Assessment of Tremors in Parkinsonism Patients Using a Wearable Sensor Device is a prospective observational single arm cross sectional validation study with longitudinal follow up. The study aims to validate wearable sensor tremor measurements against clinician rated MDS UPDRS tremor scores and to evaluate the reliability, responsiveness, and feasibility of device derived metrics over time. Primary assessment will be agreement between device metrics and clinical scores at Day 1, Day 30, and Day 90. Secondary assessments include responsiveness to medication changes, test retest reliability, feasibility of device use, diagnostic accuracy, and stability of tremor burden. The study includes adults aged 18 to 80 years with clinically diagnosed Parkinsonism and detectable tremor, and excludes those with interfering movement disorders, implanted devices, severe cognitive impairment, unstable illness, or inability to attend follow up visits. A total of 80 participants will be enrolled with an expected 60 completing the Day 90 visit. Total duration is approximately nine to eleven months.