Final answer:
The most ergonomic approach for administering an ultrasound-guided lateral popliteal sciatic nerve block (SNB) is for the patient to be in a prone position.
Step-by-step explanation:
The most ergonomic approach for administering an ultrasound-guided lateral popliteal sciatic nerve block (SNB) is to place the patient in a prone position. In this position, the patient lies face down with their upper limbs, including palms, touching their sides and lower limbs touching at the sides.