Spinal cord injury is defined as any damage to any part of the spine due to trauma, tumor or infection. It can be traumatic in nature when the injury results from physical trauma (car accidents, work accidents, sports injuries) or non-traumatic in nature when it is caused by an underlying pathology such as an infection, tumors of any nature, musculoskeletal diseases [1]. Spinal cord injuries can be complete or incomplete. Incomplete lesions indicate the retention of functions that are still active. Complete lesions are characterized by a total functional deficit of a motor and sensory nature [2]. Depending on the level of the injury, there are different types of paralysis that can be grouped as follows: tetraplegia (upper limbs, torso, lower limbs and pelvic organs are affected) and paraplegia (torso, lower limbs and pelvic organs are affected). In conclusion, a crucial factor in determining the severity of spinal cord injury is the determination of the spinal cord segments affected by the injury, so the rehabilitation plan can be adapted to the needs of the patient [3].

Between 10 and 83 million people suffer from spinal cord injury every year, globally [4]. Statistics show that in Spain, annually, about 1000 cases of spinal cord injury occur due to injuries, half of which are due to traffic accidents, and the other half are due to sports accidents, falls and blows [5].

According to Kraus J.F.’s study, the incidence of spinal cord injury was much higher in males than in females (80.1 in males compared to 27.5 in females per million population, p 0.001) [6]. In addition to a detailed incidence of spinal cord injury per year, the study by Kraus J.F. It also showed the annual average of deaths caused by spinal cord injury among males and females as well as race [6]. In addition to a detailed incidence of spinal cord injury per year, the study by Kraus J.F. It also showed the annual average of deaths caused by spinal cord injury among males and females as well as race [6] (Fig. 1).

Kraus J.F. identified that the most significant percentage of spinal cord injuries was due to external causes (p 0.0001), and the fatality rate was significant in favor of external factors (p 0.0001). The study included motor accidents, falls, firearms, recreation, etc. things that males do predominantly compared to females [6] (Table 1).

Another study by Fitzharris M. shows that in 2007 the incidence of traumatic spinal cord injury cases was 179,312, with a 95% confidence index (CIs). Fitzharris also states that the incidence of traumatic spinal cord injury can vary between 132967 and 225658 cases, with an overall rate of 27.5 cases per million people (out of a population of 131 countries: 6.250 billion) [7]. According to Furlan J.C. in 2013, the incidence rate of spinal cord injury in America ranged from 20.7 to 83 people per million inhabitants according to Table 2 [8]. This is in line with the values offered by Kraus J.F. in 1975, but suggests a decrease in incidence compared to Kraus’ time.

Furlan J.C. also shows in the study Global Incidence and Prevalence of Traumatic Spinal Cord Injury that the incidence rate of spinal cord injuries in Europe is lower ranging from 8.0 people in Spain to 130.6 people per million population in Bulgaria (Table 3) [8]. The incident was filed by Furlan J.C. in 2013 for Bucharest/Romania (period 1992–1993, hospitalized patients Dr. G. Marinescu Hospital) was 28.5/million inhabitants [8]. If we take into account the figures mentioned by Kraus J.F. (80.1 in males compared to 27.5 in females per million population, p 0.001), means by the rule of three simple ones, the affectation of the male sex in a million population is (0.00801%), compared to the affectation of the female sex which is located at (0.00275%) [6].

Most patients suffer irreversible damage, in (96.9%) of cases they have difficulties and limitations in mobility, (81.1%) of cases have difficulties in self-care activities and (84.3%) have difficulties in performing domestic tasks. Another important aspect in the rehabilitation of patients with spinal cord injuries is the economic one, the associated costs being the higher the degree of damage to the patient. Also, the degree of disability with which the patient remains for a long time is a key aspect in the share of costs for rehabilitation [9]. Specialists suggest the implementation of technologies that involve low costs in order to improve the quality of life of patients with spinal cord injury.

