Effectiveness of Virtual Reality-Based Multi-Therapy Systems for Physio-Psychological Rehabilitation: A Clinical Study

Abstract

The worldwide increase in the number of disorders requiring rehabilitation is weighing more and more on healthcare systems, seriously affecting the quality of life of patients. Emergent technologies and techniques should be used more and more in both physical and psychological rehabilitation, after a thorough study of their potential and effects. Our paper presents an original virtual reality-based system including gamified immersive physio-psychological exercises, which was tested in a clinical setting with 25 patients suffering from various musculoskeletal, neuromotor, or mental disorders. A thorough testing protocol was followed during a two-week period, including repeated trials, progress tracking, and objective and subjective instruments used for data collection. A statistical analysis helped us identify interesting correlations between complex virtual reality games and people’s performance, and the high level of relaxation and stress relief (4.57 out of 5 across all games) which can be offered by VR-based psychotherapy exercises, as well as the increased ease of use (4.26 out of 5 perceived across all games) of properly designed training exercises regardless of patients’ level of VR experience (84% of patients with no or low experience and no patient with high experience).

1. Introduction

The involvement of modern technology with medicine has led, as of late, to outstanding improvements in patient care and treatment. Among these technologies, virtual reality (VR) has emerged as a groundbreaking tool. Our interest in this regard lies particularly in the realm of physiotherapy and psychotherapy, from treating upper limb and spinal cord affections to managing anxiety and panic attacks and learning how to cope with chronic pain. The integration of VR in this context is becoming increasingly necessary, as desirable solutions seem to correlate their effectiveness with immersion [1], a paramount quality of this particular technology.

Worldwide, according to the World Health Organization, there are over 394 million people who would benefit from rehabilitation services, including musculoskeletal disorders (64.3%), sensory impairments (16.4%), neurological disorders (8.7%), mental disorders (3.7%), or others [2]. The global prevalence of musculoskeletal disorders is worrying, with a 123.4% increase from 1990 to 2020. Predictions show that the increase will continue by 115% from 2020 to 2050 [3], reaching worrying levels of years lived with disabilities. Additionally, the prevalence of anxiety disorders, panic attacks, and chronic pain is also extremely high, with millions of people worldwide being affected by these issues [4]. Anxiety disorders, including generalized anxiety disorder, panic disorder, and social anxiety disorder, are among the most common mental health conditions. They can lead to severe disruptions in daily life and overall well-being. Similarly, chronic pain and functional neurological or musculoskeletal disorders, which can stem from various causes involving a lifelong ailment, provoke a decrease in the quality of life and are often the cause of anxiety, which stems from the individual’s reduced ability to manage disruptive physical feelings. Additionally, global issues such as climate change, political unrest, and public health crises like the COVID-19 pandemic have heightened the overall anxiety levels [5].

Individuals struggling with these issues often find their focus shifting from their usual day-to-day activities to battling angst and panic attacks, while also finding solutions for their physical impairments [6]. The constant state of stress and the preoccupation with managing symptoms not only hinders their ability to function normally, but it also lowers their quality of life [7]. The possibility of angst incurring physical trouble infers that the reverse can also be true, with anxiety either being experienced as a standalone condition or as a byproduct of having to deal with constant, unpleasant situations, such as chronic pain resulting from an ongoing illness [8]. Chronic pain itself is a significant stressor that can severely impact an individual’s mental health [9], leading to a vicious cycle. In addition, anxiety is a pervasive dysfunctional emotion that alters quality of life and psychosocial functioning of individuals in their private or professional activities [10]. Anxiety is a well-known secondary accompanying symptom for any medical condition, which appears with more intensity in diagnoses that influence a person’s usual functioning in all sectors of activity [11]. Restrictive physical mobility or any form of motor disability accompanied by pain is one of the medical conditions highly associated with intense levels of anxiety [12]. This psychological reaction to a specific motor impairment is dysfunctional per se, but it also influences the individual’s capacity to recover and to mobilize personal resources to pursue a constant and demanding rehabilitation program. Neurological disorders are associated with anxiety, depression, fatigue, and low self-efficacy [13]. Ineffective management of these symptoms correlates with poor quality of life [14].

The growing incidence of all these conditions [2] calls for action, especially in the form of affordable, accessible, and efficient physiological and psychological rehabilitation techniques. Conventional therapies often involve a combination of medication, classical physiotherapy, and psychotherapy techniques [15], approaches that have a high risk of being dismissed by the patient on account of their repetitiveness or ineffectiveness over time. Additionally, access to high-quality health services can be limited, particularly in rural or economically disadvantaged areas [16]. These are challenges to which we propose a solution, by democratizing how a patient receives their treatment, in the form of professionally supervised software. Furthermore, traditional methods of managing anxiety, panic attacks, and chronic pain, while undoubtedly effective on their own, have limitations [15], which we are hoping to either bypass or extend by moving the same principle into a technologized environment. A very common practice in combating chronic pain is engaging in physical rehabilitation [17], aside from practicing some form of mindfulness exercise aimed at learning to manage the ailment. All the motor or psychological exercises we have designed for this protocol intervention are built around the purpose of increasing the perceived sense of control the patient is experiencing during the process of rehabilitation. Every patient benefited from consistent feedback from the research team and from adjustment in choosing the exercise or level of difficulty in order to increase comfort and sense of control. Recent research in the field of neurological rehabilitation has proven that these types of interventions are effective in improving indicators like depression, anxiety, fatigue, or self-efficacy in neurological patients [18].

Relaxation techniques such as breathing or progressive muscle relaxation are therapeutic procedures used in various healthcare settings to treat patients experiencing high levels of affective distress, anxiety, depression, and pain [19]. As in the case of anxiety, perceived personal control, together with other variables like attribution, expectations, personal beliefs, self-efficacy, attention, problem-solving style, coping strategies, and imagery, have a significant influence on the perceived intensity, quality, and duration of pain [20]. Combined interventions using cognitive and behavioral approaches offer the best results in perceiving the pain while also improving the daily living of patients. Mindfulness practices and cognitive behavioral therapy (CBT) interventions are proven to be effective in pain management [21].

