Experimental study that has how to compare the efficacy between conventional rehabilitation, transcutaneous electrostimulation or early mobilization to reduce the time needed to reverse the muscle weakness evaluated by the muscle strength scale of the MRC in patients with a clinical diagnosis of intensive care unit acquired weakness in the (ICUAW).The ambit of realization is a medical-surgical ICU of a general acute hospital (26 beds). A randomized controlled, uni-centric design was used. The interventions are divided into three groups namely; group 1 (control group) receiving standard or usual rehabilitation (GR-STD); group 2 receives transcutaneous electrostimulation (GR-TEE) and group 3 that consists of an early mobilization protocol (GR-EM). The main outcome variable of the study is the time, in days and sessions of treatment, to reverse the ICUAW.

Study hypothesis: the time to revert the intensive care unit acquired weakness is less when applying an early mobilization protocol or transcutaneous electro-nervous stimulation compared with the usual or standard rehabilitative treatment.

Ethical considerations: The research protocol was presented and approved by both the Ethics Committee and the Teaching and Research Committee of our institution. The informed consent of each subject included in the study was obtained.

Sample size and study power: a sample size was defined in 18 subjects (6 subjects per intervention group). The estimation of the sample was calculated for a one-way ANOVA where a minimum difference of 2 sessions was established between the treatments, assuming a standard deviation of 1.8 sessions, an alpha error of 5% and a power of 80%.

Statistical methods: the numerical variables will be presented as mean and standard deviation or median and interquartile range according to the presented distribution. The categorical variables will be presented by frequency and percentage.

For the comparison of continuous variables, Student's t test for independent samples or the Mann-Whitney U test will be used according to the presented distribution and for the categorical variables the Chi² test or the Fisher exact test will be used according to the conformation of the crossed table. The Shapiro-Wilk test will be used to evaluate whether the distribution presented by the numerical variables fits a normal distribution. Equality of variances was assessed by the Levene´s test.

The comparison of the time to reach an smuscle strength scale of the MRC ≥ 48 between the groups with different interventions will be used the one-way ANOVA test or the Kruskal-Wallis test as appropriate. For post hoc analysis, the pairs-comparison test of Games-Hollew or Dunn's-Bonferroni will be used for ANOVA or Kruskal-Wallis, respectively, when they reach statistical significance.

Inclusion Criteria:

• subjects over 18 years of age,
• admitted to the ICU who have received invasive mechanical ventilation for a period longer than 24 hours
• clinical diagnosis of ICUAW (MRC-mss <48 measured over two consecutive days).

Exclusion Criteria:

• subjects who presented a body mass index> 35 (kg/height x height)
• presence of edema that prevents the realization of NMES at the time of diagnosis of ICUAW (assessed by the absence of visible contraction
• pregnant women
• subjects with pacemakers
• subjects with injury of the central and / or peripheral nervous system (with motor sequelae)
• previous neuromuscular disease
• limitation of the movement of any extremity due to orthopedic or traumatological causes
• presence of a previous cognitive disorder that impedes the understanding of rehabilitation interventions
• a value of the index of Barthel less than 35 points at admission
• subjets who refused to give informed consent.

the person in charge of performing the statistical analysis was blind, by coding the interventions in the database.