Musculoskeletal pain as the effect of internal compensatory mechanisms on structural and functional changes in body build and posture in elite Polish sitting volleyball players

BACKGROUND: With the dynamic development of professional Paralympic sport, the prevalence of musculoskeletal pain and structural and/or functional disturbances in Para athletes constantly increases. The aim of the study was to evaluate the impact of internal compensatory mechanisms on selected aspects of body structure and function in elite sitting volleyball players. METHODS: The study included eighteen elite sitting volleyball players (male; n = 12, female; n = 6, age; 36.0 ± 6.1, body mass; 76.6 ± 16.1, body height; 179.3 ± 0.1) from the Polish national team. Retrospective and direct participatory observation methods were used in the study. NMQ-7 was used to assess the current prevalence and location of musculoskeletal pain. The evaluation of spinal curvature and pelvic inclination was performed using a non-invasive Medi Mouse method (Idiag M360) in three different trunk positions. All statistical analyses were performed using Statistica 13.3 software package. RESULTS: Lumbar hypolordosis was a predominant sagittal deviation of spinal curvature (n = 15;83%). Low back pain (LBP) and neck pain were the most frequent complaints (50%). Statistically significant differences in the values of thoracic kyphosis angle, pelvic inclination, and spine length (SL) in sagittal standing flexion and extension were found. However, there was no statistically significant difference in sagittal standing flexion for the lumbar lordosis angle with a simultaneous significant change in pelvic inclination (66.9°). Moreover, a tendency to interpenetration of relationships between variables that characterize (a) body structure and (b) function of the spine and musculoskeletal pain were observed. Shoulder pain correlated with SL (R = 0.6; p < 0.05) and body height (R = 0.5; p < 0.05). Pelvic inclination correlated with shoulder pain, LBP (R = 0.5; p < 0.05/R = 0.6; p < 0.01), and body trunk fat mass (R = − 0.6; p < 0.05). CONCLUSIONS: Trunk fat mass induces internal compensatory mechanisms to maintain optimal pelvic inclination and sagittal spinal balance. Furthermore, the level of pelvic mobility may determine musculoskeletal pain in Para athletes with lower limb impairment.