Increased rugby player strength causes 'nuts and bolts' of body to collapse
The joints, tendons and ligaments of rugby players are beginning to buckle under the pressure of bone-crunching tackles it would seem, as World Cup withdrawals at this year's event are double the 2011 group stage total.
The number of players who have had to bow out early has renewed medical concerns about the risks and hazards of the sport. When the 40 pool matches were completed, 34 players had withdrawn through injury - double the amount sidelined at the same stage of the 2011 tournament.
Since the first World Cup campaign in 1987, the size of players has dramatically increased - forwards by 8.9kg (20lb) and backs by 8.5kg (18lb) - which has, in turn, led to an escalation in the number of players suffering particular injuries.
But while players are getting bigger, their joints are not getting stronger, according to Eileen Murphy from the Dublin Spine and Sports Physiotherapy Clinic.
She says the game's obsession with size and power means the "nuts and bolts" of the body can no longer withstand the ongoing ferocity of modern-day tackling.
The human body can only take so many big hits before it "caves in", she told the Irish Independent.
"Professional players have incredible muscle strength and are increasing their muscle mass all the time. However, what remains unchanged are their joints, ligaments and tendons.
"The spinal, ankle and knee joints are the same - what changes is the tissue surrounding them, which is larger.
"A rugby player's body must now cope with the kind of sustained impact which was not the case in previous years.
"The reality is the human body hasn't adapted to this situation as yet.
"The velocity at which they move, and the size of the impact when they tackle, can cause immense damage to human tissue - particularly for the neck, back and knees."
Ms Murphy also described some of the current All Blacks team as "enormous".
She also pointed out that some players are more prone to getting injured because their bodies are tired.
"Fatigue is probably a factor. Obviously, the fitter and stronger the player is, the more he can withstand fatigue.
"But there is a limit to what a player can cope with at the end of a very gruelling season."
Adrian McGoldrick, a GP and Medical Officer of the Turf Club, says the toll in the never-ending quest for power and pace is having a huge impact on the players involved.
He also said, while professional rugby players have never been fitter, stronger or faster, the result is an "astonishingly physical, high-intensity sport".