Pushing hard, heavy impacts and four-stroke engines were among the theories offered by MotoGP title contenders Marc M?rquez, Dani Pedrosa and Jorge Lorenzo for their 2013 shoulder injuries.

Lorenzo and then Pedrosa both fractured collarbones earlier this year, while rookie title leader Marquez dislocated his shoulder last weekend at Silverstone.

All use the same Alpinestars Tech Air leathers, featuring airbag technology, and ruled out any type of link between use of an airbag and their shoulder injuries.

"I think Alpinestars are doing a very good job. Every time we have some problems, they are very quick to improve," said Lorenzo. "The type of crashes we have in MotoGP are really strong, so we have to keep working in the future to avoid collarbone injuries and these type of things."

Data from Alpinestars showed that Marquez's airbags deployed 0.168s before the initial impact to his left shoulder. Full inflation was recorded 0.048s after deployment.

The peak energy force was 22.55g, largely concentrated on the left shoulder. The airbag remained fully inflated throughout, ensuring the maximum amount of energy absorption. It may not have been enough to prevent a dislocation, but Marquez is confident he would have been worse off without it.

"For me the shoulder injuries are just because we are riding so fast and pushing a lot," said Marquez, who returned to battle for victory in the Silverstone race. "The crashes for Jorge [Assen and Sachsenring] and Dani [Sachsenring] were so strong.

"Mine was a little different, but I don't think the airbag or the leather suit is the reason. With or without an airbag sometimes you will have injuries because we are riding so fast. But for me the airbag is working well."

Team-mate Pedrosa agreed, adding that the type of injuries sustained seems to have changed since the move from 500cc two-strokes to big-bore four-strokes, in 2002.

"In my opinion first of all Alpinestars are doing a very good job developing a modern system for airbags, trying new materials and testing. I think the shoulder injuries are much more related to the type of bike we are using," he said.

"The four-stroke crashes are more or less in this way. In the past people were always hurting feet and hands, now with the four-strokes it is more the shoulders. Also you have to remember that airbags are a new technology that doesn't have a long history and will be perfected in the future."

Marquez will not require surgery for his shoulder injury.