A hand-guided ground compaction machine, in particular a vibratory tamper or vibration plate compactor, having a superstructure, a drive device arranged on the superstructure and having at least one drive shaft, a substructure having a compaction plate driven by the drive device, and a sensor device comprising an accelerometer for determining the ground stiffness of a ground to be compacted, wherein the sensor device is supplied with electrical power, in particular solely, by a generator driven by the at least one drive shaft.