Inclusion Criteria:  Participants must be at least 65 years old; Participants have a clinical diagnosis of probable AD; Participants can read and understand English; Participants must be able to walk independently at least 25 feet; Participants must have fallen at least once in the past 6 months; Participants must be able to stand independently for at least 30 seconds; Participants must have a Mini Mental Status Examination score between 18 and 23.  Exclusion Criteria:  Individuals have ever experienced perturbation training; Individuals have hypotension or uncontrolled hypertension; Individuals exhibit osteoporosis; Participants suffer from coexisting psychiatric disorders, or other neurological conditions, or injuries, etc.