Harvard Medical School announced Tuesday a $100 million grant from the union representing NFL football players for an unprecedented study into the health of participants in the violent sport.

The National Football League Players Association awarded the funds for a 10-year initiative dubbed the Harvard Integrated Program to Protect and Improve the Health of NFLPA Members.

The aim is to make a multi-pronged study into the health of players and ways of treating and preventing injuries and illnesses.

NFL games have come under growing scrutiny in the last few years for what critics say is a dangerous rate of concussions after blows to the head. Some have also drawn links between the onfield physical traumas and off-field mental health problems, including suicide.

"Professional football players often develop severe disability related to a number of health problems, including head trauma, heart problems, diabetes, and joint and other skeletal injuries, as well as psychological stress," Harvard said in a statement.

Researchers will start by picking 100 healthy and 100 unhealthy players from across the country and test them for what Harvard said would be a "biological profile of illness."

"Our goal is to transform the health of these athletes," said Lee Nadler, Harvard Medical School dean for clinical and translational research. "In order to extend the life expectancy and quality of life of NFLPA members, we must understand the entire athlete, all the associated health risks, and all of their interactions."