Final answer:
The most ergonomic approach for administering a popliteal SNB involves placing the patient in a sitting or kneeling position.
Step-by-step explanation:
The most ergonomic approach for administering a popliteal SNB involves placing the patient in a sitting or kneeling position. This position allows for better access to the popliteal fossa, the area behind the knee, and provides a more comfortable and stable position for the patient during the procedure.