There is no significant disagreement about the major common entrapment neuropathies, such as carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow, and peroneal neuropathy at the knee. In contrast, there is a group of entrapment syndromes about which there is major disagreement, including whether or not they even exist. There are other entrapment syndromes about which clinical questions arise on a regular basis, and which are the subject of this discussion. These include thoracic outlet syndrome, radial tunnel syndrome, ulnar nerve entrapment at the arcade of Struthers, piriformis syndrome, and tarsal tunnel syndrome.