Where is the acupuncture point Yao Yan located?

Yao Yan, also known as the "Eye of the Lumbar Region," is an important acupuncture point used in various treatments, particularly for back pain and lumbar issues. It is located 3.5 cun lateral to the lower border of the fourth lumbar vertebra (L4). This site is chosen because it corresponds to the area of the lumbar spine, which often correlates with patterns of tension or pain in that region.

Understanding this point's relation to L4 is crucial for practitioners, as accurate localization of acupuncture points facilitates effective treatment. The anatomical landmarks used for measuring cun in acupuncture serve to ensure that practitioners can reliably find Yao Yan in various patients, regardless of their body size.

The other options pertain to different acupuncture points or areas not related to Yao Yan. For instance, the first option describes a point adjacent to L1, which is not Yao Yan. The second option references an area on the shoulder, related to different structures and conditions. The last option identifies a location on the hand, which is also irrelevant to Yao Yan. Understanding the specific location of Yao Yan helps practitioners deliver targeted care to treat lumbar and lower back issues effectively.