A sports training aid comprising a body unit, attachable to a person's body or the person's sports implement, is provided with a positioning sensor module; a feedback stimulator; and a processor. The sports training aid is configured to provide instantaneous feedback on motion faults of a studied sports motion, and the body unit is intended to be attached to a person's body (or a person's sports implement) at a representative location, the location being bound to travel a path representative of the studied sports motion, and the positioning sensor module comprises acceleration sensors and gyro sensors, and the processor is configured to determine a still position corresponding to an event wherein the body unit is determined to be still, to keep track of the sensor module's movements relative to the still position, and to activate the feedback stimulator in real time, upon detection of a sports motion fault.