Rehabilitation: Gait analysis and training in Virtual Reality

"Clinical and rehabilitation facilities use instrumental 3D gait and motion analysis (3DGA) as a state-of-the-art tool for the objective and quantitative study of human motor function," says Professor Dr. Brian Horsak from the St. Pölten University of Applied Sciences. The 3DGA method extensively supports the different steps that include diagnosis, medical findings, surgical planning, and therapy evaluation.

Horsak adds that although many clinical facilities collaborate with research centers, the scope of these activities tends to be limited due to the demanding clinical environment. "Oftentimes, there is also a lack of connection and communication with other fields of science and technology," explains the senior researcher.

In addition to its focus on the field of health and social sciences, the St. Pölten University of Applied Sciences also fosters highly specialized competencies in machine learning, visual analytics, and mixed reality. Not only do these methods promote clinical research and development, they can also offer new approaches to preventive, therapeutic and rehabilitative practice. The "Laboratory for Capturing Motion and Augmenting Environment in Motor Rehabilitation" – abbreviated ReMoCap-Lab – combines all these disciplines. "Thanks to intensive industry networking, the ReMoCap-Lab will ensure that the resulting developments turn into products that reach and benefit patients," says Horsak.

In the next two years, Horsak and his team want to actively study two use cases. The first use case applies machine learning and visual analytics methods to automatically detect patterns and abnormalities in clinical gait analysis data. The aim is an assistance system that supports diagnosis and medical findings. "We solely want to augment medical findings," emphasizes Horsak. The physician still makes the final decision. Even though automatic pattern recognition is nothing new in medicine, the background processes are generally still not easy to understand. "That’s why our goal is to reproduce these normally invisible and frequently difficult learning processes for health professionals by using special visualization techniques from the field of visual analytics. This is called 'explainable artificial intelligence'."

The second use case will combine 3D motion analysis and virtual reality. This allows an accurate three-dimensional capturing and recording of human movements. The method is similar to motion capture technology, which is used in animated movies. The ReMoCap-Lab team wants to use this approach to develop a virtual or mixed reality motor rehabilitation feedback system. At present, the researchers keep in touch with business partners and clinical facilities to identify relevant rehabilitation settings. This process can be envisioned as follows: "The motion analysis system accurately records the movements of patients. The analysis takes place during a rehabilitation session. To do this, the patient wears a head-mounted display – in this case virtual reality glasses. We can subsequently use the real-time motion analysis data to display targeted feedback in the virtual reality environment."

The "Gait Real-time Analysis Interactive Lab" – or GRAIL – at the Chemnitz University of Technology (TU Chemnitz) also takes advantage of virtual environments to gait analysis. The GRAIL makes it possible to study patients in more realistic settings than was previously possible. "In this setting, virtual reality is not just created in a visual and acoustic sense, but also physically via a hydraulic, dual-axis, portable treadmill," explains Professor Dr. Claudia Voelcker-Rehage, Professorship of Sport Psychology (with focus on prevention and rehabilitation) at TU Chemnitz. This makes it possible to simulate walking on an uneven forest path, hill or a rope bridge for example. The virtual reality simulation is created by integrating the visual system, as well as tactile sensation and sense of balance.

Actual GRAIL applications chiefly pertain to the rehabilitation and research of different orthopedic and neurological disorders. "It’s important that patients are still physically able to stand or walk on the treadmill with as little support as possible," explains Voelcker-Rehage. During the analysis, the patient is secured with a ceiling-mounted support system and belt and is also able to use a handrail if needed. Another option is to move on the treadmill using aids like crutches, rolling walkers or prosthetics.

Needless to say, this enables a personalized approach to rehabilitation, prevention and physiotherapy. Based on different movement parameters, the physiotherapist can select proper exercise scenarios, analyze the patient’s progress and make exercise adjustments to fit the patient’s unique needs. This facilitates a targeted approach to training.

Horsak and his team at St. Pölten University of Applied Sciences also recognize the major potential of these digitized applications. They want to use this approach to actively shape the future of motor rehabilitation. Horsak is sure that "digitization offers new and exciting opportunities we must apply in rehabilitation and physiotherapy in the future to provide the best care possible for every patient." This gave way to the creation of the “Center for Digital Health Innovation” at the University of Applied Sciences.

Voelcker-Rehage is likewise confident that the digitization of rehabilitation and prevention offers multiple benefits and advantages: "The GRAIL can pave the way for a more personalized and standardized gait training that also targets specific movement parameters." What’s more, the rehabilitation process can be documented based on scientific criteria and objectively managed and adapted.

Whether it’s at the TU Chemnitz or the St. Pölten University of Applied Sciences – both teams see another major benefit in the resulting increased motivation, especially when patients receive real-time feedback on their walking patterns and if there is a chance to incorporate gamification aspects into the rehabilitation measures. Those are just some of the reasons why three-dimensional virtual or mixed reality, which can facilitate both a personalized and standardized interaction with the patient has the potential to create more interesting training incentives in the future and make the rehabilitation process and physiotherapy even more attractive.