Peripheral muscle strength assessment and exercise capacity in patients with Adolescent Idiopathic Scoliosis

Abstract

Adolescent idiopathic scoliosis (AIS) accounts for 80% of all idiopathic scoliosis, with an estimated prevalence of between 2% and 4% of all adolescents aged 10 to 16 years. In addition to respiratory dysfunction, patients with AIS present decreased exercise capacity regardless of the severity of the disease. There are reports in the literature about nutritional changes and generalized muscular dysfunction in these patients that may influence the exercise capacity. Objectives: To assess the peripheral and respiratory muscle strength, body composition, exercise capacity and lung function in individuals with AIS and healthy adolescents. In addition to assessing in patients with AIS correlations between peripheral muscle strength and exercise capacity, body composition, respiratory muscle strength, lung function, and spinal angulation. Methodology: A cross-sectional study will be performed with 20 patients with AIS and 20 healthy individuals. Participants will be submitted to the following evaluations: anthropometry and body composition, muscle strength, cardiorespiratory fitness, spirometry and manovacuometry. The muscular function will be evaluated in an isokinetic dynamometer according to previously described methods. Body composition will be determined by bioelectrical impedance. Cardiorespiratory fitness will be assessed using the Incremental Shuttle Walking Test (ISWT). The expired gases during the test will be analyzed by a portable gas analyzer. Spirometry and respiratory muscle strength will be performed according to the recommendations of the Brazilian Society of Pulmonology and Phthisiology. Statistical method: Data will be evaluated descriptively and presented as mean and standard deviation or as median (interquartile range). To compare the means or medians of the variables between the patients and healthy individuals will be used the unpaired t test or Mann-Whitney, respectively. The correlations between the studied variables will be evaluated by the Pearson or Spearman correlation coefficients. The alpha error probability will be set at 5% for all analyzes. (AU)