The Rack is Good for you

Generally speaking, torture is bad for you. The level of pain that a torturer wants you to feel generally only comes about by extreme injury.
Medieval Europe really had a thing for torture, inventing many horrible ways to do it. Things that crushed fingers, things that crushed skulls, things that terrified you with knives before stabbing the living daylights out of you, and "The Rack," which pulled your arms and legs until all your joints dislocated. All agonizing, incredibly evil tortures.
And yet, modern sports medicine practitioners point out that in lesser amounts,"The rack" would actually be good for you. Wait, what? Apparently if you did it slowly and stopped well before the first hint of discomfort, the gentle pull actually relaxed the joints and muscles. A slight pulling was like a chiropractic massage, only more in line with mainstream orthopedics. (The average chiropractor manipulates joints abruptly, whereas orthopedics suggest slow and gentle manipulation.)
Many things are only painful or pleasurable by degree. The brightness of sunlight on a warm summer's day is pleasant to look at. The brightness of sunlight from staring directly at the sun in unbearable. Music played at your favorite volume is something that we actively seek out and pay money for. Music played at twice that volume causes us pain. A jump in a cold pool on a hot summer's day is a welcome relief from the heat, but if I poured liquid nitrogen on you, you'd probably scream in agony, no matter how insufferably hot the day was.
If you need me, I'll be in the back room. Deploy ratchet!