# Exergaming-Based Rehabilitation for Lateral Trunk Flexion in Parkinson's Disease: A Pilot Study
## 4 Discussion
  
* \(p<0.05\); Wilcoxon non-parametric test at the fist evaluation (T1) and at the end of each treatment (T2); Kruskal–Wallis test (non-parametric ANOVA) for the variance among 1 functions with respect to traditional treatments is not only due to a greater motivation in exercise performance, but also due to receiving real-time feedback like visual or auditory cues that facilitates motor learning [45]. As regards the neurophysiological outcomes, improvements were found in the PPT of all areas taken into consideration and in the maximal radial displacement of the erect spinae. This study demonstrated, for the first time, statistically significant increases in PPT across L3, T6, and C3 vertebrae bilaterally after an exergaming rehabilitation protocol in patients with PD and LTF. A possible explanation of this result may be related to the exercise-induced desensitization effect, both peripherally (by suppression of pain signals) and centrally (by pain modulation) [47]. Notably, exergaming can be considered as a dual task training system, combining active exercise and cognitive training in an interactive virtual game environment [43; 48]. This association seems to be more effective in terms of neuroplasticity than active exercise or cognitive training alone [47; 49]. Indeed, it may induce an up-regulation of cortical connectivity associated with cognitive tasks (divided attention, inhibition of response, sustained attention) [48], and it could normalize GABA-glutamate neurotransmission [47], which in turn is related to pain modulation [50; 51]. Moreover, exergaming could lead to functional changes in brain areas, such as the anterior insula, anterior and posterior cingulate cortex, and basal ganglia, which are involved in pain modulation [30; 31; 52]. A second neurophysiological outcome of this study was the tensiomyography (TMG), which was used to assess the mechanical properties of the muscles, allowing us to detect changes and asymmetries [37; 38; 39; 40]. No previous study used TMG to evaluate the effect of treatments in PD, nor in LTF. The results of our study revealed a statistically significant improvement in the maximal radial displacement (Dm) of the ipsilateral erect spinae after an exergaming rehabilitation protocol. The Dm parameters of TMG represent the muscles' spatial transverse deformation; thus, a reduced Dm is related to an increased muscle stiffness. In our study, before the exergaming treatment, the LTF group showed a statistically significant reduction in Dm in the ipsilateral erect spinae compared to the HC group, but it was normalized at the end of treatments. In fact, no differences were found between the LTF and HC groups at t2 in the side of the lateral trunk deviation, which can be associated with a clinical improvement of both the lateral and the anterior/posterior inclination of the trunk. Taken together, these findings suggest that exergaming operates through both peripheral and central mechanisms: peripherally, it seems to lead to a trunk postural correction through a decrease in muscle stiffness in the ipsilateral erect spinae, whilst centrally, it seems to enhance pain modulation through dual-task training, leading to an upregulation of the cortical connectivity associated to cognitive tasks. From a psychological perspective, exergaming also appears to enhance motivation and adherence to therapy. Prior research has shown that in patients with neurodegenerative disorders, gamified rehabilitation strategies increase engagement, provide positive feedback, and help distract from the discomfort of treatment, leading to better health outcomes [53]. As regards the limitations of the present work, first, the small sample size may have not allowed us to highlight differences in tensiomyography before and after the exergaming rehabilitation protocol, nor between the LFT and HC groups. However, our study was a pilot study which aimed to investigate the feasibility of a rehabilitation protocol with exergaming in a population with PD and LTF.