RESUMO
The mechanism of muscle damage in critically ill patients mainly includes microcirculation disorder, changes in cells and metabolism, inflammation, increased myoprotein breakdown in muscular atrophy, and inactivation of ion channels. Manual muscle testing is the most commonly used muscle strength measurement for critically ill patients, which is simple and economic, but subjective, being not accurate and sensitive in evaluating muscle weakness of patients and distal limb function. Neuroelectrophysiological testing is safe, non-invasive, simple and objective, but it requires specialized equipment and trained qualified professionals, high medical costs, time and effort consumption, and lack of specificity. Dynamometer is a simple, objective, convenient and inexpensive assessment method, which has a good reliability and validity in application in the critically ill patients, but it is not widespread in China.