Virtual reality has become a useful and creative tool in the aforementioned regards. By creating immersive and interactive environments, VR transforms therapeutic exercises and mental health interventions into engaging and motivating activities. Studies show that VR in physical rehabilitation can bring functional improvement of more than 35% and increase motivation by more than 20% compared to classic rehabilitation [22]. The potential of using VR in rehabilitation has also reached commercialization level, proven by the Mindmaze system, successfully used in 19 countries and in over 100 000 rehabilitation sessions [1]. For individuals experiencing anxiety and panic attacks, VR can provide exposure therapy, which has proven itself to be very effective [23] in a controlled virtual environment, allowing patients to confront their fears and anxieties in a safe space. This experience, characterized by personalized immersion, offers patients an array of neurorehabilitation-oriented exercises, aimed at improving their mental health. For chronic pain management, VR has been shown to significantly reduce pain perception by means of distraction in a therapeutic setting. Patients can participate in guided meditation and visualization exercises that promote relaxation and pain relief. Moreover, VR-based therapy can be conducted remotely, thus integrating into our therapies the extremely important factor of accessibility. This combination of immersion, engagement, and personalization makes VR an essential tool in modern therapy, offering hope and improved outcomes for individuals dealing with anxiety, panic attacks, and chronic pain. Virtual reality (VR) can prove successful for pain management as well. Neurosurgical studies using virtual reality [24] show its potential in reducing anxiety and depression and improving pain management for patients suffering from chronic back pain. The Harvard MedTech Vx Pain Relief Program was used for 3 months as an at-home treatment, including various virtual reality environments with different goals: educational (courses explaining the patient’s condition), guided meditation, immersive distractions, or experiential entertainment (e.g., interactive paragliding). The results show that, on average, pain was reduced by 33% and anxiety by 46%. VR can thus provide a great alternative for pain management, avoiding opioid use, and allowing for at-home treatment, better accessibility, and the same, if not better, efficiency. Pain management is studied intensively by the University of Pittsburgh, and their system, Painimation, uses various types of abstract animations to represent pain [25]. It comes as an alternative to unidimensional pain assessment scales, allowing for qualitative and quantitative representations of pain through varied characteristics of animations (e.g., speed, visuals, colors). The project was developed using a human-centered design process meant to solve the pain communication issue—the incapacity of patients to express and visualize their pain correctly when interacting with the clinician and going through therapy. Such an approach combined with virtual reality would create a comprehensive, flexible system of pain management, suitable for chronic pain.

Serious games can prove to be a valuable addition to the rehabilitation process, in both VR and non-VR settings. Mechanics such as tasks, progress tracking, score, levels of difficulty, multiplayer options, powerups, hints, feedback, and precision evaluation are just some of the gamification aspects that can help the rehabilitation, especially in influencing the motivation and emotional involvement of the participants. Various studies include competition for neurorehabilitation, in games such as Pong arcade or sports (boxing, paddling, tennis), and show that the desire to become better than the other participants can lead to better performance of the rehabilitation tasks and higher motivation and enjoyment, especially when performed in a telemedicine program [26]. On the other hand, collaboration might be the more suitable approach for people requiring rehabilitation, with motivation being increased by the desire to be better together, socialize, and accomplish peers’ expectations [27]. The immense opportunities of serious games in rehabilitation also come from their diversity, including different genres (action, adventure, simulations, puzzle), and different purposes (sports, fantasy/pure entertainment, reproducing daily activities).

Our paper presents the potential offered by VR-based training tools and serious games for physical and psychological rehabilitation, validated in a clinical study with 25 patients. Our extensive and exploratory research proposes an integrative and innovative treatment procedure, not only by modeling classical rehabilitation procedures in the VR dimension but also by designing a clinical approach that alternates physical exercises with specific and focused anxiety reduction sequences. All the motor or psychological exercises we have designed for this protocol intervention are built around the purpose of increasing the perceived sense of control the patient is experiencing during the process of rehabilitation. Every patient benefited from consistent feedback from the research team and from adjustment in choosing exercise or level of difficulty in order to increase comfort and sense of control.

Section 2 will describe the materials and methods used, including the objectives of the study, details about the participants, and our system used in the testing procedure, as well as the study protocol. Section 3 presents the results collected during the 2-week tests performed in a clinical setting, as well as their statistical analysis. Finally, Section 4 presents the discussions of the aforementioned results, while Section 5 draws the final conclusions and mentions possible future directions of research and development.

2. Materials and Methods

2.1. Objectives of the Study

The aim of this study is to investigate and test the potential of virtual reality-based physical and psychological rehabilitation in patients with neuromotor or musculoskeletal conditions. The main goals of the system thus become social ones: improving the quality of life of patients, relieving the burden on the medical system, and increasing sustainability.

The main objective is to investigate the usefulness and perception of patients on the use of virtual reality in the recovery process.

Secondary objectives include the following:

• Evaluation of the performance and accuracy of exercises performed in virtual reality by patients;
• Evaluation of integration of anxiety or pain management exercises in alternation with physical recovery exercises;
• Assessing the patients’ ease of accommodation to VR technologies and equipment;
• Observing the effect of the experiment on patients’ motivation;
• Reducing anxiety and increasing self-efficacy.

It is worth mentioning that the last two secondary objectives will not be the focus of the current paper; they are listed as part of the complete objectives of the clinical study.

2.2. Participants

Data collection was carried out from 25 patients, coming from two different contexts: patients hospitalized at the National Institute of Medical Expertise and Recovery of Working Capacity and patients suffering from musculoskeletal or neuromotor disorders but who are neither hospitalized nor constantly participating in rehabilitation sessions. The testing occurred between 22 July and 10 August 2024. As the testing protocol and VR exercises were focused on the upper part of the body, patients requiring rehabilitation only for the lower limb were not accepted as participants. Patients were enrolled through anamnesis and clinical exam, and for the study group, we included only those with one or more of the following disorders: various types of herniation, carpal tunnel syndrome, degenerative modifications of the spine, or musculoskeletal conditions caused by work or car accidents. Patients with psychiatric conditions, moderate or severe cognitive impairments, or those requiring palliative treatment were not included in the study. All patients were enrolled voluntarily and were first evaluated by the doctors collaborating with our team.

This study required patients to respect certain criteria and not be affected by certain conditions, especially related to cognitive capacity. Detailed inclusion and exclusion criteria can be observed in

Table 1. Inclusion and exclusion criteria of the participants of the study.

Inclusion Criteria	Exclusion Criteria
Adults (18 years old minimum)	Psychiatric conditions associated with cognitive or personality disorders (e.g., schizophrenia, bipolar disorder, manic disorder)
Diagnosis of chronic neuromotor or musculoskeletal condition	Neurological conditions associated with moderate or severe cognitive impairment (e.g., vascular dementia, Alzheimer’s disease, aphasias)
Written informed consent	Severe conditions requiring palliative treatment
	Patients not meeting the inclusion criteria

below.

Participation was completely voluntary, and all participants signed their written consent and GDPR form (available in the Supplementary Materials). All personal data collected from the patients were pseudonymized in all scientific reports and analyses in order to make the identification of the participants not possible from the scientific publications. The demographic characteristics of the 25 participants are presented in

Table 2. Demographic characteristics of the 25 participants of the study.

Criteria	Characteristics	Number	Percentage (%)
gender	female	20	80%
	male	5	20%
residence	urban	19	76%
	rural	6	24%
age group	18–35	1	4%
	36–50	13	52%
	51–65	11	44%
education	primary education (max middle school)	2	8%
	secondary education (high school and eventually post-secondary non-tertiary education) higher education	14	56%
		9	36%
employment status	employed	15	60%
	retired	10	40%

below. Classification of the age groups did not follow habitual groups mentioned by the World Health Organization but has rather been carried out according to consumers’ practices and ways of interacting with technologies. We thus wanted to analyze if the results of the study were influenced by the patients’ familiarity with technology, and therefore, the age groups included millennials, working adults, and retired individuals.

