I thought I just answered this but who knows, I'm a blunt head
Stretching the ligaments will give new erect gains but the process of elongating the ligs also breaks down cells along the entire shaft. These 2 components working together produce new length gains. As the penis repairs the micro tears along the shaft new cells produce a sort of bridge between the tears and this gives you the length but the ligaments need to be stretched with these deformations for the penis to become longer.
DLD