Subjects in MV will be included, divided into 3 groups: (a) Control Group (CG), (b) Stimulation of Quadriceps (Quadriceps Group - QG), (c) Stimulation of Diaphragm (Diaphragm Group - DG). The QG and DG patients will receive consecutive daily electrical stimulation sessions at specific points from the first day of randomization until ICU discharge. Respiratory and peripheral muscle strength, MV time, length of hospitalization and functional independence score (the Functional Status Score-ICU) will be recorded.

Objective: Evaluate the effectiveness of the Neuro Muscular Electrical Stimulation therapy in quadriceps versus diaphragm subjects on mechanical ventilation (MV). Subjects in MV will be included, divided into 3 groups: (a) Control Group (CG), (b) Stimulation of Quadriceps (Quadriceps Group - QG), (c) Stimulation of Diaphragm (Diaphragm Group - DG). The QG and DG patients will receive consecutive daily electrical stimulation sessions at specific points from the first day of randomization until ICU discharge. Respiratory and peripheral muscle strength, MV time, length of hospitalization and functional independence score (the Functional Status Score-ICU) will be recorded.

Inclusion Criteria:

• Age of 18 years or more
• 24 hours of MV or more

Exclusion Criteria:

Hemodynamic instability, pregnancy, body mass index(BMI) >35 kg/m2, history of neuromuscular disease at admission, brain death, diseases with systemic vascular involvement, bone fractures, use of an internal or external fixator, skin lesions, end-stage cancer, use of pacemakers, spinal injuries, or inability to receive an Medical Research Council score because of the cognitive state.