Evaluation of Sit-to-stand Test in Patients With Cystic Fibrosis and Matched Controls.

Introduction: In recent years, since the discovery of the cystic fibrosis (CF) transmembrane conductance regulator gene in human skeletal muscle, there appears to be growing interest in the measurement of muscle function in CF. One of the most used test in other chronic pulmonary diseases is the Sit-to-Stand test (STS) which consists of simply getting up from a chair. Although the main result of the STS test is the time developed during the task, the velocity and power generated during the task are considered very important variables to detect the functional decline. However, from our knowledge, no study has previously analyzed the differences in time, velocity and muscle power developed during the STS test in patients with CF and their respective healthy controls. Objectives: To compare the values gained from handgrip strength, walking speed and STS test (time, velocity, and muscle power) in a group of patients with CF and their respective healthy controls, and to analyze if these differences (if any) are associated with lung function in patients with CF. Methods: Cross-sectional study with a sample of 60 participants (30 patients diagnosed with CF and 30 healthy subjects) between 18-65 years old. The STS test will be measured through slow-motion video recording with a smartphone device (240 images per second) which will report the time, velocity and power generated during the test. Walking speed and handgrip strength will be also measured. Additionally, the relationship between the variables obtained during the test and the lung function of patients with CF will be analized.