Other information collected from the participants that was proven to be relevant to our study was related to their medical conditions, physiotherapy involvement, and technology experience. The patients’ conditions were evenly distributed between the two categories: neuromotor (52%—13 patients) and musculoskeletal (48%—12 patients) disorders. The most common neuromotor affections included various types of herniation (cervical, lumbar, dorsal), carpal tunnel syndrome, nerve damage, degenerative modifications of the spine, and cervicogenic syndrome, while musculoskeletal ones included scapulohumeral periarthritis (because of lifting/taking care of elders), arm and forearm polytrauma, ulnar, clavicle or radial fractures (car or work accidents), cervical spondylitis, fibromyalgia, scoliosis, osteoporosis, rheumatoid arthritis, lumbar discopathy, or radiculopathy. Secondary disorders encountered were hypertension, vertigo, asthma, stenosis, osteoarthritis, psoriasis, tachycardia, diabetes, dyslipidemia, autoimmune thyroiditis, and ligament laxity, but also mental disorders such as attention deficit hyperactivity disorder (ADHD) or depression. The latter affected 20% of the patients involved in the study (5 patients). Regarding the frequency of physiotherapy sessions, most respondents (60%—15 patients) were performing more than 5 sessions per week, probably influenced by their hospitalized status in the medical recovery institute, while others (4%—1 patient) performed 3–4 sessions per week while the rest of them (36%—9 patients) performed 1 (20%—5 patients) or no rehabilitation sessions (16%—4 patients) in their chronic phase of the disorder.

In order to analyze any possible correlation between the obtained results from the tests and the patients’ previous experience with technology, we assessed their self-evaluation of technological experience, virtual reality experience, and preferred difficulty of games. Most respondents (52%—13 patients) mentioned they have a medium level of technological expertise (satisfactorily managing several devices and applications including laptops, smartwatches, and internet browsing), 36% (9 patients) have little experience (using just their mobile phone with various applications), and only 12% (3 patients) self-evaluated themselves as very experienced (efficiently managing various devices and applications—laptops, smartwatches, and internet browsing). Experience with VR had even lower scores, with most participants (60%—15 patients) considering themselves inexperienced (not knowing the meaning of it/never tried it), 24% (6 patients) had low experience (tested VR at least once), and 16% (4 patients) had medium experience (used multiple applications in virtual reality). None of the participants were very experienced in the VR area. When asked about the preferred level of difficulty of games, on a scale from 1 (very easy) to 5 (very difficult), the average score obtained was 3.56 with the highest percentage (40%—10 patients) preferring a medium difficulty level (rated 3).

2.3. System Description

The entire system used in the clinical trials is focused around the Unity software application (version 2022.3.26f1), which is built to run on the VR headset. Additional elements include data collection of pulse and oxygen levels and real-time monitoring by the therapists or testing team of the exercises performed by the patient. The overview of the entire system can be observed in Figure 1, while software and hardware components are described in the following sections.

2.3.1. Software Components

The software part of the system consists of various virtual reality exercises developed using the Unity 3D game engine. The exercises are divided into two main categories, based on their purpose: physical rehabilitation and psychological rehabilitation. The two categories can be used separately for therapy or alternatively in a complex and complete physical and mental rehabilitation procedure. The game design of the exercises was created together with medical specialists and psychologists from our team, while changes to the mechanics or to the player’s experience were implemented based on feedback from the collaborating medical institutions and from the patients involved in the clinical study. For the physical exercises, our goal was to create easy-to-play exercises, with intuitive gameplay, suitable for people suffering from affections of the upper body (spine or upper limb). The system includes a wide variety of exercises: throwing a ball to hit cans, directing a ball on an inclined plane to reach some targets, whack-a-mole, boxing, and collecting fruits. Only the last three physical games were used in the clinical trials, as they were evaluated as the most suitable by the medical professionals for the respective patients. For the mental rehabilitation exercises, advice from psychologists led to the creation of relaxation and mindfulness exercises suitable for treating anxiety and helping the rehabilitation process become more effective and less burdensome.

The design process of the games had in mind the possibility of personalization based on the patient’s medical state. For instance, the boxing game can be suitable for spinal cord issues that require full stretching of the arms, while fruit collection focuses more on improving fine motor skills. Personalization is possible according to the degree of the affection or associated conditions; thus, the games include various levels of difficulty and different skins or focus on different muscular groups (e.g., in the progressive muscle relaxation).

We will further describe each one of the exercises used in the clinical trials, focusing on their purpose, medical suitability, functionalities, and gamification principles. An overview of the exercises can be seen in

Table 3. Overview of the exercises included in the clinical study.

Exercise	Health Condition	Movements	Game Mechanics
Whack-a-mole	Affections of spinal cord, musculoskeletal conditions	Both upper limbs, movement of arm and hand	Score, time, levels of difficulty, enemies, accuracy
Boxing	Affections of spinal cord, musculoskeletal conditions	Both upper limbs, ample movements of arm	Score, time, targets
Fruit collection	Carpal tunnel syndrome, affected fine motor skills	Fine hand movements, both hands, all fingers	Score, time, accuracy
Breathing	Anxiety, panic attacks, stress	Chest movements, inhaling and exhaling	Time, repetitions, skins
Progressive muscle relaxation	Anxiety, panic attacks, stress	All upper body, contraction and relaxation of muscle groups	Time, repetitions, skins

below, including the main targeted health conditions, involved movements, and game mechanics.

Physical Rehabilitation Exercises

The implementation of all physical exercises was optimized so that they are suitable for space constraints and can be easily performed in a clinical setting. This optimization came with the cost of some patients wanting more space and liberty of movement, especially in the boxing scene. Each game has written instructions and scores displayed in the graphical interface, as well as appropriate audio cues.

Whack-a-mole is a very popular theme park game where the player is facing a machine comprising nine empty spaces from which mole-resembling objects come out, with the purpose of them being hit with rubber hammers wielded by the player (Figure 2). The number of points earned by the user is determined by the number of moles that they have pushed back with the hammer. The VR representation of this game is true to its real counterpart, as ensured by the employment of realistic 3D models, which help create an immersive virtual environment. On top of that, aiming to ensure ease of usage, the toy hammers are already attached in-game to the hands of the user, which allows for the player’s full focus to rest on the purpose of the exercise: to hit as many moles as possible. Dual, as well as single wielding is implemented, in order to provide a personalized and effective therapeutic experience to all users, mainly aimed at patients treating fine motor skill impairments and allowing therapy for right, left, or both hands. The game incorporates three difficulty levels, easy, medium, and hard, visible in the game by the apparition incidence of the moles, as well as by the time that they remain active within the empty spaces before retracting, should the user not hit them. The utility of this mechanic is encouraging the player to increase the difficulty of their therapy sessions, as monitored by the in-game measurement of the user’s accuracy level and total score, a very important factor in ascertaining the efficacy of the method.

The boxing exercise encompassed in this system aims to recreate the training process of the eponymous sport, with the player being spawned in a room with a trainer as a non-playable character and three boxing sacks. This therapy model was created to help in treating upper limb mobility issues and mild spinal cord damage, with the patient being required to stretch their arms and back in order to hit targets that appear at progressively greater heights upon the boxing sacks (Figure 3a). The main level of this exercise can be completed by successfully aiming at the desired spots on each sack with a total of three spawning within the game area. These spots are depicted by small, floating glowing targets that the users can hit multiple times per height level, with each blow being counted toward the final score. If this phase of the game was completed, it means that the player has succeeded in the base physical therapy and is presented with other levels, with the targets now spawning on the right-hand and left-hand side boxing sacks of the scene, with respect to the same height-progression mechanic which is employed on the main level of the exercise. The patient may then continue the game until the time designated for the session expires, after which the extent of their upper limb physical ability and spinal cord mobility can be deduced, based on the number of levels completed, as well as their individual completion levels.

