The effect of lumbopelvic region rotation relative flexibility on thorax–pelvis and pelvis–femur coordination during walking

Abstract

BackgroundLumbopelvic region rotation relative flexibility (LRRF), which is defined as lumbopelvic region that is relatively less stiffness than the hip region, is associated with low back pain (LBP) symptoms. However, how LRRF is influenced by lumbopelvic region motion during walking is unclear. Research questionWhat is the influence of LBP and LRRF on coordination patterns of the thorax, pelvis, and femur during walking? MethodsThe presence of LRRF was determined based on whether the lumbopelvic rotation occurred in the first 50% of knee flexion or hip external rotation movement. Participants with LBP and LRRF were classified into the LBP group. Participants with LRRF but without LBP were classified into the early pelvis rotation (ROT) group, and those without LBP and relative flexibility were classified as controls. The thorax–pelvis coordination and pelvis–femur coordination during the stance cycles were calculated from the segmental angles obtained by three-dimensional motion analysis using a modified vector coding technique. ResultsIn the sagittal plane, the thorax–pelvis coordination of the LBP group showed more anti-phase patterns at both the early stance and midstance compared with controls and the ROT group. In the sagittal and horizontal planes, pelvis–femur coordination of the LBP and ROT groups showed more in-phase patterns during the early stance and midstance compared with controls. SignificanceRegardless of LBP, the presence of LRRF alters the intersegmental coordination during walking. In individuals with LRRF, stiffness of the hip may increase during walking. People who have LRRF without LBP may develop LBP in the future, and it is important for prevention to identify these differences in kinematics during walking.