best pps to hit?

where would be the best pps to hit to drop some one but not kill them. i have herd that the best is the middle of the back but im not sure if that is ture or false i have tryed all of the pps but the one that did the most damage was the one on his neck that hart him bad and he couldn't move much after for a day or two thats why i asking if thats the only and best one to take a person down with out harting the person so i could stop him with out after effects on his body. If you know anything that can help send me some thing that would help me alot

Don't train pressure points without a qualified instructor first off. Wacking someone's neck hard with or without pressure points can cause serious muscle strain or cervical spine injury.

Getting past that and guessing generously that you have instruction but the accident above was a random hit that was too hard, this is the answer to your question according to Dr. Steve Stewart: Most available weapon to the most available target.