Another immersive and useful gamification of a real-life activity is the rendition of fruit collection within the therapy virtual environment, which merges immersion with tranquil interactivity by providing users with an organic, simple experience. The user is spawned in a scene depicting an orchard and is surrounded by a semi-circular tabletop, upon which a basket is placed. At the beginning of the game, a carrot model is also found near the basket, with the player being allowed to experiment with the pinch mechanic required for manipulating the fruits and vegetables. This exercise is mainly aimed to be used by people suffering or recovering from carpal tunnel syndrome, with dual wield being implemented to best cater to patient needs. The main mechanic of this exercise is the downward spawning of fruits in the user environment and on the tabletop, but not exclusive to the current field of view, with the purpose of being found and gathered by the player and deposited into the basket (Figure 3b). The hand gesture required for grasping the fruit is a three-digit pinch motion, which can prove difficult for patients suffering from the aforementioned syndrome, while at the same time representing good practice in regaining full motion control of the hands and wrists. With the same purpose of measuring efficacy, a score and a precision percentage are calculated and displayed at the end of the therapy session.

Mental Rehabilitation Exercises

Mental exercises have mostly relaxation and anxiety reduction purposes. They do not include scores or levels of difficulty, being strategically alternated with physical exercises in the clinical trial procedure.

Breathing exercises represent a popular mindfulness technique employed today in managing not only anxiety but also in keeping regular stress levels under control and preventing panic attacks. They are usually represented by a mostly audio-guided meditation process, with the therapist providing instructions on the length of each respiratory phase, as well as on the number of repetitions and intermissions. Guided imagery is usually associated with this type of exercise, with a tranquil environment having a central object in the middle being one of the most common representations. For instance, a central sphere contracts and dilates with respect to the instructions given by the therapist for each step of the exercise. A VR rendition of this type of therapy is reminiscent of its real-life counterpart, with the user being spawned in a celestial environment, having a sphere as their frontal focus (Figure 4). The calming musical background ensures the creation of an immersive scene, doubled by a step-by-step audio guide that introduces the user to the rules and the steps of the process throughout the entire session. A usual exercise within this type of therapy which a patient can access in a virtual environment comprises 2-second-long intervals divided between instructions to inhale, exhale, or hold, as well as small rest intervals in between repetitions. At the end of the session, the user is thanked for their preoccupation with psychological self-care and is encouraged to access the therapy as many times as they find helpful in the future.

Progressive muscle relaxation (PMR) is a reputable exercise proven useful in controlling anxiety, reducing stress, and even countering sleep paralysis effects. The exercise bases itself on the user slowly tensing and relaxing all the muscles in their body, from their anatomical extremities towards their core, functioning upon the theory that one cannot be both relaxed and stressed at the same time, thus aiming to eliminate anxiety symptoms. The scene in which the subject performs the training portrays a 3D model in the middle of it, an anthropomorphic avatar having the purpose of mirroring and exemplifying what the user must do in order to complete the exercise (Figure 5). A ball of light traverses the avatar’s body, symbolizing the body part on which the PMR focuses on each level, thus adding a visual facet to the user’s experience. Normally, the exercise begins with the user having to curl their toes and fingers and progresses to tensing and relaxing muscles further up in the body until the game ends. As the games were adapted to the testing protocol, the PMR section included in the testing protocol only focuses on the upper part of the body. A calm voice guides the user throughout the entire exercise, offering symbolic commendation and encouraging sounds each time the level is completed.

2.3.2. Hardware Components

The necessary hardware components for ensuring the proper functioning of the system include a virtual reality headset with controllers or hand tracking, a device for pulse-oximetry, and, optionally, a laptop or mobile device for supervising in real time the exercises performed by the patient.

For increased accessibility and affordability, the chosen headset was Meta Quest 2, needed for rendering the application in VR, as well as its respective hand-tracking capabilities, crucial in capturing user hand motion and interaction which were necessary for quantifying the accuracy of the exercises. Integrating these into the setup allowed for immersive interaction, real-time data capture, and professional monitoring, thus enhancing the user experience and facilitating accurate measurements. Hand tracking was therefore preferred for easier handling, yet the exercises are created to function with the Meta controllers as well, if the patients request it or if there are any technical issues with the hand-tracking process.

Additionally, an O2 ring pulse oximeter was incorporated for measuring the patient’s breathing and relaxation techniques’ effectiveness, as well as the level of stress or fatigue from the physical exercises. This approach enabled the assessment of the efficacy of the meditation games in the form of their ability to reduce tachycardia associated with high levels of anxiety and panic attacks.

2.3.3. Validation with Healthy Individuals

Before the testing of the system with patients, the safety of use was analyzed with the development team as well as with a significant number of healthy individuals. A total of 62 participants from diverse backgrounds and different age groups completed a research survey and tested the system’s prototype, offering comprehensive insights and valuable information regarding the participants’ anxiety levels, pain management strategies, previous rehabilitation experiences, and their openness to using VR for therapeutic purposes. The diversity of people’s age groups, occupations, and technological and VR expertise, as well as previous physiotherapy and psychological experiences, provided a rich, valuable, and truthful dataset that reflects a wide range of backgrounds and perspectives, enabling us to design a VR application that meets the needs of a broad and generalized user base.

We have thus gained valuable insights into the specific requirements and expectations of users, which are essential for ensuring the creation and optimization of a practical and user-friendly application. By understanding healthy users’ needs and preferences, we were able to validate the safety of use and tailor the application to provide effective and engaging therapeutic experiences, all while relying on VR to transpose these qualities in an immersive environment.

2.4. Study Protocol

After ensuring the safety of use of the system with healthy individuals, tests with patients in a clinical setting could be performed. Most of the patients involved in our study were following a 2-week rehabilitation process including classical physiotherapy sessions. The VR exercises were added to their routine and performed daily for a week at the end of the classical procedures.

2.4.1. Description

Before the actual sessions, specific equipment and configurations were required:

• A virtual reality headset (Meta Quest 2) including a pre-installed AdaptRehabVR application (current software system presented) with hand tracking and (optionally) controllers;
• Guardian scanning (the space where the activity is carried out in the virtual environment)—it can be stationary (a circle with a diameter of approx. 1 m around the chair on which the patient is seated) or room-scale (a play area of minimum 2 m × 2 m, allowing the user more freedom of movement);
• Pulse oximeter O2 ring, monitoring the user’s heart rate and oxygen level on the ViHealth app installed on the therapist’s mobile phone;
• (optional) Laptop/mobile phone for real-time tracking of exercises performed by the patient using the Meta Horizon application and casting capabilities.

During the actual experiment, the following steps were carried out, in the place established by mutual agreement with the medical staff (clinic, hospital, the patient’s home). All the steps are performed by the patient in a sitting position and using a stationary boundary requiring a space of a circle with 1 m diameter, in order to minimize the risks of motion sickness and avoid restrictions related to limited space:

• Listening to the indications and details about the project and how the experiment will be conducted;
• Completing and signing the informed consent and GDPR agreement; the informed consent describes the project in detail and the implications and rights of the user, as well as possible risks and side effects, while the GDPR agreement mentions how the users’ data will be used;
• Completing the demographic questionnaire (demographic questions, state of health questions, and self-evaluation of technological experience);
• Completing the initial self-efficacy and affective distress questionnaires;
• Accommodation with the virtual reality headset and the environment, including explanations of the games;
• Carrying out the tasks corresponding to the test protocol in virtual reality, as follows:
  • Physical recovery exercise “Whack-a-mole”—1 min;
  • Deep breathing exercise—1 min;
  • Relaxation (relaxing music)—30 s;
  • Physical recovery exercise “Boxing” or “Fruit picking”—1 min;
  • Progressive muscle relaxation exercise—1 min.
• Completing the general feedback questionnaire;
• Completing the final self-efficacy and affective distress questionnaires.