The concept of virtual reality derives from the terms reality and virtual and can be translated as an imaginative reality, generated by the computer. In conclusion, virtual reality is able to generate a wide range of exciting user experiences. Virtual reality devices were used for the first time in the military industry, the latter using different sensory-motor stimulation devices in training but also different remote control procedures [10]. Adaptability is the main reason why virtual reality has attracted the attention of health experts. Virtual reality offers numerous clinical applications, independent of the user’s location and health, provides a stimulating and interactive environment, partially comparable to real-life experiences [11, 12, 13, 14]. Currently, different types of protocols are used to induce and facilitate neural regeneration processes [15]. Being a technology based on interaction, it increases the motivation and the degree of user involvement, which visibly improves the adherence to the treatment, especially in the case of recovery protocols that involve repetitive movements [16, 17, 18, 19, 20].

Studies have reported that virtual reality has promising effects in the clinical rehabilitation of many neurological disorders but also in improving physical and cognitive function caused by injuries caused by brain trauma [21, 22]. It has been shown that virtual reality can improve balance and gait recovery after stroke, spinal cord injury and cerebral palsy [23, 24, 25, 26, 27, 28, 29]. Virtual reality has become a fairly attractive strategy for patients with spinal cord injury allowing patients to experience a high degree of body awareness, providing multisensory feedback [26]. Experimental studies emphasize the importance of combining multisensory stimulation for patients with spinal cord injury in both the acute and chronic stages of the disease [27]. Often, after spinal cord injury, patients become disconnected from the sensory information of congruent feedback and the treatment should reconnect them to this type of feedback. This multisensory feedback can induce changes in the sensory-motor network [19].

International virtual libraries such as ISI-Thomson Web of Science, Scopus and the (National Center for Biotechnology Information (NCBI) have been accessed in this article. In all of the international virtual libraries the search criteria selected were “title”, “abstract” and “keywords”. For all the virtual libraries the search engine was “Spinal Cord virtual reality” were we found:

• Scopus virtual library, a number of 327 articles from 1996–2021 were identified;

• ISI Thomson Web of Science virtual library a number of 77 articles from 2017–2021 were identified;

• NCBI (Pub MedCentral) a number of 994 articles from 2000–2022 were identified (Fig. 2).

In order to reproduce a quality review, we wanted to use only the most prestigious virtual libraries, where the selection criteria, the quality of the reviewers, the quality of the information, etc. are higher than in other virtual libraries.

In order to create the review, were selected just articles had as research direction the re-education of the spinal cord injuries using virtual reality tools, so that from all the articles identified in the 3 international databases, only those articles were selected that met the following criteria:

• to be in the medical field;

• to be in the field of medical recovery/rehabilitation;

• to be treated for spinal cord injury.

As we will see in the results, some years have not been beneficial for the re-education of spinal cord injuries using virtual reality tools, as there are no articles addressing spinal cord rehabilitation through virtual reality.

In 2000, Riva spoke about the flexibility of computer-generated programs through 3-D navigation, noting that this method offers therapists a variety of possibilities. In addition, he mentions that virtual reality offers a great ability to increase interaction with the environment in a controlled manner, but also with increased quality [30]. Schmidt presented in 2002 the benefits of using the conventional method of using the treadmill and the need for the therapist’s effort in assisting the patient, comparable to a robotic device that allows the therapist to attach the device legs and sensors, to enter the necessary data in computer and to assist the patient only through coordination, guidance, motivation [31]. In 2003, in the Journal of Robotics, a study was published that conducted a comparative study on mice in which a physical treadmill was used with a virtual one generated by robots. The results were more impactful on the physical treadmill than on that generated by the robots [32].

A question raised in 2004 by Kushner, was on nervous influences, namely, whether this virtual reality technology influences our nervous system or whether movement in a virtual environment motivates the patient to perform [33]. In 2006, there were still discussions about innovative technologies that induce and perform passive movement to stimulate the motor efficiency of the spine, but also about technologies that stimulate voluntary patient movements, concluding that stronger evidence is needed to demonstrate the applicability of these technologies in rehabilitation [34].

