Does the demand for asymmetric functional lower body postures in lateral sports relate to structural asymmetry of the pelvis?

Pelvic asymmetry has been thought to alter body mechanics and result in increased strain on bony and soft tissues possibly producing asymmetrical skeletal adaptations. The purpose of the present study was to determine if there is a greater prevalence of pelvic skeletal asymmetry in athletes who participate in a sport that requires a lateral dominance combined with increased spinal flexion and rotation. This is a descriptive laboratory study using a cross-sectional design. Sixty healthy female university age elite athletes and non-athletes participated in the study. The height and width of the anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) were measured using an electromagnetic tracking device with stylus. Using these measures a pelvic asymmetry ratio (PAR) was calculated for each athlete based on the difference in slope between the two ASIS and between the two PSIS. PAR was first assessed as a continuous variable to determine any differences in range of asymmetry between groups. All athletes were then assessed for prevalence of asymmetry as defined by a PAR score greater than 0.05. The results showed that there was a significant group effect in the magnitude and prevalence of asymmetry, with the lateral dominant group having significantly more of both. This study demonstrates that potentially there is an association between the asymmetrical nature of lateral dominant sports and pelvic skeletal asymmetry. However, there are possibly two confounding variables in age of initial participation and presence of low back pain that require further exploration. (C) 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.