Watching personalised three-dimensional movements to support practice

Although studies exist demonstrating the effects of single-session action observation training on bradykinesia in patients with Parkinson's disease, research investigating the long-term application of such training remains limited. Furthermore, the broader literature indicates that action observation training has typically been conducted in simulated environments or by using recordings obtained from healthy individuals. The aim of the present study is to examine the effects of action observation training, delivered in a fully immersive virtual reality environment using each patient's own 3D motion recordings, on bradykinesia and other disease-related parameters.

Action observation training has been applied across diverse populations to improve performance and treat pathological conditions. Considering that bradykinesia tends to manifest more prominently in rhythmic movements, studies in healthy individuals have shown that merely observing rhythmic actions can influence spontaneous finger movement speed and lead to changes in motor performance, thereby paving the way for the use of action observation in addressing bradykinesia. In a study investigating the effects of action observation in patients with Parkinson's disease, observing fast rhythmic finger movements was reported to increase spontaneous finger movement speed, and compared with acoustic training, the effect of action observation persisted longer over time. Research on imagery through action observation further indicates that immersive virtual reality headsets, compared to monitor screens, facilitate the development of more distinct spatial rhythmic patterns in the brain. This evidence supports the use of fully immersive VR headsets instead of non-immersive monitor-based systems in action observation training.