Wellner wrote in 2007 that robots intended for rehabilitation during that period consisted of moving the lower limbs of patients on a predefined trajectory, not stimulating them enough because the device moves the lower limbs in the absence of patient effort, unable to observe their course. The attachment of an accrual, ventilator and audio system allows the patient to complete a route, thus increasing the recovery quality of the devices from that period [35].

A comparative study on the psychological effects offered by virtual reality vs. without virtual reality in cases of spinal cord heart injury was conducted in 2009 by Chen, where out of thirty patients, he formed two groups, a group where he used virtual reality and in a control group where he did not use virtual reality, he concluded that virtual reality helped to relax patients and induce a state of calm in them [24].

A review conducted in 2009 and presents the broad spectrum of virtual reality use in the rehabilitation of stroke, traumatic brain injuries, spinal cord injuries, intellectual disabilities and cerebral palsy and intellectual disabilities, but at the same time it highlights the beneficial effects that virtual reality has in such cases as: improves motor aspects, improves cognitive impairment and motivation [36].

Also, another review in 2010 found that most virtual reality articles contained a small number of patients and were intended to test and validate their own devices, rather than to demonstrate clinical efficacy in rehabilitation, concluding that virtual reality is a promising method for the future of neural rehabilitation, only studies should focus on demonstrating its effectiveness compared to traditional techniques [37].

De Mauro mentions in his study in 2011, about the benefits of using virtual reality in rehabilitating patients with spinal cord injuries, mentioning that it is a suitable technology due to its ability to stimulate real life, excludes monotony and at the same time motivating the patient [38].

Villiger points out in 2011 that intense sessions using virtual reality, can make possible the restoration of cortical networks, thus leading to a reduction of neuropathic pain and automatically improving motor function, applying a virtual water rehabilitation protocol to six patients, concluding that the protocol used can bring benefits in both reducing neuropathic pain and automatically improving motor function [39].

The year 2012 offered us an article that tried to rehabilitate through virtual reality the patients with spinal cord injury restoring their driving skills. Before 2012, no quality of life studies have been identified using virtual rehabilitation in regaining driving skills. The study was performed on a group of twelve patients with spinal cord injury and showed impressive results on regaining the driving skills of these patients [40]. Mazzone mentions that almost (70%) of spinal injury patients will develop shoulder pain at some point. He did a study on five patients with shoulder pain, a study in which patients performed shoulder exercises with and without virtual reality, not identifying major differences between the kinematics of the two, but muscle activation was similar or higher on exercises where reality was used virtual [41].

In 2013, Dimbwadyo argued that virtual reality is a system that induces motor activity and increased motor control, while promoting better cortical reorganization through mirror neurons system activation. To demonstrate this, he conducted a study of twelve patients trying to demonstrate the effectiveness of virtual reality through a system called Toyra®. The end of the study showed that patients who used the Toyra® system had improvements in parameters such as dexterity, coordination, grip, but also observed kinematic parameters [42, 43]. Another virtual reality study called Toyra® on parameters such as range of motion, accuracy, repeatability and agility, showed that it can be used as an effective method in the motor assessment of the upper limb of patients with spinal cord injury [44]. In 2013 there is another study aimed at increasing the quality of life of patients, by using virtual reality to increase the performance of wheelchairs. The study was conducted on a group of ten people, regular users of wheelchairs. The results showed that the virtual driving simulator is a promising virtual reality tool to evaluate and increase the performance of wheelchair use [45].

In the same year there is a study that addresses virtual reality in terms of increasing quality of life, but also the reintegration of people in recreational and sports activities. The study used virtual reality in sailing simulators over a twelve-weeks period as a pilot treatment for the recovery of sailing enthusiasts. At the end of the twelve weeks all subjects demonstrated simple navigator skills, the ability to sail independently at moderate currents as well as speed as well as improved psychological health [46]. Villiger and colleagues demonstrated in 2013 that Augmented Virtual Reality has improved gait, balance, and strength in patients with spinal cord injury in lower limb cases, but in addition to that, the intensity and pain of neuropathy has decreased. A comparative study was conducted in 2014 on nine patients with spinal cord injury. One group used virtual reality using CyberTouch™ gloves, and the other group performed traditional rehabilitation, thirty minutes a day, twice a week, for two weeks [20]. The results obtained were not statistically significant, but the group where apparent virtual reality was used obtained better results in muscle balance, as well as in functional parameters such as dexterity, coordination and finite grips [47]. Mao Y. only praises the virtual reality used in rehabilitation, saying that when patients use virtual reality in prefrontal treatment sessions, parietal cortical areas and other motor cortical networks are activated, and this activation leads to the reconstruction of neurons in the cerebral cortex [48].

