Análise da atividade eletromiográfica e força muscular do complexo do ombro em indivíduos com e sem dor subacromial

Abstract

Background: Changes in muscle activation and force production in the scapulohumeral joint are frequently associated with Subacromial Pain Syndrome (SPS). However, studies evaluating aspects related to strength relations, electromyographic amplitude and activation time of the scapular stabilizing muscles in these subjects are still scarce. Objective: To compare muscle strength and electromyographic activity of the shoulder muscles between asymptomatic individuals and individuals with SPS. Methods: A cross-sectional study was carried out with 70 subjects of both sexes, aged between 35 and 60 years, diagnosed with SPS (n=35). These were recruited and compared with asymptomatic subjects (n=35), matched for age, weight, height, gender, limb dominance and level of physical activity. Muscle strength was measured with a digital dynamometer and electromyographic data were verified using a signal conditioning module. Results: Reduction of medial and lateral rotation strength and shoulder flexion was found in the SPS group compared to the asymptomatic subjects. The serratus anterior muscle in the SPS group showed decreased activity at all evaluated humeral elevation angles and a delay in the onset of activation time during shoulder elevation when compared to the control group. Conclusion: The strength of the flexors, lateral and medial rotators of the shoulder is reduced in patients with SPS. Furthermore, there is significant dysfunction of the serratus anterior muscle in these subjects, with reduced electromyographic amplitude and delayed activation time. These factors should be considered in the rehabilitation process of these individuals.