## 3 Results
### Study Characteristics
#### 3.2.4 Rehabilitative Approaches  
Figure 2 summarizes our findings on the methods that are used to enhance trunk control and functions in people with neurological conditions. Delving into the different studies, it is worth mentioning that all RCTs compare different types of training. Specifically, 17 studies compared conventional training with trunk control training, core stability training, or task-specific training, which is a therapy technique focused on improving functionalities through repeated activity practice. There is agreement within these studies that training specifically targeting trunk control, core stability, and throughout task-specific training is more beneficial than conventional training alone. [PERSON] et al. (2019) compared the effectiveness of conventional balance training alone and when combined with either core stability training or task-oriented training. These findings indicated that incorporating core stability training or task-oriented training alongside conventional balance training in MS seemed beneficial, with a slight preference for the inclusion of task-oriented training, which appeared to be a more favorable approach for enhancing standing balance. Differently, four studies compared a control group that did not perform any training with an experimental group that underwent either multidisciplinary training ([PERSON] et al., 2019), balance training ([PERSON] et al., 2019), trunk resistance training ([PERSON] et al., 2019), or task-specific unsupported training ([PERSON] et al., 2019). The other RCTs compared different training programs to determine whether one was superior to the other(s). Another study ([PERSON] et al., 2019) highlighted that pelvic proprioceptive neuromuscular facilitation (PNF), in addition to task-oriented training, is more effective at improving both standing balance and gait than task-oriented training alone in stroke patients. PNF has positive effects as it improves the functions of muscles and tendons by stimulating the proprioceptive sense, which enhances muscle strength, flexibility, and balance ([PERSON] et al., 2019). In addition, PNF has positive effects when applied to the neck ([PERSON] et al., 2019; [PERSON] et al., 2019), as resistance during neck exercises also affects body trunk muscles ([PERSON] et al., 2019). Alternative rehabilitative approaches include dynamic neuromuscular stabilization (DNS) exercises, which aim to optimize motor function based on developmental kinesiology principles that focus on the maintenance of joints and segments in a central position while coordinating muscle timing along with respiratory training. In this framework, studies [37; 42] compared DNS exercises with core stability training and neurodevelopmental training. Their findings demonstrated significant improvements in trunk muscle control in the DNS group. Similarly, studies [51; 58; 77; 79; 95] showed that the addition of inspiratory muscle training or Lluzijue training (which also includes respiratory training) to conventional training or trunk training leads to greater improvements in trunk control. Furthermore, other relaxation techniques, such as Pilates and Ai Chi, have shown beneficial effects when combined with conventional training [36; 87; 97; 108]. Other rehabilitative approaches used in the studies included in this review for both stroke and SCI subjects include adapted sports. Sitting Tai Chi seemed beneficial as it had positive effects on standing and sitting balance in stroke [38] and SCI subjects [85; 101], while sitting curling training improved trunk control in SCI subjects [103]. In contrast, the addition of sitting boxing to conventional training in stroke subjects led to greater improvements in balance and gait than conventional training alone [68]. Most of the studies selected for this review used tools such as new technologies and/or the typical instruments used in the clinical setting, such as fit balls, unstable platforms with spring resistances, therapeutic stairs, deformable surfaces, and postural mirrors.