grammatical number - "Person with a trauma" or "person with trauma"

In academic writing, I frequently run across texts where the determiner is dropped when a person is described as having a medical condition or having suffered an injury. Moreover, a singular noun is sometimes used instead of a plural one. Here are some examples.

• "Twenty percent of the nurses suffered back injury"


• "We identified [...] residents [...] who had been diagnosed with neck injury."



• "patients who had suffered minor closed head injury"

Is this standard usage in English? To me, a non-native speaker, it seems off and should be rewritten:

• "Twenty percent of the nurses suffered a back injury"


• "We identified [...] residents [...] who had been diagnosed with a neck injury"


• "patients who had suffered minor closed head injuries"

Answer

I suspect the lack of determiner reflects the fact that the injury or trauma in question is both countable and not countable. A man shot in the arm might have a broken arm, a bruised arm, a lacerated arm, and a punctured arm. You could say these are all injuries to the arm. But you could also describe the entire affair as injury or an injury to the arm. Omitting the determiner means not having to choose whether the injur[y is|ies are] countable, or put another way, avoids the need to quantify.