When muscles hypertrophy they tend to fill in the most in the "belly" of the muscle, it's center. When that happens there's some area of separation, where you can visually distinguish say between the biceps and triceps of the upper arm. ((visualize two uninflated beach balls laying one atop the other, then you fill them both up equally, they will still be touching in the center...but the surface area of contact between them will decrease dramatically....see...)) Well... many, not all, pressure points (kyusho, as Mr. Dillman et al, is want to call them) lie along side bones or near the center of a limb. So when the developed muscles separate...they actually provide better/easier/clearer access to SOME nerves.... (not all).... and I think this may be what Mr. Chapel is refering too.
...accurate??
Your Brother
John