Final answer:
The proper placement for hand compressions during CPR is the sternum area between T4 and T9 vertebrae, done at a depth of at least 5 cm and a rate of 100 per minute.
Step-by-step explanation:
Proper placement of the hands for chest compressions on Adults and Children during CPR involves positioning the flat portion of one hand on the sternum, specifically in the area between the line at T4 and T9 vertebrae. This allows for effective compression of the heart, facilitating the circulation of blood into the pulmonary and systemic circuits. It's important to compress the chest at least 5 cm deep and at a rate of 100 compressions per minute. Improper placement or technique can cause injury, such as broken ribs or damage to internal organs, hence proper training is crucial.