What do right and left bending images of the lumbar spine primarily demonstrate?

The right and left bending images of the lumbar spine are primarily used to demonstrate the range of motion of the lumbar spine. By obtaining bending images in both directions, healthcare professionals can assess how well the lumbar vertebrae can move and if there are any restrictions or abnormalities present. These images can reveal functional mobility, which is important in diagnosing conditions like lumbar disc herniation or degenerative disc disease.

The other options, while related to the lumbar spine, do not align as closely with what the bending images specifically show. Open intervertebral disk spaces relate more to standard radiographic views rather than bending positions. Zygapophyseal joints are typically visualized more effectively in specific oblique views rather than through bending. Lastly, the 'Scottie dog' is a mnemonic used to identify certain lumbar vertebrae in oblique projections, particularly for detecting spondylolysis, but it does not pertain directly to the evaluation of motion through bending images.