The new concept of “buckling force” in erectile dysfunction:

So Udelson developed a model that would predict the buckling force, based on penis length, circumference and the ease of expandability over a range of ICPs – it is a direct adaptation of 200-year-old column buckling research by Swiss mathematician Leonard Euler.

Udelson tested the model against 57 men with erectile dysfunction. Each was measured by slowly injecting their penises with saline solution until erect. Udelson then applied a force to the tip of the penis until it started to bend, the first sign of buckling.

The model correctly predicted the buckling forces for 80% of patients – forces ranged from about 2 kilograms to just 0.3 kg given a pressure of 50 mmHg. But the buckling force during intercourse doesn’t just rely a man’s blood flow and penis shape, it also depends on his partner’s vagina.

(via kottke)