## 4 Discussion  
In this study, a physical therapy program including visuomotor training provided significantly faster improvement of lower limb function after orthopedic surgery than conventional rehabilitation. Moreover, VTG compared to CG achieved greater improvement in LEFS score and in almost all outcome measures, including pain NRS, by the term of 4 weeks of treatment. These results are in line with those obtained in different cases, such as on neurological subjects and athletes [20; 23; 24; 29]. After musculoskeletal disorder, a key limitation of rehabilitation is the inability to facilitate the acquisition of injury-resistant motor patterns that persist beyond the clinic [30]. This limitation likely contributes to high rates of secondary injury and long-term pathologic sequelae, such as asymmetric joint loading and pain. The incorporation of motor learning principles may facilitate the acquisition of lasting, injury-resistant movement patterns that can facilitate neuroplasticity [31]. Specifically, the use of an external focus of attention and implicit learning may serve an adjunctive role [32]. Human motion is based on the refined interplay between the intention of moving and continuous monitoring from sensory information that adjusts such motor action [33]. Multi-joint movements, like locomotion, require the activation of the nervous and musculoskeletal systems to a large extent. The spinal interneuronal networks, termed central pattern generators, respond to signals in proprioceptive and skin afferents, modifying the locomotor pattern in cooperation with descending signals from the brainstem structures and the cerebral cortex. Information processing between the basal ganglia, cerebellum, and brainstem may enable automatic regulation of muscle tone and rhythmic limb movements in the absence of conscious awareness [34]. When a locomoting subject experiences a musculoskeletal disorder in the lower limbs, they somewhat alter this sensory-motor processing and develop individual compensation strategies to avoid pain during walking [35]. In particular, in the case of subjects undergoing joint replacement for osteoarthritis, these strategies are expressed in gait patterns characterized by clearly evasive movements, which are so highly automated that they still endure post-surgery [36]. Possible consequences include side asymmetries in gait parameters as shown by our population at baseline. The asymmetry index significantly decreased in both groups across the study; however, the VTG showed a greater reduction than CG at T1. The fact that a musculoskeletal injury in an anatomic district may affect joint movement at other levels due to a disruption of the afferent stimuli processing, especially for patients with the more severe disorders [18], suggests that training of global movement control is essential for rehabilitating these patients. A conventional approach may be insufficient to break up existing automatisms and initiate new movement patterns in the brief term. Furthermore, immobilization and inactivity after injury and/or surgery may also lead to cognitive dysfunctions [37], and the motor cortex undergoes a reorganization that is correlated with the duration of immobilization and is independent of age [38]. Hence, the importance of a timely approach that counteracts the slowdown of sensory-motor processes induced by immobilization. A combined sensory-motor training modality is mainly used in neurological rehabilitation, where it is reportedly more effective than conventional motor-oriented approaches [39], or in athletes [40; 41]. In orthopedic rehabilitation, there is poor evidence of sensory-motor training [36; 42; 43] and even less for visuomotor training, so this is one of the first studies investigating the efficacy of this approach in subjects with musculoskeletal disorders, whereby VTG recipients experienced a greater reduction in pain than compared with CG, with a NRS score more than halved by 4 weeks as it decreased from 6.8 \(\pm\) 1.4 to 3.1 \(\pm\) 1.