CHICAGO (Reuters) – Fatter rear ends are causing many drug injections to miss their mark, requiring longer needles to reach buttock muscle, researchers said on Monday.

Standard-sized needles failed to reach the buttock muscle in 23 out of 25 women whose rears were examined after what was supposed to be an intramuscular injection of a drug.

Two-thirds of the 50 patients in the study did not receive the full dosage of the drug, which instead lodged in the fat tissue of their buttocks continued . . .