Arm wrestling, considered by some as entertainment, is also recognised as a potentially dangerous form of competition with arm wrestling injuries on the rise.

One of the most common injuries is a fracture of the humerus, or upper arm as former NRL player Ben Ross discovered on The Footy Show.

His injury was captured for eternity by television cameras and now joins a multitude of online videos demonstrating sickening arm-wrestling fractures.

And it is not only men who experience this injury; women who arm wrestle are just as likely to present with a fracture.

Ross's injury is the most common seen - a humeral shaft fracture, meaning he has broken the arm bone above the elbow.

But how can a person break their arm in something as seemingly harmless as a friendly arm wrestle?

Physics has a lot to do with it. Think levers, braces and opposing forces.

It is a battle between the arm wrestler's rotating shoulder joint and their bent, static elbow working in opposition, with the upper arm bone taking the pressure.

"The main thing is that there is just so much torque going through the humerus," Dr John Arnold, lecturer in exercise science at the University of South Australia said.

"Because you have your elbow fixed and then you are trying to push against the other person, you are then twisting your humerus.

"That motion, which would normally be taken up at the elbow, is actually getting transferred into the humerus.

"So, you are getting a twist in the humerus which usually results in a spiral fracture."

The result is usually a spectacular and cringeworthy bone break and a nasty shock for all.

"It's pretty sickening, especially the audible crack," Dr Arnold said.

Treatment is dependent on the severity of the fracture but usually involves surgical fixation with metal screws and plates followed by a reasonable period of rehabilitation.

Perhaps closer scrutiny of an alternative sport is also recommended.