As an observation, steps 1–5 were performed only during the first session, and step 6 was repeated daily, while steps 7–8 were performed only on the last day of the clinical trial. The suitable exercise to perform with each patient between boxing and collecting fruits was chosen based on the strict indications of the physiotherapists supervising the clinical tests, according to the affections of each patient, and was kept until the end of the clinical trial. Boxing was preferred for shoulder affections, while collecting fruits was suitable for improving fine motor capacities of the wrist or various neuropathies. Constant improvements were brought to the exercises based on the users’ feedback, including the addition of more difficulty options, real-time feedback, and audio cues.

This section presents the entire study protocol, as it was discussed with medical professionals and agreed upon by the ethics committee of the medical institution involved in the clinical study. All procedures and tests comply with the ethical standards in the Helsinki Declaration of 1975, as revised in 2008(5).

2.4.2. Instruments

The instruments used for gathering insightful results included both objective and subjective tools, in order to ensure a comprehensive understanding of the physiological and psychological results collected from the patients. They will be further described based on their corresponding category.

Objective Tools—Demographics, Physicians’ Evaluation, Scores, and Other In-Game Data

Objective tools included the collection of demographic data (age group, gender, residence, education, and occupation) as well as the physicians’ evaluation, including a category for the affection (neuromotor, musculoskeletal, other), diagnostics, associated affections, and frequency of performing rehabilitation sessions.

Another objective tool is represented by in-game data which are automatically collected by the system. This includes accuracy and number of moles hit in a certain level of difficulty (whack-a-mole), score, sublevel, and position of the last punching bag reached (boxing), accuracy, and number of fruits collected (collecting fruits game). The O2 pulse-oximetry ring collected the pulse and oxygen saturation values during the entire testing session, providing, with the help of the associated ViHealth mobile application, additional information such as charts of the evolution of the heart rate, oxygen saturation or motion over time, average values of the heart rate and oxygen level, duration of the recording, and eventual drops in the saturation, as well as distributions of oxygen levels and heart rate ranges.

Subjective Tools—Questionnaires and Mental Assessment

Subjective tools included various questionnaires filled in by the patients based on their self-assessment. These include initial evaluation questionnaires, final feedback questionnaires, and mental assessment self-report instruments (see Supplementary Materials).

Initial evaluation questionnaires required users to self-assess various competencies such as the following:

• Technological experience level:

  ○

  Inexperienced (not using technology);

  ○

  Little experience (using just their mobile phone with various applications);

  ○

  Medium experience (satisfactorily managing several devices and applications, including laptops, smartwatches, and internet browsing);

  ○

  Very experienced (efficiently managing various devices and applications, including laptops, smartwatches, and internet browsing).

• Experience with virtual reality:

  ○

  Inexperienced (not knowing the meaning of it/never tried it);

  ○

  Low experience (tested VR at least once);

  ○

  Medium experience (used multiple applications in VR);

  ○

  Very experienced (used various applications in VR in an efficient way).

• Preferred level of difficulty of games—scale from 1 (very easy) to 5 (very difficult).

The final feedback questionnaire required users to evaluate the following aspects related to the games and their personal experience during the tests:

• Enjoyment, ease of use, motivation, relaxation for whack-a-mole, boxing/collecting fruits, breathing, progressive muscle relaxation, on a scale from 1 (not at all) to 5 (very much);
• Usefulness for anxiety/panic attack management for breathing and progressive muscle relaxation, on a scale from 1 (not at all) to 5 (very much);
• Comfort of testing the exercises in virtual reality, on a scale from 1 (uncomfortable) to 5 (very comfortable);
• Justifications for any score less than 3 in the previous questions;
• If they would use the proposed system at home, in a telemedicine program (yes/no/do not know);
• Other suggestions for improvement/future development.

The clinical psychological instruments we have used in this research are standardized and calibrated for the Romanian population and are part of a large kit of psychological assessments largely used in Romania and produced by Romanian Psychological Testing Services Cluj-Napoca since 2007.

The Self-Efficacy Scale (SES) is a self-assessment instrument that reveals the individual’s belief about personal resources involved in managing difficult situations across their lifespan. The self-efficacy concept is not a new one, but an extensively studied one over time since the validation of Albert Bandura’s social–cognitive theory of personality [28]. As self-efficacy expectations in a particular task influence the individual’s thoughts, emotions, and behaviors, they have an important role in sizing the performance associated with the task. In our study, we referred to self-efficacy in personal and professional contexts, guiding the patients to evaluate the impact of the disease onset over their personal and professional activities. Results from various studies revealed that self-efficacy negatively correlates with anxiety (the higher the level of anxiety, the lower the level of self-efficacy, and vice versa) [29]. The ten-item scale ranges for the answers from 1 to 4 where 1 means ”completely untrue as far as I’m concerned” and 4 means ”perfectly true as far as I am concerned”, offering a total score of self-efficacy between 10 and 40 points. The higher the score, the higher the levels of self-efficacy.

The affective distress profile (ADP) is a 39-item scale measuring functional and dysfunctional negative emotions like worry/anxiety or sadness/depression, but also positive emotions [30]. The scale is based on the binary model of distress of Albert Ellis [31] which divides negative or positive emotions into functional or dysfunctional categories. Functional emotions (positive or negative) contribute to or facilitate the achievement of the individuals’ goals while dysfunctional ones (positive or negative) block the individuals’ actions or achievements. There are several scores that can be calculated: an overall distress score, a negative emotion score, and a positive emotion score, as well as separate scores for “worry” (functional), “anxiety” (dysfunctional), “sadness” (functional), and “depression” (dysfunctional). The cognitive-behavioral theories assume an intricate relationship between cognition, emotions, and behaviors. Interventions for reducing anxiety aim at the cognitive and physiological pillars of the approach. A similarly complex and composite structure is present in the self-efficacy concept. In the framework of CBT, addressing the cognitive and the physiological vectors in perceiving a situation will influence the emotional balance and the appropriate behavior a person could experience. Considering the emotional vector in a medical condition is an important aspect of our integrative approach to neurorehabilitation. Therefore, together with objective and subjective measures, open real-time observations from the team assisting the patients during their tests were collected.

Data Collection

The study group of 25 patients was divided into groups based on various categorical variables: technological experience (T1, T2, T3), previous exposure/experience with VR (V0, V1, V2), or preference for the game difficulty (G1–G5)—

Table 4. Statistics related to the criteria used for dividing patients into subgroups.

