This study presents a low-power wearable system able to predict a fall by detecting a pre-impact condition, performed through a simple analysis of motion data (acceleration) and height of the subject. The entire detection system uses a single wearable tri-axis accelerometer placed on the waist for the comfort of the wearer during a long-term application. As soon as an imminent fall condition is reached, a capacitive discharge ignite a device to trigger the combustion of an energetic material to generate the gas. The use of gas-generating energetic composites makes it possible to miniaturize the system and reduce weight, thus increasing comfort.