Dubbed "Lystedt Law", the US legislation designed to combat a "concussion epidemic" is named after a 13-year-old schoolboy who almost died playing American football.
Zack Lystedt left the field dazed after banging his head on the ground, but later returned and took a blow to his helmet that triggered bleeding on the brain.
He was saved by emergency surgery and, nine years of intensive physical therapy later, remains wheelchair-bound and has impaired speech.
"We use the term 'no-brainer'," says Cohen of changing public attitudes towards head injuries in sport. "The mantra is 'when in doubt, sit them out'. The younger brain is still developing and is far more vulnerable."
The Australian head and neck injury expert believes legislation is necessary to protect young lives.
"You still hear all sorts of pressure at schoolboy level - 'man up, here's the smelling salts, get back on the field'," he says.
"But it's ridiculous. Anyone who has really considered this issue is well past that, and if we need legislation that stops bad things happening I don't have a problem with that."
Cohen is staging a pioneering trial with the Randwick rugby club that he hopes will help increase understanding of concussion and the long-term risks for players.
The Sydney team that produced Wallaby legends such as David Campese are the first in Australia to wear bio-sensors that record head impacts during Shute Shield games and practice sessions.
Cohen, founder of head and neck injury prevention advocacy group NeckSafe, downloads and analyses information gathered on a tiny "X Patch" sensor which is taped behind a player's right ear.
Developed by US firm X2 Biosystems, it reveals the force and angle of hits to the head - and wild variations in responses. While one player was knocked out with a G force impact of 40, Cohen says others walked away seemingly fine after a hit measuring 160.
"That's two and half times what Muhammad Ali punched at," he says. "And the variation demonstrates how, when it comes to concussion, we're all different."
The research - backed by the Australian Rugby Union and World Rugby - follows similar trials in the US, UK and New Zealand, where AUT University academic Doug King has measured head impacts on adult and junior rugby and league players.
As the data around the risks from concussion grows, so too does concern among elite players and sport administrators.
Following a successful trial, rugby is to introduce temporary head injury substitutions to allow players to be properly assessed for concussion.
Last month America's National Football League (NFL) agreed to a potential $1 billion-plus settlement with retired players who accused the governing body of hiding long-term consequences.
King's studies have shown rugby players suffer far more hits to the head per game, and the rotational element - where the head snaps back or sideways - is more significant.
Cohen hopes the mounting data will lead to protocols that take vital decisions away from coaches, players and even medical staff.
"Before now everything has been conjecture," he adds. "In rugby league we've seen doctors complaining that a player they would not have sent back on was sent back on by the other team's doctors."
This year US researchers will trial a new real-time version of the bio-sensors - leading to the prospect of players being substituted as soon as they reach specific points of impact.
"Let's say the magic G force number is 100," adds Cohen. "I'd like to get to a point where if a player suffers a significant hit within that band, or a series of 30, 40 and 50 hits over a two-week period, we'll say, 'it's time you rest your brain for your own good'."