Criteria	Characteristics	Number	Percentage (%)
Technological experience	Little experience (T1)	9	36%
	Medium experience (T2)	13	52%
	Very experienced (T3)	3	12%
VR experience	Inexperienced (V0)	15	60%
	Little experience (V1)	6	24%
	Medium experience (V2)	4	16%
Preferred difficulty of games	Very easy (G1)	1	4%
	Easy (G2)	2	8%
	Medium (G3)	10	40%
	Hard (G4)	6	24%
	Very hard (G5)	6	24%

. For the simplicity of the statistical analysis, the subgroups were labeled as follows: 0—inexperienced; 1—little experience; 2—medium experience; and 3—very experienced. There were no users who assessed themselves as inexperienced with technology (T0 with 0 users) and no users very experienced with VR (V3 with 0 users).

One of the patients experienced serious dizziness unrelated to virtual reality, so they performed a simplified testing procedure and did not complete the final feedback questionnaires, thus resulting in 24 valid entries for the batch of data. In total, 13 of the patients performed the collecting fruit game, while 11 participated in boxing, according to the therapists’ recommendations. Everyone performed the whack-a-mole exercise.

The chosen variables that are analyzed in correlation with the previous groups are heart rate, oxygen level, score accuracy over all types of games, ease of use and relaxation of all games, and openness to using the system in a telemedicine program.

3. Results

Data were collected and analysis was performed using SPSS 26.0. Statistical significance was considered for a p-value < 0.05. The correlation between various subgroups and quantitative dependent variables such as scores, exercise feedback (ease of use and relaxation), heart rate, or oxygen saturation will be further analyzed using appropriate statistical tools.

Table 5. Descriptive statistics of objective and subjective data collected for statistical correlations.

Data Collected	Mean	Median	Variance	Std. Deviation	Min	Max	Range	Skewness	Kurtosis
O2 (%)	96.36	97	1.323	1.15	94	98	4	−0.609	−0.378
Heart rate (beats/min)	76.32	76	81.893	9.049	62	98	36	0.422	−0.143
Whack-a-mole (ease of use) 1–5 scale	3.62	4	1.423	1.193	1	5	4	−0.844	0.509
Whack-a-mole (relaxation) 1–5 scale	4.5	5	1.043	1.022	1	5	4	−2.269	5.199
Boxing (ease of use) 1–5 scale	4.64	5	0.455	0.674	3	5	2	−1.8	2.611
Boxing (relaxation) 1–5 scale	4.45	5	1.473	1.214	1	5	4	−2.743	7.939
Collecting fruits (ease of use) 1–5 scale	3.62	4	1.423	1.193	1	5	4	−0.844	0.509
Collecting fruits (relaxation) 1–5 scale	4.46	5	0.936	0.967	2	5	3	−1.831	2.704
Breathing (ease of use) 1–5 scale	4.79	5	0.259	0.509	3	5	2	−2.539	6.258
Breathing (relaxation) 1–5 scale	4.96	5	0.042	0.204	4	5	1	−4.899	24
PMR (ease of use) 1–5 scale	4.63	5	0.505	0.711	3	5	2	−1.671	1.368
PMR (relaxation) 1–5 scale	4.46	5	1.303	1.141	1	5	4	−2.569	6.142
Comfort in VR 1–5 scale	4.44	5	1.173	1.083	1	5	4	−3.147	11.933
Would you use the system in a telemedicine program? (0—No; 1—Yes)	0.88	1	0.11	0.332	0	1	1	−2.491	4.563
Whack-a-mole average score	68.877	71.333	309.312	17.587	20	100	80	−0.98	1.512
Boxing average score	160.785	122	11,074.5	105.235	61	350	289	1.105	−0.204
Collecting fruit average score	63.333	65.25	252.587	15.893	35.5	91.5	56	−0.119	−0.469

includes descriptive statistics of these quantitative dependent variables, and their analyses will be further described in the following paragraphs.

Normality assessment was performed to check the values’ distribution of the following variables: the comfort of testing in VR, the average level of heart rate and average oxygen saturation during the training process, ease of use and relaxation for whack-a-mole, boxing, and collecting fruits, breathing, and PMR games. Kolmogorov–Smirnov and Shapiro–Wilk (SW) tests were performed, with the preference for the Shapiro–Wilk results for our rather small batch of patients. Normal distribution was considered for a p > 0.05 of the SW test. The results show that the only variable normally distributed was the average heart rate, as observed in the histogram (Figure 6a) and Q-Q plot (Figure 6b) below, obtaining p = 0.759 in the Shapiro–Wilk test.

Interestingly, although oxygen saturation was not normally distributed over the entire batch, when checking on subgroups related to technological experience, the result of the Shapiro–Wilk test showed normal distribution for all three categories (T1 p = 0.102, T2 p = 0.055, T3 p = 0.637). The boxplot in Figure 7 shows the distribution of average oxygen saturation levels for the three subgroups of patients divided based on technological experience.

According to the non-normal distribution of most values mentioned beforehand, an ANOVA is only suitable for correlation analysis between the pulse and various subgroups of patients, or oxygen saturation and the same subgroups, respectively. We therefore applied the Kruskal–Wallis (KW) analysis in order to assess the possible correlation of the other variables and patient subgroups. The following subsections will focus on the statistical analysis of various objective and subjective collected data.

3.1. Objective Collected Data—Statistical Analysis

3.1.1. Heart Rate and Oxygen Saturation

Oxygen and heart rate values collected show the effort and stress levels of the participants during the tests. The charts in Figure 8 show the evolution of the heart rate, oxygen saturation, and motion of a patient during the five minutes of the testing procedure, with pulse rate and motion peaks during the first minute (whack-a-mole) and third minute (collecting fruits). The information recorded in the pulse and motion charts shows the clear differences between the physical activity and the relaxation exercises (Figure 8a). The final motion inputs observed on the chart are explained by the PMR gestures of the respective hand or by the movement of the patient’s hand when removing the VR headset to end the testing process. The pulse rate range and distribution (74–88 beats/min), as well as its average (80 beats/min), show that the patient was not stressed during the entire procedure (Figure 8b).

For statistical analysis, three sets of ANOVA tests were conducted in order to find correlations between average heart rate or oxygen saturation and the aforementioned subgroups of patients, divided based on technological experience, VR experience, and preferred level of difficulty for games.

The results did not prove statistical significance in the correlations related to the technological experience (p = 0.767 for heart rate, p = 0.226 for oxygen saturation) or preferred level of difficulty (p = 0.824, p = 0.113), which might imply that the levels of stress and effort of patients were not related to their technological savviness or previous gaming experience. Interestingly, results related to the correlations with VR experience were lower (p = 0.174 for heart rate, p = 0.140 for oxygen saturation), and further investigations on a higher number of patients are necessary to understand a possible influence of VR on the stress and effort of patients measured through physiological parameters.

3.1.2. Games Scores

In order to find any correlations between performance and the subgroups of patients, Kruskal–Wallis tests were performed. The game scores were calculated as averages across all trials performed by a person, for the three physical rehabilitation exercises: whack-a-mole, boxing, and collecting fruits. The same subgroups were analyzed as before, including technological experience, VR experience, and preferred level of difficulty for games.

The results show that the distribution of the whack-a-mole score average is different across various subgroups based on the level of experience with technology of the users (p = 0.04)—Figure 9. Pairwise comparisons of the whack-a-mole average score by type of technological experience showed statistically significant differences between patients with low levels (T1) of experience and those with high levels (T3) of experience (p = 0.023), borderline significance between low (T1) and medium (T2) levels of experience (p = 0.057), and no significance between medium (T2) and high (T3) levels (p = 0.28).

