SAFE-PD - Stepping to Avoid Fall Events in Parkinson’s disease

Participants allocated to the intervention group will receive volitional and reactive step training. Volitional step training will involve playing home-based exergames for 12 weeks. The training involves a custom-built software, operating on a supplied personal computer and stepping mat. Stepping games will be used to train balance and step reaction time, as well as executive functions. A research assistant will visit each participant’s home to install the system and instruct how to use the equipment. Participants will also receive a follow-up home visit in the following week to ensure safe use and progression of training. Weekly training dose will progress from 40+m minutes in weeks 1-2, 60+ minutes in weeks 3-4 and 80+ minutes in weeks 5-12. The training will be recommended to be split between 3 or 4 sessions per week and will be monitored via data transfer to a web application. Participants who do not engage in the minimum weekly training dose for two consecutive weeks will be contacted by telephone to encourage adherence and also address any barriers to participation. Intensity and complexity of training will be progressed as performance improves by increasing the level of difficulty of the games. Additional visits and telephone support will be provided for those participants experiencing difficulties. Reactive step training sessions will be undertaken in weeks 4 and 8. Participants will visit NeuRA to undertake two individual sessions (100 minutes in total). Each session focuses on balance recovery from mix of trips and slips. A novel trip- and slip-perturbation system built on a 10-m walkway consisting of 50cm x 50cm wooden decking tiles will be used. Participants will be secured with a ceiling-mounted full body harness to avoid any contact with the ground. Participants will practise recovering their balance to trip and slip events. Gait speed during this training will be approximately 80% (or 50 to 100% if adjustment is required) of usual speed using music or metronome with beat corresponding to target cadence. A slip is induced by a movable tile on two hidden low-friction rails with linear bearings that result in a slide of 10-70cm upon foot contact. A trip is induced using a 7-14cm height tripping board that flips up from the walkway at mid-swing using a foot detection sensor. An exercise physiologist and an assistant will supervise each reactive step training session, ensure participants safety, adherence and individualize the training protocol. The tripping board and the slipping tile are undetectable and can be moved to various locations along the walkway so that predictive adaptation (e.g. changing gait with prediction) will be minimized and reactive stepping responses can be specifically trained.