Reliability and physiological analysis of an isometric test of muscular fatigue localized

Author(s)

Larissa Rodrigues Souto

• Document type: Master's Dissertation
• Press: Presidente Prudente. 2018-08-27.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências e Tecnologia. Presidente Prudente
• Defense date: 2018-06-28
• Advisor: Carlos Marcelo Pastre

Abstract

Introduction: Reliable physical tests, capable of identifying a real change in performance from physiotherapeutic interventions and/or physical training, are extremely important for the prescription of physical exercises. Its application provides individualized parameters of muscular performance, allowing an adequate implementation of loads during training and/or rehabilitation dynamics. In addition to the application of such tests, evaluating the metabolic demand during its execution is extremely important in clinical practice, providing physiological parameters for both evaluation and implementation of load dynamics. Objectives: To verify the intra- and inter-rater reliability of an isometric muscle fatigue test (IMFT) of the dominant lower limb quadriceps performed on the isokinetic dynamometer and to analyze the metabolic demand required during its execution. Methods: The study was divided in two phases, the first one referring to the analysis of intra- and inter-rater reliability of the IMFT and the second one in relation to the analysis of its metabolic demand. The first phase of the study consisted of three sessions: familiarization, test and retest. In this phase the reliability of the time, energy and peak torque (PT) variables was verified. For the second phase the participant was submitted to two sessions: familiarization and test. In the test session, there was gas analysis and blood lactate concentration to determine the energy contribution and analysis of muscle activation to characterize muscle fatigue. Results: In relation to relative reliability only the time performance variables for one of the evaluators and the energy performance variable for both evaluators presented moderate intra-rater reliability. The other variables in the other moments presented good relative reliability. Regarding absolute reliability, the variables of time and energy performance presented a coefficient of variation (CV) greater than 15% and, for the variable PT, its value was up to 12.36% with a minimum detectable change (MMD) greater than 20% for all the variables. Regarding the contribution of the energy systems, there was an alpha anaerobic contribution of 50.5% and lactic acid of 43.7% and aerobic of 5.8%. For the voluntary activation analysis, a decrease of only 1% in its value was observed. Conclusion: It is concluded that IMFT presents moderate to good reliability for all performance variables analyzed both intra-rater and inter-rater, with high clinical applicability. Its metabolic demand demonstrated a predominance of anaerobic contribution with lactic and allematic equivalence, and it is not possible to identify any neuromuscular causes for the installation of muscular fatigue. (AU)

• FAPESP's process: 16/11785-7 - Reliability and physiological analysis of isometric muscular endurance test localized fatigue in isokinetic dynamometer
• Grantee: Larissa Rodrigues Souto
• Support Opportunities: Scholarships in Brazil - Master