Development of Digital Services for Parkinson's Disease

Inclusion criteria Participants with Parkinson's \[Phase 1,2,3,4\] * Diagnosis of idiopathic Parkinson's disease (UK Brain Bank Criteria) or other appropriate condition specific scale \[stroke, multiple sclerosis, arthritis or osteoporosis\] * Able to self-report history of daily gait freezing and/or festination for people with PD or gait and/or transfers affected by condition * Able to walk unsupported or using an aid for at least 5 minutes and satisfactory completion of the Canadian PARQ and if over 69 used to carrying out this level of exercise * Adult (+18 years old) * Normal or corrected-to-normal vision (Snellen Visual Acuity \> 12/18) or safe to mobilise with support * Montreal Cognitive assessment score \>21 or ability to follow 2 stage commands Healthy participants \[Phase 1,2,3\] * With no long-term conditions affecting movement * Able to walk unsupported or using an aid for at least 3 minutes and satisfactory completion of the Canadian PARQ and if over 69 used to carrying out this level of exercise * Adult (+18 years old) * Normal or corrected-to-normal vision (Snellen Visual Acuity \> 12/18) or safe to mobilise with support * Montreal Cognitive assessment score \>21 or ability to follow 2 stage commands Exclusion criteria Participants with Parkinson's * Any physical or mental condition affecting ability to safely participate in this level of activity and capacity to understand testing as demonstrated by ability to safely follow commands and pass the PARQ by the research team. * Cognitive impairment affecting ability to safely participate and follow instructions * Any injury or disorder that may affect balance (other than Parkinson's or referring primary condition) * Any skin conditions or broken skin in the calf and behind knee area * Deep brain stimulation or pacemaker implants or other implant that may interfere with the measurement system * Medications likely to affect eye sight or use of virtual reality sytstem Healthy participants * Any physical or mental condition affecting ability to safely participate in this level of activity and capacity to understand testing as demonstrated by ability to safely follow commands and pass the PARQ by the research team. * Cognitive impairment affecting ability to safely participate and follow instructions * Any injury or disorder that may affect balance (other than Parkinson's or referring primary condition) * Any skin conditions or broken skin in the calf and behind knee area * Deep brain stimulation or pacemaker implants or other implants that may interfere with the measurement system