Body Posture and Low Back Pain in Amateur Tennis Players: A Cross-Sectional Observational Study

Background: Quantitative assessment of postural parameters in all anatomical planes may help clarify the potential role of posture in the pathomechanism of low back pain (LBP) in tennis players and support the development of preventive and rehabilitation strategies. This observational cross-sectional study aimed to compare selected pelvic and spinal posture parameters of amateur tennis players with LBP, amateur tennis players without LBP, and physically active controls without LBP who did not participate in asymmetric sports. Methods: The study included 116 participants (52 women and 64 men): amateur tennis players with self-reported tennis-limiting LBP within the previous 6 months, amateur tennis players without such a history, and physically active controls who did not participate in asymmetric sports and were free of LBP. Spinal and pelvic posture parameters were assessed using the DIERS Formetric 4D rasterstereography system. Group comparisons were performed using ANOVA or the Kruskal–Wallis test, as appropriate. Results: Across most analysed body posture parameters, no clear and consistent between-group differences were detected in this sample. Among men, significant between-group differences were observed in pelvic rotation and maximum right vertebral rotation. Men in the TBP (Tennis Back Pain) group showed a mean left-sided pelvic rotation compared with a mean right-sided rotation in those in the TNBP (Tennis No Back Pain) group, and lower maximum right vertebral rotation than men in the PAC (Physically Active Control) group. Among women, a significant between-group difference was observed for coronal imbalance, with higher left-sided values in the TBP group than in PACs. No consistent between-group differences were found across the remaining pelvic and spinal parameters. Conclusions: In this sample of amateur tennis players, static body posture parameters showed limited and non-uniform associations with LBP. The observed differences were selective and of uncertain clinical relevance, and the analyses did not reveal a single consistent postural pattern clearly associated with LBP in this sample.