Use of electrical stimulation devices in strengthening the quadriceps femoral muscle

Transcutaneous muscular electrical stimulation is widely used as a valid aid in rehabilitation protocols after cruciate ligament reconstructive surgery and other situations characterised by muscular hypotrophy with a consequent loss of muscular strenght. From a review of the bibliography, no attention appears to have been focused on the question of whether transcutaneous electrical stimulation can prevent deterioration in muscular performance resulting from an interruption in athletic training. The aim of this study was to evaluate whether electrical stimulation can, augment muscular strenght in non-professional athletes during a five-week period in which the subjects enrolled in the study did not take any kind of physical exercise. The fourteen athletes who agreed to take part in this study used two of the most commonly used apparatus for electrical stimulation: the 'simplex' and the 'compex'. Each subject was randomly assigned to one of the two devices by drawing names. The following protocols were used; For the Compex: stimulation frequency (75 Hz); duration of tetanic contraction (4 sec); duration of decontraction (19 sec); decontraction frequency (4 Hz); total duration of training (18 min). For the Simplex: stimulation frequency (60 HZ); duration of tetanic contraction (7 sec); duration of decontraction (13 sec); total duration of training (20 min). The frequencies used for both training protocols were deemed to be capable of stimulating type II fibres (FT). All athletes were tested on two consecutive days before the start of the protocol and at the end of the five-week period using 'dyna biopsy' and an 'ergometer'. The results of this study show that the use of electrical stimulators can replace active training as a means of increasing muscle strenght, without any loss of strenght. On the contrary, a striking increase in muscle strenght was observed in some subjects who took part in this study.