How many punches can a guy take

At the same time, even an unarmed person can inflict an astonishing amount of damage with the proper training. So how much does it take to crack a bone? And how much mayhem can a person deal out? In an era when "extreme fighting" has become a popular phenomenon, scientists are testing the extremes that athletes at the peak of their game can reach in order to help the rest of us. Bone is extraordinarily strong — ounce for ounce, bone is stronger than steel, since a bar of steel of comparable size would weigh four or five times as much.

A cubic inch of bone can in principle bear a load of 19, lbs. Still, whether or not bone actually withstands such loads depends heavily on how quickly force is delivered. Taking a beating "When you perform CPR, you can give chest compressions and not break any ribs, but if you apply the same amount of force quickly instead of slowly, and you can end up having rib fractures," Bir explained.

When it comes to unleashing force quickly, Bir and her colleagues investigated boxers and found they could generate up to 5, newtons of force with a punch, more than that exerted down by a half-ton on Earth's surface. Liam Rockley, a year-old former bouncer, later pleaded guilty to manslaughter and was sentenced to three-and-a-half years in prison. While no official figures are available on one-punch deaths, the campaign group One Punch Can Kill has recorded more than 80 fatalities since Many of the cases have attracted media attention - in large part because it seems extraordinary that one punch can kill.

But Duncan Bew, a consultant in trauma and acute care at King's College Hospital, said this reflects a fundamental lack of understanding. Mr Bew said deaths from one punch tended to happen in one of three ways. Sometimes, as in Robert's case, the blow itself will cause fatal damage to the brain.

Alternatively, it could cause a physiological response where people stop breathing and the brain is starved of oxygen. But in other cases, a punch will cause a person to lose consciousness and strike their head on a hard surface.

The impact is similar to being hit over the head with a block of concrete, Mr Bew said. Many one-punch killings involve young men, often in drink-fuelled, random acts of violence. But Finola Farrant, a criminologist at the University of Roehampton, said the circumstances of cases often varied dramatically. These can range from unprovoked assaults, to people who have landed fatal blows in self-defence. In some cases arguments between close friends have resulted in a fatal punch. Last October, Richard Eveleigh was jailed for killing his best friend of 45 years, Paul Lightowler, with a single punch in what the court heard was a "silly" row.

Dr Farrant said the question for courts to explore in these cases was the extent to which defendants should be culpable for someone's death when they may not have intended - or even realised - that one punch could kill.

Indeed, such is the shock of those unintended consequences that the attackers and their families may come to see themselves as victims too, she added. Jacob Dunne was 19 when he killed year-old trainee paramedic James Hodgkinson with one punch in He was sentenced to 30 months' imprisonment for manslaughter. Damage to the brain stem can be a life threatening injury. If the hit person loses consciousness and falls, they may hit their head on the ground or a piece of furniture.

The sound will be something like two snooker balls colliding. This might result in a fractured skull. Once again their brain will bounce around in their skull, creating further trauma.

Like any part of the body, when injured the brain swells. Swelling of the brain can cut off access to blood by squeezing shut the arteries and blood vessels that supply it. After eight to 10 seconds without fresh blood to the brain, consciousness is lost. After four to six minutes without the oxygen the blood supplies, the brain begins to die. As the brain swells, pressure inside the skull increases.

If the brain swells larger than the skull that holds it, it may begin to press outside of the skull into the nasal cavity, out of the ears and through any skull fractures. Surgeons may have to drain fluid from around the brain or remove part of the skull to help ease the pressure of the swelling. Trauma to the brain may also cause a haemorrhage , or bleeding inside the skull or brain. Without immediate treatment, this condition is deadly, as is a hematoma, or blood clot, that forms from the escaping blood.

The brain has limited ability to heal itself.