Measuring leg strength in movement disorders

Inclusion criteria: Patients who have been diagnosed with Parkinsons disease (PD) or Parkinsons disease-related disorders and are currently hospitalized for treatment in the Department of Neurology at Juntendo University Urayasu Hospital will be considered for inclusion in this study. Among these patients, those who are currently undergoing rehabilitation will be approached and provided with a full explanation of the study. Only those who provide written informed consent will be enrolled as study participants, provided they meet all of the following inclusion criteria 1.Age 20 years or older at the time of consent 2.Clinically diagnosed with PD or a related disorder (e.g., multiple system atrophy or progressive supranuclear palsy) 3.Hoehn and Yahr stage 1 to 4 4.Able to provide written informed consent based on sufficient understanding of the study, following a thorough explanation, and of their own free will Exclusion criteria: Participants will be excluded from the study if they meet any of the following criteria: 1.Presence of comorbid conditions that may affect muscle strength, such as orthopedic disorders or psychiatric/neurological diseases 2.Severe dyskinesia that interferes with accurate assessment of muscle strength 3.Determined by the principal investigator to be otherwise unsuitable for participation in the study