It is because those areas are commonly used for subcutaneous injections and are easier to inspect, rotate, and avoid when irritated
Targeting toll-like receptors against cancer
When white blood cell production goes wrong, it can tip either way: too few (leukopenia), which leaves the body vulnerable to infection, or too many and abnormal, the hallmark of blood cancers
How do I know if I have a vitamin B12 deficiency
Sinha R, Papamargaritis D, Sargeant JA, Davies MJ
Lot Traceability and Public COA Library One lot number printed on the vial connects to a single consolidated analytical file containing the HPLC trace, mass spectrum, and endotoxin reading