Virtual reality balance-based training in patients with Parkinson's disease

The main aim of the study is to assess in objective way the efficacy of custom-made virtual balance clinic system dedicated for patients with Parkinson's disease. Patients diagnosed with Parkinoson's disease (stage I-III) will be allocated to one of two experimental groups: Group A: 12 training sessions of balance-based VR training Group B: conventional balance training Group A - participants will receive a 4-week balance-based VR intervention. The exercises will be administered for a total of 12 training sessions (3 training sessions per week). Duration of each session: approximately 30 minutes The VR balance training system will comprise two integrated devices, a custom-made force platform and a 3D measurement system based on time-of-flight cameras (Kinect sensor). Both devices will be used to control and verify movement execution. Seven games will be used for training balance. Through avatar technology, images will be projected on the 65-inch screen which will be situated 2m away in front of the participant. The participants will be introduced inside the video game as an avatar character which provided instantaneous visual feedback about patient’s movement execution. In each training session participants will practice the static posture maintaining, dynamic weight shifting, single leg standing, leaning in different directions, trunk rotation, steps making. Games will be adapted to the subject’s individual capabilities by changing several parameters in each game (i.e. movement velocity, frequency, range of weight distribution etc.) The physiotherapist always will attend the sessions and supervise for safety. Patients will always practice in "On" state. After inclusion in the study, patients will be asked to refrain from any other balance training. The following measurements will be performed to objectively assess therapy effects: I. Functional balance will be assessed using Limits of stability (LOS) test in forward direction, Functional Balance Test and Timed Up and Go test (TUG): a) The LOS test will be repeated 3 times. Each trial will be divided into three phases: 1st phase - quiet standing (10s), 2nd phase - transition to maximum leaning position, 3rd phase - maintenance of the maximal forward-lean. In this task participants will be asked to stand quietly during the first 10s of the trial, then, after signal tone, to lean in the forward direction as quickly as possible without moving the feet and to maintain this position up to the end of the trial. b) In the Functional Balance Test, the participants by leaning the body will rapidly shift the center of foot pressure to areas indicated on the screen without moving the feet. The COP point will be drawn in real time on the screen of the monitor, that will be placed in front of the participant. During the test, two areas with specific width and distance between them will appear alternately. The Functional Balance Test trial will be repeated 3 times. c) Timed up and Go test will be repeated twice. II. Static Stabilography (quiet standing test) will be carried out using custom-made force platform with integrated sensors to register center of foot pressure (COP) displacement. Subjects will stand barefoot as still as possible on the force platform, maintaining their arms by their side while keeping their head straight. A total of 6 trials will performed: 3 trials with eyes open with gaze fixated at a reference point located 2 m away in front of the platform, and 3 trials with eyes closed. III. Subjective assessment will be carried out with Berg Balance Scale. All objective outcomes (postural stability and functional balance tests) and subjective assessment will be measured on 4 occasions: prior to intervention (baseline values), after 1, 6 training sessions and after the completion of the 4-week program.