Another conclusion of Mao, emphasizes that virtual reality visibly improves neurological function in patients with spinal cord injury, cerebral palsy and other neurological disorders, this being possible by activating the cerebral cortex and improving the temporal-spatial orientation of patients, thus facilitating the control of the level balance and improving motor function [20]. A comparative study was conducted in 2015 between Lokomat (virtual reality) and passive pedaling; concluding that patients who benefited from Lokomat sessions had improvements in metabolic markers and those who benefited from passive pedaling sessions did not [49].

In 2016, nine patients participated in a spinal cord injury rehabilitation study using virtual reality combined with CyberTouch. The patients formed two groups where virtual reality was used with CyberTouch™ and the other group performed only the traditional rehabilitation, for a period of two weeks. The results did not show statistically significant changes, but the group that used virtual reality obtained changes in muscle balance, dexterity, coordination and finite grip [27]. Khurana conducted a comparative study on a group of thirty patients (twenty-eight men’s and two woman’s) with traumatic spinal cord injury. In order to conduct the study, patients were divided into two groups: group A benefited from balance training based on virtual reality play, and group B performed specific exercises for balance. The program lasted for four weeks, with five sessions lasting forty-five minutes each week. The results showed that group A, which performed balance training based on virtual reality play, performed better than group B. Another study compared the effectiveness of virtual reality using the Nintendo Wii system and conventional occupational therapy in improving upper limb function in patients with spinal cord injury [50]. The study involved twenty-two patients with spinal cord injury spinal cord injury, who were randomly assigned to two groups, group one received thirty minutes of virtual reality therapy and conventional occupational therapy for thirty minutes, at the same time the second group, for thirty minutes was subjected only to therapy conventional occupational. Both groups worked three times a week for six weeks and were evaluated at baseline and then at two weeks, four weeks, and six weeks from the start of therapy.

Evaluations performed after four weeks and after six weeks of treatment did not highlight significant differences between the two groups, in conclusion virtual reality has not been shown to be effective in improving upper limb function [51]. A study of a 60-year-old patient with spinal cord injury, incompletely affected cervix, wanted to assess cognitive and motor outcomes after a combined rehabilitation program, using the standard cognitive approach combined with virtual reality. The patient had a moderate tetra paresis that mainly affected the left side. It was first subjected to the standard treatment protocol and then to a combined therapeutic approach, traditional physiotherapy combined with virtual reality. The combined therapeutic approach has shown significant improvements in cognitive function, a significant reduction in symptoms of anxiety and depression but also improvements in motor performance and balance [52]. A pilot study was conducted to investigate the effects of rehabilitation therapy using a new device, iCycle. We analyzed eleven patients with incomplete spinal cord injury in different evolutionary stages, which underwent twelve trainings with iCycle. The functions were evaluated before the start of the trainings using the international standards described in the specialized literature. Improvements in the neurological classification for spinal cord injury motor score showed only two of the six patients with chronic injuries and four of the five patients with acute injuries. Five out of eleven participants showed moderate improvements in voluntary cycling Power output which did not correlate with changes in international standards for neurological classification for spinal cord injury motor score. At the end of the study, it was concluded that iCycle was not suitable for participants who were too weak to generate a detectable voluntary couple or whose effort led to a negative couple. Improved neurological classification for spinal cord injury motor score were associated with iCycle training in chronic participants. In sub-acute patients, changes due to iCycle training could not be distinguished [53].

In 2019, Chi [54] conducted a systematic review of spinal cord injury associated with neuropathic pain, concluding that the virtual reality applied in spinal cord injury -Associated neuropathic pain may reduce its effects, but the results on the analgesic effect are still unclear.

