Final answer:
In lumbar spine flexion, the inferior facets of the superior segment glide superiorly and anteriorly, the lumbar disc is compressed posteriorly, and the intervertebral foramen decrease in size. This motion decreases, rather than increases, the lumbar lordosis.
Step-by-step explanation:
With lumbar spine flexion, the following statements can be evaluated:
- A) This increases the lumbar lordosis. - This is incorrect. Lumbar spine flexion actually decreases lumbar lordosis because it involves bending forward, which flattens the natural curve of the lower back.
- B) The inferior facets of the superior segment glide superiorly and anteriorly. - This statement is true. During lumbar flexion, the inferior articular facets of the superior vertebra move upwards and forwards relative to the facets on which they articulate.
- C) The lumbar disc is compressed posteriorly. - This statement is true. When bending forward, the anterior portion of the intervertebral disc is compressed, while the posterior part expands.
- D) The intervertebral foramen close down or decrease in size. - This statement is also true as flexion of the lumbar spine can lead to a decrease in the size of the intervertebral foramina, potentially compressing the exiting nerves.