Final answer:
Most people with PLL ossification commonly experience back pain, numbness in the limbs, and difficulty walking due to nerve compression caused by the ossified ligament in the spinal canal.
Step-by-step explanation:
The question asks about the three common symptoms experienced by most people with PLL ossification. PLL stands for posterior longitudinal ligament, and its ossification can lead to neurological symptoms due to compression of spinal nerves or the spinal cord itself. The correct answer, based on the common spinal symptoms associated with this condition, would be A) Back pain, numbness in the limbs, and difficulty walking. These symptoms occur because the ossified ligament can impinge on the neural elements in the spinal canal, leading to pain and neurological deficits.
Back pain occurs as a result of the spinal column's altered mechanics and potential nerve root irritation. Numbness in the limbs is indicative of nerve compression, which can also manifest as tingling or a pins-and-needles sensation. Difficulty walking can present due to both the pain and the impaired nerve function affecting muscle strength and coordination. These symptoms are more specific to spinal pathology, unlike the symptoms listed in the other answer choices, which relate to different medical conditions.