Porter et al. [55] presents in a study the use of a robot with a virtual reality platform in the rehabilitation of the upper limbs of patients with spinal cord injury spinal cord injury. The virtual reality platform consists of three different games, which offer the patient the opportunity to interact with the virtual scene using the upper limbs. During the therapy data are collected regarding the motor qualities, the system can be adapted according to the patient’s needs. The efficiency of the system is proven by the collected data, which proves to be effective in the therapy of patients with spinal cord injury [55]. A study was conducted to analyze the results obtained in the case of conventional therapy combined with virtual reality and simple conventional therapy. The study included patients with spinal cord injury with upper limb involvement, the control group received sixty minutes of conventional therapy per day, four days per week for four weeks, the experimental group received thirty minutes of virtual reality and thirty minutes conventional therapy four days a week for four weeks. The measurements were performed using the specific tests described in the literature, these being performed at the beginning of the study and at the end of it. Clamping power and K-SCIM score improved significantly in the experimental group after intervention. When comparing the differences between the groups, elbow extensor, wrist extensor, ASIA-UEMS, clamping power, lateral clamping power and palmar clamping power were significantly improved [56].

In 2020, Sengupta et al. [57], conducted a study through which he wanted to evaluate the effects of a game-based virtual reality training program for torso balance and postural control in patients with spinal cord injury. Patients were divided into two groups, a control group and an experimental group, the groups being subjected to the conventional rehabilitation program. Five days a week for three weeks the experimental group underwent additional training with virtual reality therapy. The tests performed initially but also at the end of the treatment consisted of standard tests described by the specialized literature. The analysis of the tests performed did not show significant differences between the two groups, in terms of trunk mobility and patient posture. Also, no significant difference was observed in the analysis between groups depending on the severity of spinal cord injury spinal cord injury [57]. Another study investigated the effect of interaction with simulated virtual reality environments provided on the patient’s mood and the effect of a higher number of virtual reality sessions over a period of one week on the depressive symptoms of people with spinal cord injury. During the week of therapy, the patients underwent three virtual reality sessions of twenty minutes each, three consecutive days. The state of control involved a regular practice of rehabilitation for a week. The evaluation was performed based on a standardized questionnaire at the beginning of therapy, after the first week, after the second week, respectively after the third week of treatment. Levels of happiness, relaxation and feeling of well-being were significantly higher after interacting with each virtual reality session. It was concluded that the interaction with simulated natural environments, provided by virtual reality can favorably influence the psycho-emotional health of people with spinal cord injury [58].

In 2020, Abou demonstrated the effectiveness of virtual therapy in rehabilitating sitting and orthostatic balance, as well as improving gait in patients with spinal cord injury [59]. Since 2020, Amaranta wrote in article: “Effectiveness of Virtual Reality on Functional Performance after Spinal Cord Injury: A Systematic Review and Meta-Analysis of Randomized Controlled Trials” that virtual reality is not as effective as conventional therapy in improving physical performance in cases of patients with spinal cord injury [60].

In 2021, Putrino conducted a study the purpose of this study was to investigate the effect of two different virtual reality protocols on pain intensity in people with spinal cord injury. Participants were recruited from the Burke Institute for Medical Research’s spinal cord injury database from 2015 to 2016. Virtual reality was used as a pain management tool among people with acute, chronic, neuropathic pain and phantom limb pain. Virtual reality therapy also appears as a promising alternative treatment for people with spinal cord injury. The results indicated a mean decrease in pain after virtual reality intervention. The results obtained in the study were comparable with the results already existing in the literature, which once again confirms the effects of virtual reality therapy in pain therapy in patients with spinal cord injury [61].

