An acceleration information detecting unit of an acceleration detecting
apparatus having an acceleration sensor with at least one axis that
measures acceleration in a back and forth direction (or a right and left
direction) of a walking person. Acceleration data indicating the
acceleration is sent to a wireless communication control unit. The
wireless communication control unit sends the acceleration data to a
physical movement analyzer using a short-distance wireless communication
method. On the other hand, the wireless communication control unit of the
physical movement analyzer receives the acceleration data that is sent
from the acceleration detecting apparatus using a short-distance wireless
communication method and sends it to a walking speed detecting unit. The
walking speed detecting unit estimates strides and walking period based
on the received acceleration data and calculates the walking speed based
on the strides and the walking period.