Differences between Mental and Physical Preparation of Muscular Contraction: A Pilot Study Yosra Saidane 1 , Sofia Ben Jebara 1 Tarak Driss 2 and Giovanni de Marco 2 1 University of Carthage, Higher School of Communications of Tunis, LR11TIC01, COSIM Lab, Route de Raoued KM 3.5, Cite El Ghazala Ariana 2083, Tunisia 2 Universit´ e Paris Nanterre, Centre de Recherches sur le Sport et le Mouvement, 92000 Nanterre, France Keywords: Mental Preparation, Physical Preparation, EMG Signal, Normalized Mutual Information, Mean Normalized Preparation Power. Abstract: This paper studies some differences between mental and physical preparation of muscular contraction from a signal processing point of view. Mental preparation is a cognitive process prior to performance while physical preparation is a bodily movement produced by skeletal muscles. Two features are selected. The first indicator, called Mean Normalized Preparation Power (MNPP), represents the amount of muscular activity produced during preparation. The second feature, called Normalized Mutual Information (NMI), studies the functional connectivity between a pair of agonist/antagonist muscles entering in action. Results showed that connectivity is more important in Mental Preparation Activity (MPA) than in Physical Preparation Activity (PPA) while muscles power is more important in PPA than in MPA. When classifying the preparation according to muscular activity importance (low and large preparation), previous conclusions are valid for large preparation. In case of small preparation, there is no differences between MPA and PPA in term of MNPP while MPA has higher NMI. Finally, the study of the correlation between MNPP and NMI showed a moderate dependence with the agonist muscle and an independence with the antagonist muscle. 1 INTRODUCTION Finding the best preparation of physical activity is al- ways a daily issue especially during the instants pre- ceding the activity beginning. This activity, called motor preparation (Henry and Rogers, 1960), is use- ful in many fields like sports and rehabilitation. In sports, some studies showed that motor preparation is effective for performance enhancement in basket- ball free throw shooting (Lonsdale and Tam, 2008), golf putting (Bell et al., 2010), water polo penalty (Marlow et al., 1998), rugby goal kicking (Jackson and Baker, 2001) and volleyball serving(Lidor and Mayan, 2005). In rehabilitation, one study demon- strated that motor preparation promote the relearning of motor strategies post-stroke on patients with stroke (Malouin et al., 2009). It was also shown beneficial effects in patients with Parkinson’s disease especially for reducing bradykinesia (Tamir et al., 2007). Motor preparation is classified into two types: mental and physical preparation. Physical Prepara- tion Activity (PPA) is defined as any bodily move- ment produced by skeletal muscles that results in en- ergy expenditure (Caspersen et al., 1985) while Men- tal Preparation Activity (MPA) is the cognitive re- hearsal of a task prior to performance (Driskell et al., 1994). In this work, we aim studying the differences be- tween these two ways of preparation by considering a handgrip exercise. To study the differences between PPA and MPA, the mean power of preparation activ- ity that appears in EMG signals (Tabar et al., 2017) and the functional connectivity between the two con- sidered muscles during the preparation stage are ad- dressed. The functional connectivity is described through the Normalized Mutual Information (NMI) feature (Arjunan and Kumar, 2015; Kawczy´ nski et al., 2015; Madeleine et al., 2011; Saidane and BenJebara, 2017; Johansen et al., 2013). In a previous work, we showed that the functional connectivity between ag- onist and antagonist muscles increases during move- ment’s initiation and then decreases during effective contraction (Saidane and BenJebara, 2017). It means that agonist/antagonist muscles put their effort to- gether to initiate the movement. We also showed that when subjects prepare their movement, the inter- muscular dependence in greater than the one without preparation at movement’s initiation. When dealing Saidane, Y., Ben Jebara, S., Driss, T. and de Marco, G. Differences between Mental and Physical Preparation of Muscular Contraction: A Pilot Study. DOI: 10.5220/0007256301010108 In Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2019), pages 101-108 ISBN: 978-989-758-353-7 Copyright c  2019 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved 101