Leemhuis et al. [62], describe the potential benefits of using virtual reality in patients with spinal cord injury to re-educate sensory-motor feedback. It was found that placing patients in a virtual environment enriches sensory perceptions and implicitly motor ones, through the processes of neuronal regeneration and plasticity [62]. The results showed that when virtual reality therapy is used concomitantly with conventional therapy the treatment results are visibly improved. In conclusion, virtual reality therapy combined with standard rehabilitation therapy could be an ideal rehabilitation tool for improving lower extremity function in patients with spinal cord injury. The study entitled Effectiveness of virtual reality-based exercise therapy in rehabilitation: A scoping review, tried to show the effectiveness of virtual reality in therapeutic physical exercises, thus fueling future research in this directive. Based on the information obtained, the authors concluded that virtual reality based on therapeutic physical exercises have a great potential in rehabilitation, but studies in this direction are still needed [63].

A study conducted in 2021 by Orsatti wanted to demonstrate the effectiveness of virtual reality intervention in the neuronal rehabilitation of patients with spinal cord injuries. This review was conducted over a period of ten years, from 2010–2020, which concluded with the conclusion that virtual reality is an effective therapy, but it is an effective complementary therapy, which tells us that it must come to the aid of conventional physical therapy [64]. Rutkowski also did a systematic review of virtual reality in upper limb, lower limb, gait and balance rehabilitation, but in the end concluded that virtual reality along with virtual games can bring considerable advantage in upper limb rehabilitation, but not for hand and walk. Virtual reality can also improve balance in cases of patients with neurological problems [65].

The same thing was identified by Lee in 2021 that the use of virtual reality can be a real tool in balance rehabilitation programs for patients with spinal cord injury. Min-Jae Lee conducted a study on twenty subjects with spinal cord injury, who were divided into two groups, a control group and an experimental group. Patients underwent a recovery program that included virtual reality, designed to improve balance. Each session lasts thirty minutes twice a week for eight weeks. Equilibrium functions were measured according to the protocols described in the literature [66].

Between ten and 83 million people suffer from spinal cord injury every year, globally. According to the results presented in our review we can conclude that the current evidence of virtual reality interventions to improve functional performance after spinal cord injury is limited. The articles analyzed in the review highlighted that virtual reality cannot be more effective than conventional therapy in improving functional performance in patients with spinal cord injury. In addition to the high costs of purchasing a virtual reality device, the purchase of software packages or various interactions depending on the specific needs of patients (age/sex/profession/hobby, etc.) should also be considered.

Although the real mechanisms underlying the therapeutic effects of virtual reality remain unclear, therapy is being approached to prove the effectiveness of a developed product and not to emphasize the mechanism of action on the condition and the patient. The evidence reported so far suggests that virtual reality procedures should be used in conjunction with standard/conventional rehabilitation so that the patient can benefit from both modern and conventional treatment, thus enhancing the quality of treatment provided. Recent evidence from the literature has shown that virtual reality may be useful as a therapeutic tool in patients with spinal cord injury to improve motor function or motor skills, to reduce pain perception and improve psychological/motivational outcomes by improving feedback physiologicaly.

As most articles have shown, the usefulness of virtual reality in people with spinal cord injury can be considered both in the acute phase and in the chronic phase of spinal cord injury treatment, which gives us a wide range of work with this tool. As specified above, most authors have attempted to demonstrate the efficacy of the product without regard to the clear mechanism of action and the medium- and long-term impact on patients’ health/quality of life. Within a limited number of found authors, they tried to work on the patient’s quality of life using virtual reality in the rehabilitation of daily activities, such as the reintegration of patients in recreational activities. These articles focused primarily on issues such as improving the patient’s quality of life, promoting the activity prior to practicing a preferred trade/hobby, thus demonstrating their effectiveness in directions where conventional rehabilitation cannot be applied.

The introduction was identified and edited by MI, the access to databases together with the design of the working methodology was performed by MT, the search in the virtual libraries and the browsing of all articles (relevant and irrelevant) was performed by to CI and IC. The entire review was supervised and guided by MR. All authors contributed to editorial changes in the manuscript. All authors read and approved the final manuscript.

The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of Department of Medical Biosciences, ‘Gr.T.Popa’ University of Medicine and Pharmacy, Iasi, Romania.

Not applicable.

This research received no external funding.

The authors declare no conflict of interest.