Kinematics characteristics of the spine and pelvis are one measure proposed to assess lumbar dysfunction. To extent our knowledge about this matter we described the relationship between the orientation of the sacrum, in the sagittal plane, at upright position and the differential lumbar spine and pelvis range of flexion at the toe touch position in free-pain subjects.

Position and motion measurements were recorded by an electrogoniometer. Individuals (n=39), were divided into two groups according to whether they have either pelvis (pelvis -group, n=18) or lumbar spine (spine-group, n=21) dominant movements during flexion. The mean age was 23,67±4,94 years (range18 to 33 years) in the pelvis-group, and 22,55 ± 2,70 years (range 19 to 27 years) in the spine –group. The range of pelvis flexion was significantly greater in the pelvis group than in the spine group, the range of lumbar spine flexion was significantly greater in the spine group than in the pelvis group (α≤.001); however, no differences were found in the range of back flexion (combined lumbar spine and pelvis motion) between the two groups. In the pelvis group the sacrum was significantly more horizontal than in the spine group (α≤.001). In the pelvis-group very strong correlation between sacrum orientation and the maximum range of pelvis flexion was found (r =0, 61). In the Spine group, sacrum orientation showed a negative strong correlation with the maximum range of spine flexion (r= − 0, 71). These results suggest the influence of the individual morphology on the lumbo-pelvic patterns of movements.