Background
Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve within fibrous tunnel on the medial side of the ankle. The most common cause of TTS is idiopathic. This is a retrospective study to define the lectrophysiological characteristics of idiopathic TTS.
Methods: We reviewed the medical and electrophysiological records of consecutive patients with foot sensory symptoms referred to electromyography laboratory. Inclusion of patients was based on clinical findings suggestive of TTS. Among them, patients with any other possible causes of sensory symptoms on the foot were excluded. Control data were obtained from 19 age-matched people with no sensory symptoms or signs. Routine motor and sensory nerve conduction study (NCS) including medial plantar nerve (MPN) using surface electrodes were performed.
Results: Twenty one patients (13 women, 8 men, 9 unilateral, 12 bilateral) were enrolled to have idiopathic TTS (total 31 feet). Tinel

Background
The medial plantar nerve (MPN) is a distal branch of the posterior tibial nerve, and various methods of nerveconduction study for MPN have been introduced so far. Hemmi et al described a new method (Hemmi's method) forrecording medial plantar sensory nerve action potentials (SNAPs), which is considered as a simple and reliable method formeasuring medial plantar SNAPs. This study was aimed to establish the normal values for the MPN conduction study amongKoreans and to compare the sensitivities of three different methods for MPN conduction study (Hemmi, Oh, and Saeed'smethod) in detecting evidence of peripheral neuropathy among diabetic patients. Methods: In 27 healthy subjects, MPN conductionstudy using Hemmi