ICU-Acquired weakness (ICU-AW) is a significant complication of critical illness. ICU-AW is common in patients with sepsis, systemic inflammatory response, and mechanically ventilated. It is estimated that around 50% of patients recovering from the primary illness remain in intensive care with characteristic muscle weakness. This leads to dependence on mechanical ventilation, prolonging costly intensive care hospitalization. The myopathy causes persistent functional impairment, endangering patients long after hospital discharge. Magnetic stimulation prevents inactivation atrophy of skeletal muscles, as demonstrated in the mobilized limb of rats. Transcutaneous magnetic stimulation of the quadriceps via the femoral nerve is a safe and painless method even when applied to humans. In patients with chronic obstructive pulmonary disease (COPD), quadriceps magnetic stimulation increased spontaneous contraction force compared to the control group and improved quality of life. Patients with COPD tolerate quadriceps magnetic stimulation well, as it does not affect oxidative stress in muscles but does increase the size of slow-twitch muscle fibers. In intensive care medicine, magnetic stimulation has been primarily used for diagnostic purposes in assessing diaphragm function, peripheral muscle strength assessment, and transcranial electrical stimulation as a diagnostic tool and therapeutic stimulation of brain cells. With the development of modern transcutaneous magnetic stimulators, the possibility arises for their use in intensive care medicine for therapeutic purposes such as preventing critical illness myopathy. To date, no research has been conducted on the use and effectiveness of magnetic stimulation of peripheral muscles in critically ill individuals. The aim of the study is to investigate the effect of Functional Muscle Magnetic Stimulation (FMS) on the development of ICU-AW.