Final answer:
The lumbar spine allows for flexion, extension, and lateral flexion, but is not designed to support rotational movements due to the orientation of the articular processes that provide stability and prevent injury.
Step-by-step explanation:
The movement that is not meant to occur in the lumbar section of the spine is rotation. While the lumbar spine allows for considerable flexion, extension, and lateral flexion, the orientation of the lumbar articular processes largely prohibits rotation. This is due to the alignment of the articular facets, which provide stability by restricting this movement and therefore preventing injury to the spinal column in this particular region.
The lumbar vertebrae are structured in such a way to support the body's weight and permit a range of movements required for various functions such as bending and twisting. However, due to the lumbar spine's design geared towards supporting weight and allowing flexibility for forward and sideways movement, its structure greatly limits rotational capacity to protect the integrity of the spinal column and the spinal cord it encases. This limitation in rotation helps mitigate the risk of disc herniation and nerve compression, which could lead to severe back pain or neurological issues.