Virtual Reality (VR) for Standing Balance

Discussion

A meta-analysis by Abou et al. (2020), including six studies and 108 patients with SCI, found that after completion of VR therapy, standing balance significantly improved compared with baseline. The analysis of the BBS scale showed a statistically significant within-group difference (MD=4.22; 95% CI 1.78-6.66; p<.01) and the analysis of the activities-specific balance confidence (ABC) scale showed a statistically significant within-group difference (MD=8.53; 95% CI 2.52- 14.53; p<.01) (Abou et al. 2020). Other systematic reviews have also shown promising effects in standing balance in people with SCI (Alashram et al. 2020; de Araújo et al. 2020; De Miguel-Rubio et al. 2020); however, there is a strong need for further well-designed RCTs investigating the effect of VR therapy on different mobility outcomes among persons with SCI and providing information about VR long-term effects in order to develop robust guidelines (Abou et al. 2020; Yeo et al. 2019).

There are two studies which assessed the effects of performing a VR training program on participants with acute SCI. The prospective control trial of Sengupta et al. (2020) assessed the inclusion of VR training focused on static and dynamic balance in patients with acute (less than 6 months since injury) paraplegia (n=11) and tetraplegia (n=21), and with motor complete (n=18) or motor incomplete (n=22) SCI. After 3 weeks, with five sessions per week, of routine conventional therapy and VR training sessions (in sitting or standing depending on each participant’s functional ability), participants did not show any significant differences with respect to the control group (only physical therapy sessions) for standing balance (BBS and balance section of POMA-B) (Sengupta et al. 2020). Conversely, the pre-post study of Shin et al. (2021) assessed if 30 min of BWSTT plus one hour of conventional physiotherapy, five times per week, had effects on standing balance in 13 patients with acute tetraplegia (n=11) or paraplegia (n=2) (mean time since injury 48 [19-139] days). BWSTT was performed with the Morning Walk®, which is an end-effector type robot and the first gait training robot using a saddle for weight support, and with visual feedback through a VR screen, so participants could have the experience of walking through a park or forest according to the gait speed (Shin et al. 2021). After 4 weeks of intervention, standing balance (BBS), gait speed (10MWT), gait endurance (6MWT), muscle strength (LEMS) and walking ability (WISCI II) showed significant improvements; and one patient with paraplegia AIS C improved to AIS D (Shin et al. 2021).

Several studies have been conducted in patients with chronic SCI who performed different training programs using VR (An & Park 2018, 2022; D’Addio et al. 2014; van Dijsseldonk et al. 2018; Villiger et al. 2013, 2015, 2017; Wall et al. 2015), or standing or BWSTT training programs coupled with different biofeedback approaches (Amatachaya et al. 2023; Cheung et al. 2019; Houston et al. 2020, 2021; Nithiatthawanon et al. 2020; Pramodhyak et al. 2016; Sayenko et al. 2010; Tamburella et al. 2013); showing overall benefits in standing balance outcome measures.

For VR, the most recent RCT was conducted by An and Park (2022), which included 40 patients with tetraplegia. Similar to a rehabilitation intervention, the VR intervention consisted of 12 sessions of performing a virtual soccer game while sitting in a wheelchair for 30 minutes three times a week (An & Park 2022). At the end of the intervention, both groups showed improvements in walking speed (10MWT) and standing balance (TUG and FTSTS), but the experimental group had significantly better results than the control group (An & Park 2022). The prospective controlled trial of D’Addio et al. (2014) included 30 participants with incomplete and chronic SCI who received a standard rehabilitation protocol for balance training. Participants in the experimental group (n=15) received, in addition, a Nintendo Wii Fit balance training, along with its balance board (D’Addio et al. 2014). After 12 weeks of training, both groups showed improvements in standing balance (BBS and posturography testing); however, the experimental group showed significantly higher scores (D’Addio et al. 2014).

