Which of the following symptoms might be assessed during the McKenzie Side Glide test?

The McKenzie Side Glide test is primarily utilized to assess and differentiate various types of low back pain, specifically by evaluating how movements affect symptoms. This test is designed to examine the influence of lateral movements of the spine on existing pain and is integral to the McKenzie method of physical therapy, which focuses on mechanical assessment and treatment of musculoskeletal disorders.

When a patient undergoes this test, the therapist aims to identify if lateral glide movements of the lumbar spine either increase or alleviate low back pain, which can help in discerning the underlying cause of that pain. The symptoms assessed during this test are closely tied to the lumbar region, making low back pain the most relevant symptom to evaluate.

While other mentioned symptoms, such as numbness in the legs, neck stiffness, or shoulder pain, may be important to assess during a comprehensive evaluation of the patient, they are not directly associated with the specific mechanics and focus of the McKenzie Side Glide test. The test strictly addresses conditions related to the lumbar spine and its influence on low back pain, thus making it the correct answer in this context.