Regarding the correlation of the games’ scores and other criteria for dividing patients (levels of experience with VR, preference for the difficulty of games)—Figure 10a,b—KW analysis displayed no significant differences, showing that performance in the physical rehabilitation games is not dependent on previous VR experience or gaming preferences.

3.2. Subjective Collected Data—Statistical Analysis

All the subjective data collected through user feedback questionnaires were not normally distributed; therefore, Kruskal–Wallis analyses were performed on the various subgroups of patients, created based on technological experience, VR experience, and preferred level of difficulty for games.

Regarding the correlation of the ease of use or relaxation levels for subgroups of people with different technological experiences, the only game that showed statistically relevant differences in the distribution was the breathing exercise. Technological experience showed a significant influence (p = 0.03) on how users perceived relaxation during the breathing scene and borderline influence (p = 0.057) on the ease of use of the same scene. Pairwise comparison showed statistically significant differences between patients with a high level of technological experience (T3) and those with a low level (T1) (p = 0.016), as well as between patients with a high level of technological experience (T3) and those with a medium level (T2) (p = 0.011). There were no significant differences between low (T1) and medium (T2) levels of technological experience (p = 0.9) related to the perception of relaxation in the breathing scene. The other exercises recorded no significantly relevant differences across different technology-savvy patients.

Correlations based on subgroups of people with different virtual reality experiences showed even more interesting results, with more criteria proving to be significantly influenced by these categories. After seeing the whack-a-mole scores influenced by the technological experience, we can once again see that the user perceived the relaxation of this game to be significantly influenced by their VR experience (p = 0.033), and the ease of use was borderline significant (p = 0.069). Pairwise comparison showed significantly relevant correlations between little VR experience (V1) and no experience (V0) (p = 0.021), as well as between little (V1) and medium (V2) experience (p = 0.024). PMR was also significantly correlated with the VR experience (p = 0.002), with a pairwise comparison showing significantly relevant correlations between little (V1) and medium (V2) VR experience (p = 0.037), as well as between little and no VR experience (p = 0.001).

When asked if they would use the proposed system at home, in a telemedicine program, a question which had the purpose of analyzing the confidence of the users in the VR system, the results were significantly correlated as well (p = 0.006). Only people with little VR experience (V1) showed reticence in the use of such a system at home, representing 12% of the total number of participants. Correlations for subgroups of people divided based on VR experience are presented in

Table 6. VR experience categories and pairwise comparisons (VR Cat—categories of VR experience; V0—inexperienced; V1—little experience; V2—medium experience).

Null Hypothesis			Test		Sig.
The distribution of whack-a-mole relaxation is the same across categories of the level of experience with VR.			Independent-Samples Kruskal–Wallis Test		0.033
The distribution of PMR is the same across categories of the level of experience with VR.			Independent-Samples Kruskal–Wallis Test		0.002
The distribution of user’s confidence to use such a system at home, in a telemedicine program, is the same across categories of the level of experience with VR.			Independent-Samples Kruskal–Wallis Test		0.006
Pairwise comparisons of VR Cat for PMR
Sample 1-Sample 2	Test Statistic	Std. Error	Std. Test Statistic	Sig.	Adj. Sig.a
V1-V2	−7.583	3.640	−2.083	0.037	0.112
V1-V0	9.548	2.752	3.470	0.001	0.002
V2-V0	1.964	3.197	0.614	0.539	1.000
Pairwise comparisons of VR Cat for user’s confidence in using the system in a telemedicine program
Sample 1-Sample 2	Test Statistic	Std. Error	Std. Test Statistic	Sig.	Adj. Sig.a
V1-V0	6.250	2.003	3.121	0.002	0.005
V1-V2	−6.250	2.676	−2.335	0.020	0.059
V0-V2	0.000	2.333	0.000	1.000	1.000
Pairwise comparisons of VR Cat for whack-a-mole relaxation
Sample 1-Sample 2	Test Statistic	Std. Error	Std. Test Statistic	Sig.	Adj. Sig.a
V1-V0	6.048	2.620	2.308	0.021	0.063
V1-V2	−7.833	3.466	−2.260	0.024	0.071
V0-V2	−1.786	3.044	−0.587	0.557	1.000

^a Significance values have been adjusted by the Bonferroni correction for multiple tests.

below.

The fact that the ease of use of all exercises was either statistically insignificant or maximum borderline significant in the case of whack-a-mole (p = 0.057) is encouraging, showing that the user experience and design of the exercises were appropriate and provided similar facility of use despite the user’s lack of VR experience or knowledge. Interestingly, VR comfort was not significantly correlated with VR experience after the KW test, as most users perceived the technology as comfortable regardless of their previous interactions with virtual reality, as observed in the boxplot below (Figure 11).

Finally, KW analyses showed no significant correlations between the preferred level of difficulty users have about games in general and the ease of use or relaxation perceived in the exercises of the testing protocol. This shows once more the appropriateness of the design and the fact that the flexibility of exercises (different levels of difficulty, different backgrounds, skins, etc.) made them suitable for a wide range of people, avoiding both boredom (when games are too easy) and frustration (when games are too difficult).

4. Discussion

Our study had the purpose of analyzing the effects of a testing protocol based on virtual reality for physical and psychological rehabilitation, conducted with 25 patients suffering from different musculoskeletal or neuromotor disorders. This study included two physiotherapy exercises and two relaxation exercises, alternated to create a 5 min training session. Both objective and subjective data were collected, and statistical analysis was performed to find relevant correlations.

One important result is the correlation between the whack-a-mole average score and the level of technological experience of the patients. The whack-a-mole exercise is the most advanced game in terms of mechanics, controls, and complexity, so the differences between the results of people with low or high technological savviness are justified, as people more accustomed to technology understand and adapt faster to technological challenges and more complex systems. The other games’ scores, boxing and collecting fruits, showed no correlation with the level of technological experience, as they are very simple to understand and complete by any user.

Similarly, as the whack-a-mole exercise is the most complex in terms of VR mechanics, requiring a good sense of depth perception (moles displayed in a 3 × 3 tridimensional matrix), as well as good coordination between the real hand recognized by the hand-tracking capabilities and the virtual hand with the hammer attached, correlation results between relaxation in this game and VR savviness show that the users with the most previous VR experience were able to stay the most relaxed and not perceive the tasks as stressful.

Another interesting aspect is related to the relaxation felt by people in the psychological exercises in correlation with their technological experience. In particular, the relaxation self-assessed by the patients in the breathing exercise was higher in the case of experienced users. This result, as well as the lack of significant differences between low and medium levels of technological experience, can refer to the fact that people with high technological expertise can better understand the potential of using technology assets for relaxation purposes and let themselves be more immersed in breathing exercises. The lack of other statistically significant correlations suggests that the ease of use and relaxation for physical rehabilitation games, as well as for progressive muscular relaxation techniques, can be perceived similarly by patients of all technological backgrounds based on the way the games’ user experience was planned (having in mind appropriateness independent of technological skills).

Progressive muscle relaxation was also clearly correlated with virtual reality savviness, which can be explained as PMR is an exercise showing an avatar facing the user, with a ball of light traversing various segments of the body. Patients must therefore associate the mirrored virtual character with their own real body and focus on the respective body part’s relaxation, actions which can be influenced and simplified by previous VR experiences.

