1. Clashes and bashes
Since rugby turned professional players have become bigger, stronger and faster.
Members of the current England team are, on average, an inch taller and a stone heavier than their Grand Slam winning predecessors of 1992. When players of this size collide, the forces can be similar to what you'd experience in a car crash.
Part of the reason rugby players can take these hits is due to genetics – they are born tough. Some argue they need to be good at healing quickly too. Besides that, conditioning, medical care and coaching play a huge part.
Preparing for the big hits is essential to minimise the damage.
As well as training to get bigger and stronger, players also follow 'prehab' training programmes which strengthen areas of the body often injured - like ankles, knees and shoulders.
3. Mind games
The sound of the big thumping collisions can be heard from the sidelines but some players say the hits don’t actually hurt that much at the time.
Sports psychologist Dr Richard Cox has worked with the Scottish rugby team. He says players prepare their bodies for the big hits. “Guys warm up by engaging in contact so their bodies get used to it. Because of the adrenaline flow, the injury isn’t felt anywhere near as much as it is the next morning.”
Dr Cox says players also need to be able to anticipate hits. “The ones that cause the damage come out of the blue, when you don’t see the hit coming you can’t anticipate it, you can’t set yourself for it.”
4. Medical care
With so many big demands on players' bodies, high quality medical care is essential.
Going for surgery after injuries could be seen as part of the job of a professional rugby player. Former Scotland international Rory Lamont has had 18 operations for rugby injuries – though he's probably had more than most.
5. What are the long term impacts?
While the injuries from big hit rugby can usually be managed in the short term, what will happen to players' bodies in later life?
JPR Williams, doctor and Wales player 1969-1981
I think the accumulation of hits does take its toll. My playing colleagues and I are in our 60s now and most of us have had a joint replaced. Today's players will be having them 20 years earlier so they'll be having their hips and their knees done at the age of 40.
Dr William Stewart, consultant neuropathologist
We can't be sure exactly how repeated concussions affect the brain over the long term, more importantly, who might most be at risk of long term damage. What we can say is that these injuries need to be taken seriously. Shoulders can be rebuilt, hips can be replaced but if you damage your brain you can't get it back. This is an area where much, much more research needs to be done.
Richard Hill, England 1997-2005
I retired in 2008 and had a total knee replacement a year later. I knew in the latter years of my career that it would have a knock-on effect. With the state of my knee I knew future treatment was inevitable but I probably hoped I‘d get further down the line. I don’t think you take part thinking that will be the end product – but in the majority of sports you’re probably stretching your body more than most.
Dr Martin Raftery, IRB Chief Medical Officer
Player welfare is the IRB’s number-one priority. What we know now about player recovery and the prevention and treatment of injuries is vastly superior to what it was. Research suggests that injuries in elite rugby have not increased since 2002. Around 50% of injuries are potentially avoidable, down to poor technique or over-training and we are establishing a player load working group to review this critical area.