Pelvic retroversion is associated with flat back and cam type femoro-acetabular impingement in young elite skiers - Todd, C.; Witwit, W.; Kovac, P.; Swärd, A.; Agnvall, C.; Jonasson, P.; Thoreson, O.; Swärd, L.; Karlsson, J.; Baranto, A. (Journal of Spine, 2016)