Encouraging results were showcased after analyzing the responses related to patients’ openness to using such a system in a telemedicine program. All people with previous VR encounters were willing to use the exercises in future telemedicine rehabilitation. Low reticence from people inexperienced with VR can be influenced by the so-called fear of the unknown and can be solved by the accommodation acquired through multiple uses of virtual reality applications.

Our results showed that performance in physical rehabilitation games is not correlated with gaming difficulty preferences. Furthermore, ease of use and relaxation were perceived similarly by people from all groups (G1–G5). The ease of use was appreciated by all users, scoring an average of 4.26 across all games. This shows once more the appropriateness of the design and the fact that the flexibility of exercises (different levels of difficulty, different backgrounds, skins, etc.) made them suitable for a wide range of people, avoiding both boredom (when games are too easy) and frustration (when games are too difficult). It is interesting to further investigate our research results to analyze if motivation or enjoyment is correlated with game difficulty. Studies show that enjoyment increases if the difficulty matches their gaming experience [32].

Average heart rate levels (76.32 beats/min average across all users), as well as relaxation scores (with an average of 4.57 across all games), show that the levels of stress experienced by patients during the tests were low. This confirms results presented in previous studies, such as the one of Ho et al. [33], which highlighted that VR natural environments can show improvements in distress, depression, and anxiety. Further investigations are necessary to correlate our results from the psychological tests in order to see a clear evolution of the patients’ emotions over the VR experience.

Considering the results of our study, the recommendations for the practical use of this type of intervention deserve special mention. Home-based technologies are progressively used as an adjunct method in neuromotor rehabilitation plans [34]. The most important benefit of this type of approach is the increased autonomy and perceived control the patient is experiencing. A recent study has outlined the effectiveness of the home-based, self-administered VR intervention plan to reduce low back pain at a three-month distance after the completion of an eight-week treatment program, revealing a meaningful and enduring impact [35]. In our clinical study, the ease of use and the significant level of relaxation the patients have reported are encouraging results in the direction of using these types of technologies at home or in a less-guided rehabilitation setting. Our proposed exercises can be personalized and offer a high level of flexibility (different levels of difficulty or various backgrounds or skins), encouraging the patient’s involvement and increasing the familiarity and therefore the comfort and the motivation to pursue a demanding and resource-consuming set of exercises. Whether they are used in the hospital or at home, the correct use of this equipment requires minimum guidance from the medical personnel. In the first several sessions, the patient is encouraged to become familiar with the technical requirements and to let the self-management aspect of the equipment grow on them. Whether used at home with no supervision or in the hospital with minimum guidance, the results for every exercise could be stored for every patient in a personal database, offering an objective measure of the progress in the rehabilitation process. Not only can the progress be monitored, but so can the implementation of the therapist’s feedback regarding the number of repetitions or the accuracy of the execution for every exercise. Benefitting from a high level of immersion in a familiar (home-based) and comfortable environment (personalized settings in games) could improve the patient’s motivation and engagement and prevent incomplete exercises or even abandonment of the treatment plan. Patient adherence influences the completion of long-term rehabilitation plans and can be increased by the satisfaction gained in a gaming context [36].

There are some limitations of the study that could have influenced the results and discussions presented in the current paper. These research limitations are especially related to the sample size, demographics of the patients, and absence of long-term follow-up on the effectiveness of VR therapy. Therefore, as the clinical study was performed on 25 patients, the results regarding both objective and subjective tools could have been influenced by various demographic biases. Rehabilitation is needed worldwide by people of all genders and ages, yet the rather small batch of patients does not allow for gender-based or age-based comparisons (80% of test subjects were female, and 96% were in the 36–65 age group). Currently, various groups are underrepresented or unevenly distributed (no children or older people and no patients with zero technological experience or with high VR experience). Further investigations are essential in order to be able to draw clearer conclusions and confirm the obtained results presented in the current paper. These investigations should include further tests on a higher number of patients, diverse from a demographic point of view, in order to obtain a clear view of the true effects of VR for physical and psychological rehabilitation. In addition, our future investigations should include a significant number of representatives from the aforementioned underrepresented groups of people (in terms of technological and VR experience), in order to have a clear understanding of the influence of VR on functional improvement, motivation, and stress and effort ameliorations, regardless of technological expertise. As both physical and mental rehabilitation are long-term processes, future investigations should follow the progress recorded through the use of VR-based games in the long term.

5. Conclusions

Virtual reality provides us with the best tools to ensure perhaps the most important aspect of physical and psychological therapy: immersion. Its cutting-edge technologies, while ever-developing, have provided us with the necessary resources to not only create the scenes as we have pictured in our initial designs but to validate their potential with a set of patients, using a comprehensive and complex clinical protocol. Not all data mentioned in the Instruments subsection and not all goals from the Objectives of the study represented the focus of the current paper. We presented the complete protocol and the objectives chosen before the beginning of the clinical tests in order to give a complete picture of the potential of our system, clinical study, and results. In the current paper, we decided to put emphasis on the technical aspects of the research and on the objective data collected (game scores, heart rate, oxygen saturation), while briefly analyzing the subjective data dimension.

Virtual reality technologies can face various challenges, including skepticism, space limitations, or side effects (e.g., motion sickness). Correct recommendations for the practical use of a VR system as the one presented in our paper could overcome these limitations and bring the broader adoption of emergent technologies for rehabilitation closer. Skepticism of the patients can easily be overcome if their doctors are convinced and involved even in the design process of the system, as patients have natural confidence in the recommendations provided by their physicians. Impressively, patients were capable of adapting instantly to the VR environments regardless of their familiarity and previous experience in virtual reality, a fact which shows that game design and immersion play an essential role in the matter. Space limitations can be overcome by correctly designing the games so that they can be performed while seated or in a limited area. Finally, motion sickness is way less presented when seated and during short therapy sessions. To avoid any discomfort caused by the use of it, patients suffering from vertigo should only use virtual reality training if allowed by their therapists and for very short amounts of time.

As more studies show the positive effects of combined therapy including modern technologies and psychological training [37], our future research will analyze in depth the combination of these approaches. Future detailed analyses will consider both inter-individual and intra-individual dimensions, following the evolution over time of individual performances in certain types of exercises. These indicators will be correlated with different types of medical conditions as well as with the specific stages of the recovery process in order to tailor the most suitable procedure for every patient’s category. Our future research will focus on the analysis of the subjective instruments’ results, observing the effect of the experiment on the patient’s motivation, the reduction in anxiety, and the increase in self-efficacy, as well as possible correlations of these aspects based on various subgroups of patients. We plan to repeat the same testing protocol on a larger and more demographically diverse group of people in order to be able to generalize and extend the obtained results. Furthermore, we intend to extend the system to include exercises for the lower limb and therefore make it suitable for a larger set of conditions, and subsequently start a long-term testing procedure that can help us observe the real progress of patients’ lost or affected functions.

In conclusion, our integrative exploratory approach aligns with the current trends in telemedicine using the newest technological support and increasing access to medical procedures and continuous feedback from medical staff for any patient despite physical or geographical barriers together with the guarantee of home comfort. Furthermore, our complex and innovative research and clinical study ensured the inclusion of both classical and modern rehabilitation procedures, while alternating targeted physiotherapy games and psychotherapy techniques adapted to virtual reality.