Final answer:
The injection of anesthetic in a popliteal SNB should occur below the bifurcation of the sciatic nerve.
Step-by-step explanation:
The injection of anesthetic in a popliteal SNB should occur below the bifurcation of the sciatic nerve. The popliteal region is located in the back of the knee, and the sciatic nerve divides into two branches below this region. In order to target the nerve effectively, the injection should be below the point of division.