An information processing apparatus (100) acquires measurement information regarding a movement of a patient from a measuring instrument (101). The information processing apparatus (100) detects a walking period (p1-before) and a walking period (p1-after), based on the measurement information. The information processing apparatus (100) specifies a boundary period (p1-center) between the walking period (p1-before) and the walking period (p1-after). The information processing apparatus (100) calculates, based on the measurement information, dissimilarity of a peak amplitude of an vertical acceleration to the walking period (p1-before), and similarity of a peak interval of a vertical acceleration to the walking period (p1-after), in the boundary period (p1-center). The information processing apparatus (100) determines, based on the calculated dissimilarity and similarity, whether or not the boundary period (p1-center) is an abnormal motion period.