For other biofeedback approaches, the cross-over RCT of Nithiatthawanon et al. (2020) included 30 participants with SCI (10 participants with tetraplegia and 20 with paraplegia) and the ability to walk independently. The aim of the study was to compare the immediate benefits of adding (or not adding) visual feedback relating to the amount of lower limb loading on the stance leg to alert the participants and the therapist of the adequate load (at least 80% of the participant’s body weight) during a single 20 min-session comprising body-weight shifting and lower limb loading during stepping and overground walking training (Nithiatthawanon et al. 2020). It was shown that the TUG test and maximal lower limb loading of the less affected leg were improved only in the experimental group; although 10MWT, FTSST and maximal lower limb loading of the most affected leg improved similarly in both groups (Nithiatthawanon et al. 2020). Based on these results, the recent RCT of Amatachaya et al. (2023) carried out the same study protocol but over four weeks (30 min/day, 5 days/week) in participants with incomplete and chronic SCI. At the end of the intervention, the mobility improvement of participants in the experimental intervention group was significantly greater than that of the participants in the control intervention group (p<0.05); however, this difference was not found at six months after the training programs (Amatachaya et al. 2023). In addition, during the six months after the training, the number of participants with falls was significantly lower in the experimental group than in the control group (Amatachaya et al. 2023). The RCT of Pramodhyak et al. (2016) included 32 participants with incomplete and chronic SCI who performed an overground walking training protocol at their fastest safe speed with or without a visuotemporal cue for five consecutive days. After the training protocol, the improvements in standing balance (TUG, FTSTS) were significantly higher in the group receiving the visuotemporal cue (Pramodhyak et al. 2016). The RCT of Cheung et al. (2019) included 16 participants with incomplete SCI who received, apart from standard physiotherapy, BWSTT three times per week during eight weeks (active group) or passive lower limb mobilization training (control group). BWSTT was performed with the Lokomat system, EMG biofeedback system was applied to the bilateral vastus lateralis, and audio feedback was generated if the muscle activation was less than 30% of maximal recruitment to encourage active participation during the stance phase of the gait cycle (Cheung et al. 2019). It should be noted that a significant time x group interaction was found only in the active group in WISCI II and mobility sub-score of SCIM-III, but not in the walking speed (Cheung et al. 2019).

Conclusions

Acute SCI (<1 year)

There is level 2 evidence (from 1 prospective control trial: Sengupta et al. 2020) that VR training added to routine conventional therapy, in comparison with only conventional therapy, does not provide better improvements in standing balance in patients with acute SCI.

There is level 4 evidence (from 1 pre-post study: Shin et al. 2021) that RAGT (with Morning Walk®) with visual feedback and conventional physiotherapy provides improvements in standing balance (BBS), gait speed (10MWT), gait endurance (6MWT), muscle strength (LEMS) and walking ability (WISCI II) in patients with acute (mean time since injury 48 days) motor incomplete SCI.

Chronic SCI (>1 year)

There is level 1 evidence (from 1 RCT: An & Park 2022) that a VR intervention, consisting of a virtual soccer game performed while sitting in a wheelchair, provides better improvements in walking speed (10MWT) and standing balance (FTSTS and TUG), than a similar rehabilitation intervention without the VR component in patients with chronic motor incomplete SCI and tetraplegia.

There is level 2 evidence (from 1 prospective controlled trial: D’Addio et al. 2014) that the addition of a Nintendo Wii Fit balance training to a standard rehabilitation protocol for balance training for 12 weeks provides significantly higher improvements in standing balance (BBS and posturography) in participants with chronic and incomplete SCI.

There is level 1 evidence (from 2 cross-over RCTs: Amatachaya et al. 2023; Nithiatthawanon et al. 2020) that adding visual feedback relating to the amount of lower limb loading during body-weight shifting, stepping, and overground walking training provides improvements on the TUG test, FTSTS, and number of fallers in participants with chronic SCI.

There is level 1 evidence (from 1 RCT: Cheung et al. 2019) that BWSTT (performed with the Lokomat system and an EMG biofeedback system to encourage active participation during the stance phase of the gait cycle) during 8 weeks provides a significant time x group interaction in WISCI II and mobility sub-score of SCIM-III (but not in walking speed), in comparison with a passive lower limb mobilization training in participants with incomplete SCI.

There is level 2 evidence (from 1 RCT: Pramodhyak et al. 2016) that an overground walking training protocol for five consecutive days at the fastest safe speed with a visuotemporal cue provides significantly higher improvements in standing balance (TUG, FTSTS) than the same protocol without the cue in people with chronic and incomplete SCI.

There is level 4 evidence (from several pre-post studies) that different VR training protocols provide significant improvements in standing balance in people with chronic and incomplete SCI.