"Concussion" is another case of a troubled movie about a troubling topic: namely what the NFL knew about long-term brain injuries to players and when.

"Concussion" is another case of a troubled movie about a troubling topic: namely what the NFL knew about long-term brain injuries to players and when.

One thing viewers should know going in is that this is not a big-picture movie about this issue, but more of a biopic about the doctor who was key to discovering what was really going on with former players. This focus is problematic at times when the larger spectre is looming.

Dr. Bennet Omalu (Will Smith) is a Nigerian immigrant working as a pathologist in the Allegheny County coroner's office. He's a meticulous and kind doctor, taking a somber moment with each corpse while attempting to decipher the story their lifeless body can tell him about his or her death.

When Omalu dissects the body of beloved Pittsburgh Steelers center Mike Webster (David Morse), he is baffled by how a seemingly healthy 50-year-old former pro football player's life could end the way it did. Struggling with dementia, Webster was living out of a pickup truck until his death.

Working tirelessly and funding his own reseachresearch, Omalu theorizes that repeated head trauma played a role in Webster's deteriorating mental state - a seemingly obvious theory that flies in the face of decades of NFL-approved research.

Writer-director Peter Landesman adapted "Concussion" from a 2009 GQ article on Omalu by Jeanne Marie Laskas. The focus on Omalu makes for some interesting details about his life as an immigrant doctor with a working visa.

The issue here is that viewers are likely expecting a larger story, and it's one that Landesman tries to tell in the margins. As more player deaths come to light, the powerful NFL works to suppress Omalu's theories. These include some of the creep intimidation tactics you'd expect of the mob - or of the cigarette industry as seen in "The Insider."

Smith gives a spirited if one-note performance as Omalu. His altruism never waivers, even as the impact on his professional and personal life increases.

As the end result is largely a biography, some of the surrounding details get short shrift and lose impact, particularly the everyday struggles of the players who find their minds slipping away and don't know why.

"Concussion" fumbles on the larger story and isn't much more successful in shedding light on its main character.

"Concussion"

Opens Christmas Day

2 stars out of 4