OBSERVATIONS A 4-mm Needle Reduces the Risk of Intramuscular Injections Without Increasing Backflow to Skin Surface in

U nintended intramuscular insulininjection increases the variation inthe insulin absorption rate, thereby increasing the risk of hypoglycemia. To reduce the risk of intramuscular injection, shorter injection needles should be tested, particularly in lean patients (1–3). The objective of this study was to measure the distance from skin surface to muscle fascia in lean diabetic patients and to de-termine whether using an experimental 4-mm needle reduces the frequency of in-tramuscular injections as compared with a 6-mm needle. Further, this study tested whether the backflow of simulated insu-lin (test medium) was unchanged using the new 4-mm needle as compared wit