Abstract: The invention is a self-contained protective device/system designed to protect the hips, pelvis, buttocks, and coccyx areas of the user. The device may be worn outside of the clothing. Because it is small in size and lightweight, it may be easily put on and removed and does not interfere with body movements. It contains the following components: an inflatable air bag folded into pleats, a battery, a gas cartridge, sensors to determine angular motion and acceleration, a triggering/valve mechanism to release the gas and a relief valve. When the user falls, the sensors automatically release gas from the cartridge and inflate the airbag assembly, forcing the folded pleats to fully cover said areas of the user's body. After use the relief valve is opened to release air from the airbag assembly, the pleats are reinserted into the system and the invention is ready for reuse after the spent cartridge is replaced.