Inclusion Criteria:

• The eligibility criteria for males is X-linked adrenoleukodystrophy as determined by biochemical determination or genetic testing.
• The eligibility criteria for females is X-linked adrenoleukodystrophy as determined by biochemical determination, genetic testing, or pedigree analysis.
• The Leukoenceophalopathy with brainstem and spinal cord involvement and lactate elevation inclusion criterion is a confirmed DARS2 mutation through genetic analysis.
• For people with cerebellar ataxia, people with diagnoses of cerebellar damage from stroke, tumor or degeneration will be included. Those with a genetically confirmed cerebellar disorder will be asked to provide their genetic testing to note their particular type of ataxia.
• We will also include patients with other neurodegenerative diseases similar to these disorders as determined by chart review and clinical exam.

Healthy Volunteers

• Able to stand for 30 seconds without upper extremity support
• Ambulatory (including use of a cane or a walker)
• Able to walk for 2 minutes

Exclusion Criteria:

• Other medical or psychological conditions which in the clinical judgement of the investigator would interfere with acquiring the study information or performing the exercises safely including but not limited to:

Uncontrolled hypertension, orthopedic conditions, diabetes, seizure disorder, peripheral vestibular loss, severe aphasia, dementia, pregnancy