One of two common terms commonly used by National Hockey League clubs when describing injuries to their players, the 'UBI' is any injury above the waist. In practice, it is almost always one of two things: a neck or head injury—including a concussion—or a shoulder/arm injury such as a broken bone or a separated shoulder. It can also refer to chest injuries such as a back or rib injury. Concussions have recently become a special case, but as recently as 2014 they were still lumped into this grouping. The UBI can be as mild as a stinger or as severe as a career-ending injury.
Unlike the National Football League which mandates detailed injury disclosure, the NHL permits teams to be as unhelpful as possible when reporting injuries, purportedly to prevent opposing players from targeting the injury. Interviews with players have generally shown that none of them believe that this would occur, however the policy remains in place. In 2008 when the policy was announced the New York Times reported the wording as follows:
Clubs no longer are required to disclose the specific nature of player injuries. Clubs are, however, required to disclose that a player is expected to miss a game due to injury, or will not return to a game following an injury. Clubs are prohibited from providing untruthful information about the nature of a player injury or otherwise misrepresenting a player's condition.
This led to the title phrase, which was already in use, becoming the predominant catch-all description. The Toronto Star attributes its ubiquity to former Toronto Maple Leafs coach Pat Quinn, who may have first used it in the 1999 playoffs. It caught on, and once the league's rules changes as described above, teams settled on it and its counterpart the lower body injury (LBI) almost exclusively.
Until quite recently the UBI was used to conceal concussions. There's an ongoing lawsuit about whether the NHL concealed what they know about concussions from the players. It's a mess because the league was in some ways breaking ground with concussion research, but in other ways apparently withholding that same data. But as the true health cost of concussions has become apparent, the NHL has instituted a new concussion protocol that takes decisions about player health in this area out of the club's hands and into those of independent doctors. As a result, when a player is in concussion protocol this generally becomes known, and as such the UBI and the concussion have to some extent diverged. Not that an NHL coach will draw the distinction!
And what about a middle body injury? The NHL seems to acknowledge no such thing. The Toronto Star put the question to Pat Quinn, and we'll give the 'Big Irishman' the last word:
You media guys all have a middle-body injury because you’re all a pain in the ass.