Papers by Sidney Grosprêtre
Sports
Warm-up routines include various tasks focused on the peripheral contractile properties and nervo... more Warm-up routines include various tasks focused on the peripheral contractile properties and nervous motor command. This present study was aimed at investigating the acute effects of different warm-up routines, emphasizing either peripheral (post-activation performance enhancement, PAPE) or central (motor imagery, MI) contributions on sport-specific tasks. Eleven young female athletes took part in this cross-over, randomized, controlled trial. They underwent three experimental sessions composed of a standardized warm-up followed by 10 min of (1) rest (CONTROL), (2) maximal concentric leg press (PAPE), or (3) mental repetitions of sprint tasks (MI). Post-tests consisted of reaction time, arrowhead agility test, 20 m sprint, repeated sprint ability, and NASA-TLX fatigue questionnaire. PAPE and MI significantly enhanced the arrowhead agility test (p < 0.001 and p = 0.012, respectively) and repeated sprint ability (p = 0.002 and p = 0.035, respectively) compared to CONTROL, without an...
ABSTRACTTranscranial direct current stimulation (tDCS) is used to modulate the brain function in ... more ABSTRACTTranscranial direct current stimulation (tDCS) is used to modulate the brain function in targeted brain areas, and can acutely modulate motor control, such as postural control. While the acute effect of tDCS is well documented on patients, little is still known whether tDCS can alter the motor control of healthy populations with an already high level of motor skills. This study aimed to assess the acute effect of tDCS on postural control of trained athletes. Eighteen parkour practitioners, known for their good balance abilities, were tested on three occasions in the laboratory for each stimulation condition (2 mA ; 20 minutes) – primary motor cortex (M1), prefrontal cortex (dlPFC) and sham (placebo). Postural control was evaluated PRE and POST each stimulation by measuring Center of Pressure (CoP) displacements on a force platform during static conditions (bipedal and unipedal stance). Following M1 stimulation, significant decreases were observed in CoP area in unipedal (P=0...
Applied Sciences
Brain–computer interfaces (BCIs) have the potential to enable individuals to interact with device... more Brain–computer interfaces (BCIs) have the potential to enable individuals to interact with devices by detecting their intention from brain activity. A common approach to BCI is to decode movement intention from motor imagery (MI), the mental representation of an overt action. However, research-grade electroencephalogram (EEG) acquisition devices with a high number of sensors are typically necessary to achieve the spatial resolution required for reliable analysis. This entails high monetary and computational costs that make these approaches impractical for everyday use. This study investigates the trade-off between accuracy and complexity when decoding MI from fewer EEG sensors. Data were acquired from 15 healthy participants performing MI with a 64-channel research-grade EEG device. After performing a quality assessment by identifying visually evoked potentials, several decoding pipelines were trained on these data using different subsets of electrode locations. No significant diffe...
Movement & Sport Sciences - Science & Motricité
De manière très générale, malgré des débats (Marshall & Krüger, 1990), le sport peut être défini ... more De manière très générale, malgré des débats (Marshall & Krüger, 1990), le sport peut être défini selon les sept critères proposés par Allen Guttmann (1978 : 16) : l'aspect séculier, la rationalisation, la bureaucratisation, la quantification, l'égalité, la spécialisation et le record. Mais il peut également englober tous types d'activités physiques réalisées dans un but récréatif, hygiénique ou compétitif tout en se déroulant dans un cadre réglementaire minimal (Eichberg, 1998). De ce point de vue, le sport est aussi ancré dans notre quotidien et, de fait, au sein de la culture populaire. Pour le dire autrement, outre les pratiques physiques, il se donne aussi à voir à travers la matérialité (les objets, les vêtements, etc.) et sur les supports médiatiques (retransmission de matchs, jeux vidéo, etc.). Dans cette perspective, ce numéro spécial entend questionner les pratiques sportives et/ou ludiques productrices ou dérivant de la culture populaire. Cette notion est plurielle, composite et, pour Dominique Kalifa, il ne peut exister de définition qui fasse l'unanimité au sein de la communauté scientifique (Lynch, 2005 : 3) puisque la culture populaire est « complexe, protéiforme, investie d'enjeux politiques et idéologiques forts » (Kalifa, 2010 : 224). Plus encore, celle-ci est « plurielle, à la fois alternative et mainstream, commercial et militante, conformiste et subversive. C'est une boule à facettes où scintillent super-héros de bandes dessinées, personnages de