## 4 Discussion

Table 4: _Cont._Another important variable analyzed in our study was the time of disability, as we assumed that it has an effect on the development of the habitual posture in line with the anatomical (biomechanical) pattern. In the group of Polish goalball players studied, the average age of the athletes and the time of disability were similar. Furthermore, the average training experience oscillated around 6 years; thus, the development of the players' posture most often took place in the absence of vision or impaired vision and was related to the time of disability, which was confirmed by the correlation of the variable of time of disability with THA in standing and trunk flexion. [PERSON] et al. [26], in a study of visually impaired athletes, showed an overall rightward inclination of the body, a forward positioning of the head, and a forwardly inclined pelvis, followed by a flexed knee and a valgus ankle aligned in dorsiflexion position, which corresponds with our qualitative analysis of the posture of elite goalball athletes, indicating the presence of an internal compensatory mechanism that is independent of sports training and is due to the specificity of the disability. This thesis was confirmed by the research of [PERSON] et al. [27], which concludes that wheelchair use is a sufficient risk factor for shoulder pain regardless of sport, as the incidence was comparable to the control group. This hypothesis confirms our hypothesis about the existence of an internal compensatory mechanism in the posture of people with visual impairments, which is related to the specificity of the disability. It should also be noted that among the goalball players studied, lumbar abnormalities (hyper and hypolordosis) were the most common, and hyperkyposis co-occurred with hyperlordosis each time, which may reflect the adaptation of body posture to the specifics of goalball training. This hypothesis corresponds with the theses of a systematic review and meta-analysis among non-disabled athletes, where the authors showed that the specificity of sports training is the most common variable that influences variability in spinal curvature and posture [6]. Most studies among able-bodied athletes have revealed a directly proportional relationship between spinal curvature abnormalities or disorders and sport-specific training [28; 29; 30; 31]. At the same time, there are no studies in the available literature on the assessment of spinal curvature in the sagittal plane among blind athletes/goalball players. Therefore, it can be estimated that the practice of sport by people with disabilities, the associated training loads, and the sport-specific movements/exercises induce biomechanical adaptations in posture and postural control [32], as has been shown in other disability groups [3]. The authors indicate that poorer postural control is associated with an increased risk of lesions, especially in the ankle joint [33]. According to [PERSON] et al. [34; 35; 80; 81; 82; 83; 84; 85; 86; 87; 88; 89; 90; 91; 92; 93; 94; 95; 96; 97; 98; 99; 100; 101; 102  
of the body posture to the specific sports training of the goalball players, which may contribute to musculoskeletal pain. We hypothesize that the occurrence of musculoskeletal pain is more a consequence of the goalball player's posture, which is influenced by the alignment of the anatomical curvature of the spine and the absence of vision (anatomical and biomechanical integration). The pattern of posture developed under altered biomechanical conditions is primarily generated by an internal compensatory mechanism, and this contributes to the musculoskeletal complaints indicated by athletes. In view of this thesis, compensatory motor training in static and dynamic conditions should be recommended for goalball athletes. Therefore, training aimed at integrating proprioceptive sensory perception and body awareness, especially in the habitual standing position, is recommended.