Figure 4: Demonstration of the site to use for a local anesthetic to block the suspected joint and cutaneous afferents in the patient with knee pain. A) The upper band aid is over the site for the medial retinacular nerve, just distal to the vastus medialis, and the lower one is over the tender site of the infrapatellar branch of the saphenous nerve at the pes anserinus. B) The ink mark is the site of pain over the lateral retinacular nerve. If the patient complains of just medial knee pain, and there are two medial trigger points, just these are blocked and the patient is asked to walk and relate where any residual pain is located. Remember that the medial and lateral retinacular nerves overlap anteriorly, and usually both must be blocked to relieve anterior knee pain. C) Patient is seen squatting after the block relieved the knee pain.