An injury report was a type of report that Starfleet personnel were required to fill out to describe how another crewmember was injured while on duty. Such a report most likely was submitted to the chief medical officer and first officer of a starship.
In the 2270s, Starfleet requested damage and injury reports from USS Enterprise following their encounter with V'ger. Captain Kirk instructed Uhura to report Willard Decker and Ilia as casualties. (Star Trek: The Motion Picture)
In 2365, William T. Riker reported that injury reports on the USS Enterprise-D were increasing after the starship became infected with a computer virus that had also afflicted the USS Yamato. (TNG: "Contagion")
In 2368, Captain Jean-Luc Picard asked Doctor Beverly Crusher for an injury report as he entered sickbay on an away team that escaped from the surface of a moon of Mab-Bu VI. She informed him that most of the injuries were minor abrasions, adding that Riker's broken arm was the worst injury sustained. (TNG: "Power Play")