Tracking shaking and arm movement with wearable sensors

Inclusion Criteria: 1. Aged 18 years or older. 2. Clinical diagnosis of idiopathic Parkinson's disease (Hoehn and Yahr stage I-III) or essential tremor. 3. Motor or tremor symptoms confirmed on clinical assessment. 4. Able to walk at least 4 metres independently, with or without a walking aid. 5. Able to provide written informed consent and comply with study procedures. 6. Willing and able to wear the study sensors in clinic and, where applicable, at home. 7. Able to understand study information and complete study materials in English. Exclusion Criteria: 1. A recent major cardiovascular or cerebrovascular event, or another unstable condition that would make participation unsafe. 2. An uncontrolled psychiatric disorder, ongoing substance misuse, active systemic cancer treatment, or another serious illness likely to interfere with participation. 3. Pregnancy at enrolment. 4. Active skin disease or known allergy to adhesive plaster at anticipated sensor sites. 5. Dementia with Lewy Bodies, atypical, vascular, or drug-induced parkinsonism. 6. Previous invasive neuromodulation or neurosurgery for a movement disorder, including deep brain stimulation. 7. Current or recent participation in another interventional study that could affect safety or study outcomes. 8. In the investigator's opinion, unable to complete the study procedures safely.