## 4 Discussion  
This study proposes a potential VR game solution for musculoskeletal injury rehabilitation in elite or amateur soccer players. Based on the physical fitness components that must be trained in the return to the training recovery phase, five virtual games were built with high perceived usability scores, experience, execution/quality of the exercise performed, and the final punctuation achieved in each game. Second, RPE and HR monitoring were used to test a complete rehabilitation session using five virtual games regarding intensity requested throughout the three training session phases (warm-up, conditioning, cool-down). The RPE tracking throughout the session showed better results than HR regarding the intensity expected in each training session phase. Nonetheless, both indicators showed an increase in the first phase of the training session and a decrease in the last stage, which agrees with the recommendations for prescribing a training session. First, one of the most important issues when a VR game solution for musculoskeletal injury rehabilitation is developed is for it to have acceptance, be usable, support future adoption, and provide interest/enjoyment to the end users [28; 29]. In our study, a high perception of usability and experience was found, and the estimated time of the experience was lower than the actual time spent, representing a high immersion with the system. A recent review shows that the number of studies describing the acceptability and usability of VR in neuromotor rehabilitation is growing in interest [30]. However, studies conducted on professional sports athletes are scarce. With the same purpose as our study but using a different sample, [PERSON] et al. [27]) conducted an exploratory study to examine the acceptance, future adoption, interest/enjoyment, and usability of an immersive virtual reality system for exercise training [31]. The results were closer to ours, showing that participants noted a significant preference, acceptance, interest/enjoyment, and usability  
Figure 2: Variation in games’ heart rate across a complete rehabilitation session to recover from musculoskeletal injury. of an immersive virtual reality system. However, contrary to [PERSON] et al. 's (2022) results, in our study, most participants faced some difficulties or required extra help to understand the immersive virtual reality system. This is probably partly explained by the fact that our sample presented a generally low background in virtual reality. This supports the recommendation of building a tutorial during the experience to support the end user. Another experiment developed with injured elite soccer players from the same English Championship showed a high VR experience, high standard in quality of graphics and sound, high level of immersion, and VR technology that was comfortable to wear and use [11]. Our findings partially corroborate these results, showing that these VR games may have great value as a rehabilitation tool. This methodology is expected to increase engagement (i.e., perceived usability, experience, immersive tendency, and presence) and provide a context for more goal-directed movements in the rehabilitation program based on the quality of the movement assessment and the game scores. This system's important feature provides real-time feedback, which encourages the player to complete the present game stage and motivates them to go to the following stages quickly [32]. Based on these results, we assume our technological solution for musculoskeletal injury rehabilitation based on VR gaming is a good tool to be used in the context of elite or amateur soccer. Secondly, VR games have been looked at from an individual perspective. The study of individual VR situations or exercises facilitates the analysis of the impact of each game individually. However, it limits the entire perspective of using several games, intra-connected, with different functional fitness purposes to compose a complete rehabilitation session.