When stimulating the posterior tibial nerve at the ankle, how can stimulation be confirmed?

Recording a response from the popliteal fossa is the correct method to confirm stimulation of the posterior tibial nerve at the ankle. This response signifies that the nerve has been adequately stimulated and that the electrical signal is traveling along the nerve pathway. When the posterior tibial nerve is stimulated, muscle responses can be recorded distally, and observing a response in the popliteal fossa provides direct evidence that the nerve has conducted the stimulus effectively.

Other methods may not directly confirm that the nerve has been stimulated correctly. For instance, recording a cortical response at Cp4 specifically looks for central nervous system activity and doesn't guarantee that the peripheral nerve is conducting the stimulus. Simply turning the stimulator up to read 20mA does not ensure effective stimulation, as the required intensity can vary between individuals, and excessive current can lead to muscle contractions without nerve stimulation. Lastly, reducing the impedance of the stimulating electrodes can improve the effectiveness of stimulation but doesn’t directly confirm that the nerve is responding.