cinéma, séries, jeux vidéo, looks et musiques qui font danser la planète » (Artus, 2018 : 14). Malgré tout, la culture populaire peut être envisagée de deux manières (Pasquier, 2005). D'une part, en héritage des travaux (essentiellement français) portant sur la théorie de la légitimité culturelle, la culture populaire peut être perçue comme la consommation des biens culturels par les classes populaires. Dans une autre optique, celle des cultural studies, la culture populaire est davantage appréhendée selon des approches localisées. Dès lors, loin d'être pensée dans un rapport hiérarchique, la culture populaire est ici un système de valeurs à part entière et un monde de sens (Becker, 2010). Dans tous les cas, les univers culturels sont hybrides et témoignent d'appropriations et de formes diverses de « braconnage » (De Certeau, 1990). De son côté, John Fiske s'ancre également dans cette logique puisqu'il met en avant une culture populaire correspondant à des productions ayant déjà fait l'objet d'une appropriation signifiante par le public (Fiske, 1989). Plus encore, dans le contexte actuel de « globalisation culturelle du sport » (Fournier & Raveneau, 2010), les outils des sportifs, les ustensiles personnels ou les bibelots du quotidien tels que les cartes postales, les jouets et, bien évidemment, les magazines, les bandes dessinées, les dessins animés, les séries TV, c'està-dire plus largement tous les objets fabriqués en séries ou non, peuvent être analysés, pour comprendre la dynamique de cette culture populaire sportive, au prisme de la culture matérielle. Selon Marie-Pierre Julien et Céline Rosselin, la culture matérielle regrouperait, dans une première acception, « l'ensemble des objets fabriqués par l'homme considéré sous l'angle social et culturel » (Julien & Rosselin, 2005 : 3). Mais celle-ci englobe aussi les liens entre l'objet, le geste et l'acteur dans la mesure où une deuxième acception de ce concept « engagerait […] à considérer les objets matériels comme corrélats de l'action individuelle et collective » (Julien & Rosselin, 2005 : 6). Aussi, ce qui fait culture matérielle correspond aux objets fabriqués par l'homme (artefacts) propres à une société et qui sont les produits d'une culture. La relation technique entre les objets et les acteurs témoigne donc de cette culture matérielle qui inclut l'usage, la consommation, la création, le commerce, ainsi que les comportements, les normes et les rituels mis en jeu par ces objets. Ces objets du quotidien, ce « petit patrimoine » comme l'évoque Laurent Sébastien Fournier (2008), ont peu suscité d'intérêt des scientifiques. Pourtant, l'histoire s'écrit aussi à travers eux. Le livre Une histoire du monde en 100 objets de Neil Mac Gregor publié en 2010 en partenariat avec le British Museum et le très récent Une histoire du monde par les objets (du 18 e à nos jours) (Singaravélou & Veynare, 2020) prouvent, s'il en est, l'intérêt et le renouveau pour les études sur les objets qu'ils soient artistiques, décoratifs, publicitaires, utilitaires ou rituels. En sciences du sport, les recherches portent très souvent sur l'analyse des pratiques dites populaires, comme le football (Correia, 2018 : Faure, 1999), les spectacles (Faure, 1990) ou le supportérisme (Lestrelin, 2022). D'autres travaux mettent en avant les processus d'intégration du sport au sein de la jeunesse (Mignon, 1999) ou du mouvement ouvrier (Kssis, 2002), mais peu d'études tentent d'articuler la culture populaire et la culture matérielle. En pionnier, Jacques Defrance a montré, dès 1985, comment les mutations techniques en saut à la perche provoquent des réaménagements des pratiques sportives (Defrance, 1985). Bien évidemment, l'ouvrage novateur en la matière est celui de Georges Vigarello (1988) qui retrace l'évolution simultanée des techniques et de certains objets sportifs au cours
Movement & Sport Sciences - Science & Motricité, 2022
Parkour consists of overcoming obstacles mostly in an urban landscape. Little is known regarding ... more Parkour consists of overcoming obstacles mostly in an urban landscape. Little is known regarding usual training habits and injury risks of traceurs, i.e., parkour practitioners. In this study, a 20-min survey have been fulfilled by a population of traceurs regarding training load, habits (type of warm up, physical conditioning, stretching), type of footwear, and number and type of ankle- and knee-injuries during their career. A total of 180 responses were analyzed (24.4 ± 5.9 years old, 21.7% female, 6.0 ± 3.9 years of experience). Participants reported to train 1 to 7 times per week for a mean duration of 2.2 h. 76% practiced stretching exercises. 75.6% practiced physical conditioning in addition to their parkour training (weightlifting, functional exercises). Injury rate was 1.7 per 1000 h of training, mostly ankle sprains and knee contusions. Number of injury and training load were positively correlated. The lack of physical conditioning was also a factor of injury. Knee injuries...
