In direct surface application of high frequency, where should the esthetician's finger be?

In the direct surface application of high frequency, the esthetician's finger should be on the electrode. This positioning is crucial for ensuring that the electrical current flows correctly during the treatment. When the esthetician's finger is in contact with the electrode, it creates a pathway for the current to travel through the electrode and directly into the client's skin, delivering the intended treatment effects.

Having the finger on the electrode allows the esthetician to maintain control of the treatment while also receiving feedback about the intensity of the current being applied. This is essential for both safety and effectiveness, as it helps to avoid any settings that could be uncomfortable for the client. In this method, it's important that no other contact points interfere with the flow of electricity, which is why the other response options, such as being on the client's skin, treatment table, or product, would not be suitable in this context.