A motion detection method, a motion detection program, and a terminal device enabling detection of a tremble probably related to the health condition are provided. The motion detection method includes executing, with a computer (200), acquiring number of steps and a trembling number based on detection values of an acceleration sensor (14), and a time period in which the number of steps and the trembling number are detected, from a terminal device (100). The motion detection method also includes executing, with the computer (200), 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. The motion detection method also includes executing, with the computer (200), generating information based on the trembling number when the trembling number exceeds the threshold as a result of the determining, and notifying the terminal device (100) of the generated information.
