Sensitivity, low-frequency filter, high -frequency filter, sweep speed, duration of pulse, rate of pulse, and the machine used were not specified.

This study was performed in the supine position. The forearm, wrist, and hand were stabilized with Velcro on a comfortable board.

Following the orthodromic method [1], the inching test was performed on sensory fibers of the median nerve in digit III (Fig. 1). The sensory potential was recorded with a bipolar fixed distance (2.2 cm); the surface electrode moved centimeter by centimeter from a point 4 cm proximal to the distal wrist crease to a point 6 cm distal to the distal wrist crease, providing 11 measurements (R1–R11). The active electrode (A) was placed proximal to the stimulating cathode (−); the reference (R) was placed distally. The ground (G) electrode position was not specified in the report; the figure shows the ground electrode placed on the palm.

The median nerve was stimulated by ring electrodes to digit III (S). The active cathode (−) was placed at the proximal interphalangeal joint of digit III; the anode electrode (+) was placed distally at the distal interphalangeal joint. The current parameters were not specified in the report.

Peak latency (ms) was measured from the onset of the stimulus to the peak of the negative deflection of the sensory nerve action potential (SNAP) with an accuracy of 0.02 ms. The conduction delay per centimeter (CD/cm) is the time necessary for the nerve impulse to travel a distance of 1 cm between two adjacent recording points. The normal CD/cm (nCD/cm) was the mean CD/cm calculated from four segments outside the area of compression (segments 1–4, 9, 10). Nerve segments 5–8 were considered to be inside the carpal tunnel. The segment with the highest CD/cm was called the maximal CD/cm (MCD/cm). Amplitude (μV) data were not addressed (only the mean amplitude value of the SNAP recorded from digit III was reported; it was 68 ± 23 μV). Skin or room temperatures were not reported. Normal values (Table 1) were obtained from 80 dominant wrists of 80 control subjects (51 women and 29 men, age range 22–68 years, mean age 42 years); pathological values (Table 2) were recorded from 100 wrists of 85 patients (63 women and 22 men, age range 25–83 years, mean age 46 years) with mild carpal tunnel syndrome (CTS).