The pelvic floor muscles can improve your posture and even erection
The Pudental nerves (along with P. veins and arteries) come from behind and go into the pelvic floor muscles.
In traditional sitting the nerves and vessels get pressed between the chair and the pubic bone, which is a strong disturbance in the pelvic floor area. Sitting right at the edge of the chair reduces this exposure a bit.
To get rid of the press problem you need to use loose-fitting clothing (underwear) around the pelvis and sit on a two-part saddle chair (more than 30 mm gap). This also helps the testicles to remain in the optimal temperature of 33°C, which is essential to the testosterone and sperm quality. Such saddle chairs are available.
Not using underwear would be healthiest, combined with washing oneself after defecation. This would increase the comfortability of genital health and hygiene a lot, without disadvantages.
For men, the seating pressure exposes one to erectile dysfunctions in addition to prostate problems. The pressure is spread through the pelvic opening into the pelvis.
Poor posture disturbs not only the intestinal flow but also the pelvic bowl and thus the pelvic floor muscles. The pressure in the abdomen area also spreads into the pelvic bowl and flattens the pelvic floor muscles. In particular, after giving birth when the pelvic floor muscles are weak, there is a risk that the lack of exercise, obesity, poor posture and pressure in the abdomen and pelvic bowl create the chronic gynecological deposition, which can become chronic in less than a year after giving birth. After that the pelvic floor muscles can no longer be cured by exercising.
Sitting upright on a two-part saddle chair also activates the pelvic floor muscles. Additional effect can be got by reaching repeatedly downwards. E.g. keep your mobile phone on the bottom shelf and get the pelvic floor muscles in shape without even noticing.
Men should make frequent pelvic floor tension exercises for a few minutes during so-called non-sexual erection, and thus work out the pelvic floor muscles, erection and increase testosterone production.