Goal with Nerve Stimulator?
The femoral nerve innervates a number of muscle groups. A visible or palpable twitch of the quadriceps muscle (patella twitch) at 0.2-0.5 mA current is the optimal response.
The most common response to nerve stimulation with this technique is twitch of the sartorius muscle. This results in a band-like contraction across the thigh without movement of the patella.
It should be kept in mind that sartorius muscle twitch is not reliable because the branches to the sartorius muscle may be outside the femoral sheath. When the sartorius muscle twitch occurs, the needle is simply redirected laterally and advanced several mm deeper.