TMZ Sports obtained video showing Richie Incognito being detained outside of a gym in Boca Raton, Florida ... and you can clearly see police handcuffed the NFL star before taking him away.
We broke the story ... cops were called to Life Time Gym early Wednesday morning after he allegedly threw a dumbbell at another gym patron. He was taken into custody and placed on an involuntary psychiatric hold.
Sources tell us ... Incognito had been acting bizarrely at the gym the previous day -- but his behavior hadn't turned violent.
We spoke with several people close to Incognito who tell us they've been concerned about the NFL lineman for months ... and have been trying to help him -- to no avail.
Everyone we spoke with had the same message -- including the victim in the gym incident -- they all want Richie to get help.