Control of muscle force development in arm extensors during isometric tension

The aim of this study is to determine the patterns of force development regulation in arm extensors during isometric tension using the standardized Bench Press test. An evaluation of control for each subject has been made based on the level of force achieved (30%, 50%, 70% and 90%), the rate of force development (RFD), the speed of inclusion of motor units (k), the time necessary to achieve the given level (t) and the differences recorded in the first (initial) and repeated measurements. The experiment was carried out on a sample of 130 respondents. Descriptive and comparative statistics was used along with nonlinear mathematical modeling methods for the analysis of experimental results and for establishing the patterns of control. The results of the analysis indicate that there are statistically significant differences (p lt 0.01) between the mean values of generated force, generating time, the rate of force development, the speed of inclusion of motor units in a given unit of time and the mean values of the same parameters in repeated measurement at all levels except at the levels of force F-70% (p = 0.02), and F-90% (p = 0.52). The models of force control have a high predictive value, ranging from 90% to 99.88% and a small prediction error, which is in the range from 0.12% to 10%. All analyses indicate high reliability of the results of this research and are therefore recommended for use in research and educational practice.