Perceptual and Motor Skills, 2020
Domain-specific knowledge guides our attention and thus influences our perception. Prior change-b... more Domain-specific knowledge guides our attention and thus influences our perception. Prior change-blindness research has shown that expert athletes can spot meaningful scene changes more quickly than novices, but less is known of whether this expertise is modulated differentially between open and closed sporting activities. We presented 81 individuals (20 gymnasts, 19 rock climbers, 22 parkour practitioners, and 20 control participants) with alternating sequences of images that corresponded to the habitual training landscapes of each group (gymnasiums, rock cliffs, and urban environments, respectively). We included contextual and non-contextual scenic changes to evaluate whether athletes were generally aware of their environments, or whether their observation strategies only targeted sport-related environmental elements. Among these three athletic endeavors, we found that gymnasts were faster at detecting changes in their environment, irrespective of whether or not these changes were ...
The Journal of Physiology, 2019
Movement & Sport Sciences - Science & Motricité, 2017
The present study aimed at investigating different variables that can be manipulated prior to and... more The present study aimed at investigating different variables that can be manipulated prior to and during take-off, to execute a specific standing long jump (SLJ) distance, according to jump expertise in parkour practitioners (= traceurs). Fourteen healthy young traceurs were included and separated into two groups: beginners (BEG) and experts (EXP). Firstly, classical vertical jump battery was used to characterize participants arm use and leg efficiency. Secondly, standing long jump (SLJ) performances were analyzed at four distances: 70, 80, 90, and 100% of each participant’s maximal SLJ distance. The force-time curves of the ground reaction forces (GRF) and the center of pressure (CoP) trajectory were measured with a force platform during the jump impulses. Take-off speed, angle and jump trajectory were estimated. For all of the participants, take-off speed and angle, power output, and vertical GRF during jump preparation (counter movement) varied with distance. The EXP group exhibi...
Journal of Science in Sport and Exercise
European Journal of Applied Physiology
To counteract the detrimental health effect of sitting all day long, it has been suggested to reg... more To counteract the detrimental health effect of sitting all day long, it has been suggested to regularly break sitting time by standing. However, while the difference in energy expenditure, neuromuscular and/or cardiovascular demand of various postures from lying, sitting, and standing is well documented, little is known regarding the dynamic changes occurring during the sit-to-stand transition itself. The aim of the present study was then to describe the cardiometabolic and neuromuscular responses from sitting to standing and specifically during the time-course of this transition. Twelve healthy young participants were asked to perform standardized raises from sitting posture, while cardiometabolic (cardiorespiratory and hemodynamic variables) and neuromuscular (calf muscles' myoelectrical activity, spinal and supraspinal excitabilities) parameters were monitored. As a result, while there was a rapid adaptation for all the systems after rising, the neuromuscular system displayed the faster adaptation (~ 10 s), then hemodynamic (~ 10 to 20 s) and finally the metabolic variables (~ 30 to 40 s). Oxygen uptake, energy expenditure, ventilation, and heart rate were significantly higher and stroke volume significantly lower during standing period compared to sitting one. In calf muscles, spinal excitability (H-reflexes), was lowered by the sit-to-stand condition, while supraspinal drive (V-wave) was similar, indicating different cortico-spinal balance from sitting to standing. Although very heterogenous among participants in terms of magnitude, the present results showed a rapid adaptation for all the systems after rising and the health benefit, notably in terms of energy expenditure, appears rather modest, even if non negligeable.
Additional file 1. SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protoc... more Additional file 1. SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents.
European Journal of Applied Physiology, 2021
Purpose This study investigated the effects of force and electromyographic (EMG) feedbacks on for... more Purpose This study investigated the effects of force and electromyographic (EMG) feedbacks on forearm muscle activations and handgrip maximal isometric voluntary contraction (MIVC). Methods Sixteen males performed a set of MIVC in four different feedback conditions: (1) NO-FB: no feedback is given to the participant; (2) FORCE-FB: participants received a visual feedback of the produced force; (3) AGO-FB: participants received a visual feedback of the EMG activity of two agonist grip muscles; (4) ANTAGO-FB: participants received a visual feedback of the EMG activity of two hand extensors muscles. Each feedback was displayed by monitoring the signal of either force or electrical activity of the corresponding muscles. Results Compared to NO-FB, FORCE-FB was associated with a higher MIVC force (+ 11%, P < 0.05), a higher EMG activity of agonist and antagonist muscles (+ 8.7% and + 9.2%, respectively, P < 0.05) and a better MIVC/EMG ratio with the agonist muscles (P < 0.05). AGO-FB was associated with a higher EMG activity of agonist muscles (P < 0.05) and ANTAGO-FB was associated with a higher EMG activity of antagonist muscles (P < 0.05). MIVC force was higher in the agonist feedback condition than in the antagonist feedback condition (+ 5.9%, P < 0.05). Conclusion Our results showed that the MIVC force can be influenced by different visuals feedback, such as force or EMG feedbacks. Moreover, these results suggested that the type of feedback employed could modify the EMG-to-force relationships. Finally, EMG biofeedback could represent an interesting tool to optimize motor strategies. But in the purpose of performing the highest strength independently of the strategy, the force feedback should be recommended.
Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology, 2021
Two main types of endurance runners have been identified: aerial runners (AER), who have a larger... more Two main types of endurance runners have been identified: aerial runners (AER), who have a larger flight time, and terrestrial runners (TER), who have a longer ground contact time. The purpose of this study was to assess the neuromuscular characteristics of plantar flexors between AER and TER runners. Twenty-four well-trained runners participated in the experiment. They were classified either in a TER or AER group according to the Volodalen® scale. Plantar flexors' maximal rate of force development (RFD) and maximal voluntary contraction force (MVC) were assessed. Percutaneous electrical stimulation was delivered to the posterior tibial nerve to evoke maximal M-waves and H-reflexes of the triceps surae muscles. These responses, as well as voluntary activation, muscle potentiation, and V-waves, were recorded by superimposing stimulations to MVCs. RFD was significantly higher in AER than in TER, while MVC remained unchanged. This was accompanied by higher myoelectrical activity re...
Frontiers in Physiology, 2021
Motor imagery (MI) for health and performance strategies has gained interest in recent decades. N... more Motor imagery (MI) for health and performance strategies has gained interest in recent decades. Nevertheless, there are still no studies that have comprehensively investigated the physiological responses during MI, and no one questions the influence of low-level contraction on these responses. Thus, the aim of the present study was to investigate the neuromuscular, autonomic nervous system (ANS), and cardiometabolic changes associated with an acute bout of MI practice in sitting and standing condition. Twelve young healthy males (26.3 ± 4.4 years) participated in two experimental sessions (control vs. MI) consisting of two postural conditions (sitting vs. standing). ANS, hemodynamic and respiratory parameters, body sway parameters, and electromyography activity were continuously recorded, while neuromuscular parameters were recorded on the right triceps surae muscles before and after performing the postural conditions. While MI showed no effect on ANS, the standing posture increased...
BMC Public Health, 2021
Background Sedentary lifestyles plague today’s society in terms of physical, psychosocial and cog... more Background Sedentary lifestyles plague today’s society in terms of physical, psychosocial and cognitive health. Students are particularly at risk because they spend most of their daily time sitting and inactive. The current pedagogical model must be rethought in order to promote students’ health, well-being and therefore their success. The objective of this project was to equip one classroom of the sport science department at a university with various active workstations (standing desks, Swiss balls, cycling desks, pedal- or stepper-board) and to evaluate the feasibility and influence of these types of active workstations on the cognitive and psychological factors of the students, and to collect the feedback of lecturers during this experience. Methods Participation in the study was voluntary and students had the opportunity to choose or not to use an active workstation during lectures. A total of 663 students and 14 lecturers completed a survey to evaluate subjective feelings about...
Applied Psychophysiology and Biofeedback, 2021
This study aimed to investigate the relationship between neural efficiency and the ability of an ... more This study aimed to investigate the relationship between neural efficiency and the ability of an athlete to produce accurate efforts in different perceived intensity zones during a racing scenario. The α/β ratio was used to quantify the neural efficiency during cycling, as it traduced the degree of participants information processing activity with lower cortical activity possible. Twelve trained competitive male cyclists delimited their perceived intensity zones 2 to 6 on a scale to assess the rating of exercise intensity. Then, they performed a 30 min racing scenario during which they had to produce different perceived intensities. The ability of athletes to produce perceived effort with accuracy and their neural efficiency was quantified during the racing scenario. The increase in the neural efficiency with the increase in the effort intensity could partly explain the improvement in athletes' ability to produce accurately perceived efforts from intensity zones 3 to 6. Moreover, the neural efficiency during the racing scenario was significantly correlated to the ability to produce perceived effort with accuracy at submaximal intensities.
Applied Ergonomics, 2021
This study aimed 1) to assess the psychophysiological responses throughout a rescue intervention ... more This study aimed 1) to assess the psychophysiological responses throughout a rescue intervention performed during the day and at night and 2) to determine if a vibrating alarm influences these psychophysiological responses at night. Sixteen male firefighters completed a simulated intervention under three different conditions: 1) during the day with a sound alarm signal (DaySA), 2) during the night with a sound alarm signal (NightSA), 3) during the night with a vibrating alarm signal (NightVA). Cardiovascular and psychological stress were recorded throughout the interventions. During the alarm signal, HR reactivity was greater in NightSA than in DaySA (p < 0.01). Parasympathetic reactivation and self-confidence were significantly lower in NightSA than in DaySA (p < 0.05). HR reactivity was decreased in NightVA in comparison to NightSA (p < 0.05). Overall, the rescue intervention had a greater impact on the psychophysiological variables during the night than during the day, and the type of alarm had a minor effect.
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Papers by Sidney Grosprêtre