Subjects were treated once time. The technique consisted in the application of a square wave biphasic electrical current, with 10 Hz frequency, with 250 μs pulse width and the maximal torelable intensity to cause an exacerbated muscle contraction during ten seconds with a rest period of another ten seconds y total number of ten times. The subjects were lying in lateral decubitus. The common peroneal nerve was located with ultrasound (cross section) near to the peroneal head. After, an acupuncture needle (0,30mm x 30mm) was inserted in a long axis approach until the perineurium of the common peroneal nerve (in close proximity)

Subjects were treated once time. The subjects were lying in lateral decubitus. The common peroneal nerve was located with ultrasound (cross section) near to the peroneal head. After, an acupuncture needle (0,30mm x 30mm) was inserted in a long axis approach until the perineurium of the common peroneal nerve (in close proximity). The needle remains in this location during 200 seconds without any electrical current.

It´s an intervention of physiotherapy

The Cumberland ankle instability tool (CAIT) is a questionnaire that consists of 9 items, the maximum score of the questionnaire is 30 points, the lower the score obtained, the more severe the functional instability of the ankle. The Spanish version of the CAIT has high internal consistency (Cronbach's α00.766) and reliability (intraclass correlation coefficient 0.979, 95 % confidence interval (CI) 0.958-0.990).

The BBS is a platform designed to measure and record an individual´s ability to maintain stability under dynamic stress. It calculates a medial-lateral stability index (MLSI), anterior-posterior stability index (APSI), and an overall stability index (OSI) with reliability estimates of R= 0.92 (OSI), R = 0.89 (APSI), R= 0.93 (MLSI).