What does the examiner specifically block during the McKenzie Side Glide test?

During the McKenzie Side Glide test, the examiner specifically blocks the patient's shoulder against the thorax. This positioning is crucial because the aim of the test is to assess the patient's response to lateral bending or side gliding of the lumbar spine while controlling for movement above by stabilizing the shoulder.

By blocking the shoulder, the examiner isolates the movement of the lumbar spine, allowing for the identification of any asymmetrical patterns or pain that may indicate specific pathologies in the spine or related structures. This helps determine how the spinal segments are functioning and can guide subsequent treatment approaches by identifying which movements provoke symptoms or are beneficial.

In contrast, blocking other areas like the lumbar region, hips, or knees would not effectively isolate the lumbar movements being evaluated in this test and could lead to ambiguous findings. Thus, the focus remains on the thoracic region to ensure a clear assessment of lumbar lateral flexion dynamics.