STUDY DESIGN: A descriptive and correlation approach was used to assess joint motion. OBJECTIVES: Magnitudes and directions of sacroiliac motion were examined from three different upright postural conditions. SUMMARY OF BACKGROUND DATA: Evidence and clinical views suggest that sacroiliac motion available in the normal case is extremely small to nonexistent. METHODS: Systems for standardizing the three postures and the Metrecom skeletal analysis system (Metrecom, Faro Technologies, Inc., Lake Mary, FL) for acquiring coordinate data for selected skeletal landmarks. RESULTS: The complete sacroiliac oblique-sagittal motion that occurred between the right forward and left forward stride positions was 9 degrees (SD 6.5). The composite oblique-transverse motion was 5 degrees (SD 3.9). The motions in each plane were significantly different from zero. A joint mobility relationship existed between the hip and sacroiliac joints. CONCLUSION: The results demonstrate that substantial angular motion is possible at the sacroiliac joints.
STUDY DESIGN: A descriptive and correlation approach was used to assess joint motion. OBJECTIVES: Magnitudes and directions of sacroiliac motion were examined from three different upright postural conditions. SUMMARY OF BACKGROUND DATA: Evidence and clinical views suggest that sacroiliac motion available in the normal case is extremely small to nonexistent. METHODS: Systems for standardizing the three postures and the Metrecom skeletal analysis system (Metrecom, Faro Technologies, Inc., Lake Mary, FL) for acquiring coordinate data for selected skeletal landmarks. RESULTS: The complete sacroiliac oblique-sagittal motion that occurred between the right forward and left forward stride positions was 9 degrees (SD 6.5). The composite oblique-transverse motion was 5 degrees (SD 3.9). The motions in each plane were significantly different from zero. A joint mobility relationship existed between the hip and sacroiliac joints. CONCLUSION: The results demonstrate that substantial angular motion is possible at the sacroiliac joints.