Sex dolls rely on a simple yet effective internal framework that enables a range of natural-looking positions. Most setups feature a skeletal core with a combination of ball-and-socket joints, hinge joints, and swivels. Ball-and-socket joints allow fluid shoulder, hip, and neck movement, while hinge joints control bending at elbows and knees. Swivel joints enable rotation and fine-tuning of alignment in wrists, ankles, and sometimes the jaw. The result is a versatile range of poses without sacrificing stability.

Maintenance revolves around keeping these joints clean and properly aligned. Dust and debris can limit motion, so wipe joints gently with a damp cloth and avoid abrasive cleaners. If a joint begins to feel stiff, a tiny amount of silicone-safe lubricant applied sparingly at pivot points can restore smoothness. Never force a joint beyond its natural range, as this can cause wear or dislocation of the internal skeleton. When disassembling for cleaning or repair, document how parts fit together so reassembly restores the original geometry. After reassembly, test each joint carefully—lift, bend, rotate, and gently stretch to confirm even resistance and stable alignment. Proper care preserves articulation and extends the doll’s usable life, ensuring safe, realistic posing over time.