A motion detection method includes: acquiring, from a terminal device, number of steps and a trembling number based on detection values of an acceleration sensor, and a time period in which the number of steps and the trembling number are detected, by a processor determining whether the trembling number occurring in a time period with the number of steps of a predetermined number or less exceeds a threshold, out of a time period with the number of steps exceeding the predetermined number, and the time period with the number of steps of the predetermined number or less, by the processor generating information based on the trembling number when the trembling number exceeds the threshold as a result of the determining, by the processor and notifying the terminal device of the generated information, by the processor.
