Number of Trials Necessary to Apply Analysis within the Framework of the Uncontrolled Manifold Hypothesis at Different Levels of Hierarchical Synergy Control

The uncontrolled manifold hypothesis is a method used to quantify motor synergies, defined as a specific central nervous system organization that maintains the task-specific stability of motor actions. The UCM allows for inter-trial variance analysis between consecutive trials. However, despite the large body of literature within this framework, there is no report on the number of movement repetitions required for reliable results. Based on the hypothetical hierarchical control of motor synergies, this study aims to determine the minimum number of trials necessary to achieve a good to excellent level of reliability. Thirteen young, healthy participants performed fifteen bilateral isometric contractions of elbow flexion when visual feedback was provided. The force and electromyography data were recorded to investigate synergies at different levels of hierarchical control. The intraclass correlation coefficient was used to determine the reliability of the variance indices. Based on the obtained results, at least twelve trials are required to analyze the intertrial variance in both force and muscle synergies within the UCM framework.

Pawłowski, M., Furmanek, M. P., Sobota, G., Marszałek, W., Słomka, K. J., Bacik, B., Juras, G. (2021). Number of Trials Necessary to Apply Analysis within the Framework of the Uncontrolled Manifold Hypothesis at Different Levels of Hierarchical Synergy Control. Journal of Human Kinetics, 76, 131-143. https://doi.org/10.2478/hukin-2021-0005

Pawłowski, M., Furmanek, M. P., Sobota, G., Marszałek, W., Słomka, K. J., Bacik, B., and Juras, G. (2021). Number of Trials Necessary to Apply Analysis within the Framework of the Uncontrolled Manifold Hypothesis at Different Levels of Hierarchical Synergy Control. Journal of Human Kinetics, 76, pp.131-143. https://doi.org/10.2478/hukin-2021-0005

Pawłowski, Michał et al. “Number of Trials Necessary to Apply Analysis within the Framework of the Uncontrolled Manifold Hypothesis at Different Levels of Hierarchical Synergy Control.” Journal of Human Kinetics, vol. 76, 2021, pp. 131-143. doi:10.2478/hukin-2021-0005.

Pawłowski M, Furmanek MP, Sobota G, Marszałek W, Słomka KJ, Bacik B et al. Number of Trials Necessary to Apply Analysis within the Framework of the Uncontrolled Manifold Hypothesis at Different Levels of Hierarchical Synergy Control. Journal of Human Kinetics. 2021;76:131-143. https://doi.org/10.2478/hukin-2021-0005