Twenty-one years have passed since the NFL first acknowledged concussion might be a problem in the sport. Not a major one, mind.

"We discuss it on the list of things every time we have a league meeting," said Dr Elliot Pellman at the time. "But we think the issues of knees, of drugs and steroids and drinking are far greater problems, according to the number of incidents."

Of course, that the league originally appointed Pellman, a rheumatologist rather than a neurologist, to head up its Mild Traumatic Brain Injury committee spoke volumes about its approach. More than two decades on, it is reaping what it sowed.

That committee was set up in 1994, the year Tony Dorsett was inducted into the NFL Hall of Fame. During an illustrious career with the Dallas Cowboys, he rushed for nearly 13,000 yards and established himself as one of the best running-backs of the era. Earlier this month, Dorsett spoke eloquently and poignantly about his recent diagnosis with Chronic Traumatic Encephalopathy (CTE), the degenerative brain disease he and so many of his former peers believe has been caused by taking repeated hits to the head.

Battling depression

A man who spent his professional life braving defenders bent on stopping his progress by any means necessary, Dorsett now battles depression, paranoia and memory loss on a daily basis. This is why he and an estimated 5,000 other former players are part of a class-action lawsuit against the NFL alleging the league failed to provide them with adequate protection against concussion and knowingly downplayed the link between head injuries and brain damage.

The case originated in 2011 when seven former players first filed suit, motivated by burgeoning evidence that a couple of generations of household names were struggling in retirement with symptoms like violent headaches, forgetfulness, mood swings and depression. By then, one study had already found NFL players 19 times more likely to develop dementia than the general population.

Ray Easterling, a one-time Atlanta Falcon, was among the initial litigants. Within a year, he killed himself and a recurring and disturbing motif of suicide runs through this sordid tale.

When former Chicago Bear Dave Duerson chose to end his life in 2011, he shot himself in the chest and left a note specifically requesting his brain be donated to the doctors then investigating links between NFL careers and CTE. Duerson knew there was something seriously wrong and the autopsy found he had the disease. Fifteen months later, after the former San Diego Chargers' icon Junior Seau turned a gun on himself, his diagnosis was identical.

Back when Seau made his NFL debut in 1990, a 21 st 6lb lineman was still considered a freakish presence. By the time Seau retired in 2009, behemoths of that size and power had become the norm rather than the exception. Players had gotten considerably bigger, stronger and faster. In a scenario that will sound eerily familiar to rugby people, the hits were harder and the impact of each one magnified.

‘Gotta play hurt’

In a sport where the machismo “Ya gotta play hurt” mantra is drilled into children from an early age, a price eventually had to be paid. A price that the American legal system is currently struggling to put an exact number on.

Indeed, the labyrinthine workings of the class action lawsuit wending its way through the courts should serve as a cautionary tale to all sports about what happens when you fail to take concussion seriously enough, early enough. After the two sides reached an initial 65-year settlement for $765 million in August, 2013, Judge Anita Brody subsequently ruled that this wasn't going to be sufficient.

“Even if only 10 per cent of retired NFL football players eventually receive a qualifying diagnosis,” wrote Brody, “it is difficult to see how the monetary award fund would have the funds available over its lifespan to pay all claimants at these significant award levels.”

Brody ordered a renegotiation so that every former player will have access to compensation if needed. While a deal on that litigation is apparently imminent, and the NFL can claim, belatedly, to have improved concussion protocols on the field, the ramifications continue to percolate far beyond the professional ranks.

Last year, Daniel Bukal, a once-promising teenage quarterback, filed suit against the Illinois High School Association. Having suffered several concussions on the field, he's alleging those in charge didn't do enough to protect student athletes in their care. Others are heading down a similar legal path.

Last year, Debra Pyka also made national headlines. She filed suit against the Pop Warner Youth League in a Wisconsin court. Pyka claims her son Joseph took his own life at just 25 because the multiple concussions he suffered from age 11 caused CTE.

From suburban fields where young boys first place oversized helmets on their heads to the most storied arenas in the US, concussions, lawsuits and gridiron are now forever intertwined.