Submaximal fast force generation control assessment: Electromyographic analysis and comparisons across populations

• Grant number: 24/08749-5
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2024
• End date: October 31, 2027
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Paulo Barbosa de Freitas Júnior
• Grantee: Paulo Barbosa de Freitas Júnior
• Host Institution: Pró-Reitoria de Pós-Graduação e Pesquisa. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil

Abstract

Rapid force generation is essential for daily activities and postural stability. The rate of force development (RFD) is a common measure of this capacity, but it may not accurately reflect submaximal force production in everyday tasks. The RFD scaling factor (SF-RFD) emerges as a promising alternative, demonstrating reliability and sensitivity across populations and contexts. This in-depth study aims to unravel the physiological and motor control mechanisms underlying submaximal rapid force generation, utilizing electromyography (EMG) to analyze agonist and antagonist muscles during specific tasks. The scaling factor of the rate of agonist muscle activation (SF-RAMA) and the coactivation index (ICOA) of agonist and antagonist muscles will be calculated during force pulse production tasks involving elbow extension and ankle dorsiflexion.The aims of the study are: 1) to optimize EMG signal processing methods for obtaining the most reliable SF-RAMA and ICOA measures, 2) to determine the minimum number of force pulses required for reliable results, 3) to compare SF-RFD, SF-RAMA, and ICOA between young men and women, 4) to compare SF-RFD, SF-RAMA, and ICOA between young and older adults, 5) to investigate the associations between SF-RFD and SF-RAMA and between SF-RFD and ICOA. This project will establish robust EMG analysis methods for rapid force generation, identify differences in SF-RFD, SF-RAMA, and ICOA across populations, and elucidate the relationships between EMG variables and rapid force generation capacity. The findings will provide valuable insights into the underlying mechanisms of rapid force generation and inform the development of more effective interventions to enhance motor performance and functionality in diverse populations. The assessments will be conducted in the laboratory. Participants (young adults in the first two studies and elderly individuals in the third) will perform two tests in each study: one involving maximal force production and the other involving the generation of force pulses at different magnitudes. The force generated and the electromyographic activity of the muscles responsible for force generation (elbow extensors and ankle dorsiflexors) will be recorded, processed, and analyzed to obtain the outcomes of interest. (AU)