout boxers could withstand punches to the head, but when they tired a similar-strength blow could fell them.

Dr Wrightson, who wants boxing banned, said the effect of a head punch on the brain was like a bowl of jelly being tossed around. The jelly would break into small cracks. In a similar way, nerve fibres and blood vessels in the brain could be damaged from a strong blow.

An Auckland University biomechanics expert, Dr Bob Marshall, said the punch that felled Lewis spun his head to the right. It was the worst kind because it made the brain bounce back and forth in the skull.

Dr Wrightson said that blow would have killed a few thousand brain cells - but the danger for boxers was more from the many bouts they fought.

Long term, professional boxers often suffered dementia, he said. They had little self-restraint, boasted and often "talked nonsense."

A recent British study on punching measured small groups of elite, intermediate and novice boxers.

An elite boxer applied a mean force of 4800 newtons* using the rear hand, while an intermediate applied 3722 newtons and a novice 2381.

Auckland University physicist Dr Barry Brennan said a cricket ball hitting a batsman's head at 140 km/h - the speed reached by Pakistan express bowler Shoaib Akhtar - would impart about 1500 newtons force, a thumping cricket shot over the boundary 8400 newtons, and a 1500kg car hitting a tree at 100 km/h, 1 million newtons.

In an older punching study, 1960s British boxing legend Henry Cooper was tested by the Royal Air Force's Institute of Aviation Medicine.

His left fist's acceleration over 14cm was found to equal 60 times the force of gravity and travelled at 48 km/h, said Cooper's 1972 autobiography.

NZ Boxing Association president Dr John McKay, who is Devellerez's trainer, said amateur boxing's injury rate was low and overseas studies showed injuries were more prevalent in other sports.

"There are more punch-drunk soccer players."

Amateur boxing was safer than professional boxing because gloves were now designed to absorb more of the blow, and the rounds were shorter, he said. There were also better controls of matchups.

* One newton is the amount of force required to give a 1kg mass an acceleration of 1 m per second, every second the force is applied. Put another way, the force required to support the weight of 500 gm of butter is almost exactly five newtons.