Normative Values for Peripheral Muscle Strength in Critical Patients and Healthy Individuals

Muscle strength is an important indicator of overall health and is a factor that has been associated with increased mortality in critical patients. Its measurement must be reliable and reproducible to ensure a quality outcome for clinical applicability. Recently, the use of digital handheld dynamometers in intensive care has gained support; however, analysis becomes challenging due to the absence of standardized reference equations for the Brazilian population. The aim of this study is to develop reference equations for the Brazilian population and define specific cutoff points for men, women, healthy individuals, and critical patients.

For this 3-year observational study, the population will consist of adult and elderly individuals of both sexes; for the healthy sample, patients without barriers to the assessment of peripheral muscle strength will meet the inclusion criteria, specifically, areas with wounds/dressings, burns, segments with fractures, or immobilization devices, while, for the critical patient population, the sample will comprise patients who are hospitalized in the Intensive Care Unit (ICU). In the case of assessing healthy participants, an evaluation of the musculoskeletal system will be conducted to measure muscle strength (handgrip dynamometry and peripheral hand held muscle dynamometry). Regarding critical patients, if the participant meets the criteria, the evaluation protocol will be carried out, which includes peripheral muscle strength assessment (Medical Research Council scale, Hand Dynamometer, and the Hand-Held Dynamometer) and the patient's mobility status (ICU Mobility Scale). Daily screening will take place in the ICU, with eligibility assessed during the screening process. If eligible, secondary data related to the critical condition will be extracted from the participant's medical records, including anthropometric data, sociodemographic information, neurological and cardiovascular assessments, current medications, and laboratory test results. The participant's hemodynamic and respiratory stability will be monitored using a multiparameter monitor, recording data such as blood pressure, heart rate, peripheral saturation, and respiratory rate. A cardiorespiratory and clinical safety checklist will also be completed prior to conducting tests for all patients, regardless of whether they are using mechanical ventilation. The instruments used for assessment the muscle strength are the Digital Hand Dynamometer (Saehan Corporation®, DHD-1) and the Hand Held Dynamometer (HOGGAN SCIENTIFIC LLC, microFET2).