MYOELECTRIC ACTIVITY AND PERIPHERAL MUSCLE OXYGENATION DURING FUNCTIONAL TESTING IN INDIVIDUALS WITH SYSTEMIC ARTERIAL HYPERTENSION: A CASE-CONTROL STUDY
KEYWORDS: muscles; oxygenation; functional status; arterial hypertension.
ABSTRACT
Systemic arterial hypertension (SAH) is a multifactorial condition that leads to endothelial dysfunction and vasoconstriction, resulting in reduced oxygen delivery to body tissues. Consequently, there is a disproportionate increase in the neural respiratory drive directed to the muscles responsible for breathing. Simultaneously, the increased demand placed on respiratory muscles may reduce the blood flow available to locomotor muscles, exacerbating peripheral dysfunction and worsening the symptoms of SAH. In this context, the present study aims to evaluate the electrical activity of respiratory (parasternal intercostal and scalene) and peripheral (quadriceps femoris and gastrocnemius) muscles in hypertensive individuals during a functional test, comparing them with healthy controls. This is a cross-sectional, case-control study conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Participants will be recruited from the Physiotherapy Teaching Clinic at FACISA and/or from Primary Health Units in Santa Cruz, RN, and data collection will take place at the Human Movement Laboratory at FACISA. Muscle electrical activity will be assessed using surface electromyography (EMG), while muscle oxidative metabolism will be analyzed using near-infrared spectroscopy (NIRS). Participants will be divided into an experimental group (hypertensive) and a control group (healthy individuals). At study enrollment, participants will undergo a structured physiotherapeutic evaluation. Subsequently, the skin will be prepared, and EMG and NIRS electrodes will be positioned. Measurements will be taken at rest (5 minutes) and during the six-minute walk test (6MWT). After the test, a 60-second recovery period will be performed, followed by reassessment of vital signs. This study is expected to characterize the electrical activity of respiratory and peripheral muscles in hypertensive individuals, contributing to a better understanding of the effects of SAH on neuromuscular control and blood flow distribution during physical exertion.