Simple Movements Research Articles

The possibility to apply the Frenet trihedron and formulas for the complex movement of a point on a plane with the predefined plane displacement

Material particles interact with the working moving surfaces of machines in various technological processes. Mechanics considers a technique to describe the movement of a point and decompose the speed and acceleration into single unit vectors of the accompanying trajectory trihedron for simple movement. The shape of the spatial curve uniquely sets the movement of the accompanying Frenet trihedral as a solid body. This paper has considered the relative movement of a material particle in the static plane of the accompanying Frenet trihedron, which moves along a flat curve with variable curvature. Frenet formulas were used to build a system of differential equations of relative particle movement. In contrast to the conventional approach, the chosen independent variable was not the time but the length of the arc of the guide curve along which the trihedron moves. The system of equations has been built in the projections onto the unit vectors of the moving trihedron; it has been solved by numerical methods. The use of the accompanying curve trihedron as a moving coordinate system makes it possible to solve the problems of the complex movement of a point. The shape of the curve guide assigned by parametric equations in its length function determines the portable movement of the trihedron and makes it possible to use Frenet formulas to describe the relative movement of a point in the trihedron system. This approach enables setting the portable movement of the trihedron osculating plane along a curve with variable curvature, thereby revealing additional possibilities for solving problems on a complex movement of a point at which rotational motion around a fixed axis is a partial case. The proposed approach has been considered using an example of the relative movement of cargo in the body of a truck moving along the road with a curvilinear axis of variable curvature. The charts of the relative trajectory of cargo slip and the relative speed for the predefined speed of the truck have been constructed

Biotemplated Fabrication of a Multifunctional Superwettable Shape Memory Film for Wearable Sensing Electronics and Smart Liquid Droplet Manipulation.

Wearable superwettable surfaces with dynamic tunable wettability and self-healability are promising for advanced wearable electronics, whereas have been rarely reported. Herein, a flexible superhydrophobic shape memory film (SSMF) with switchable surface wettability and high strain sensitivity has been conveniently fabricated. The surface topography of the SSMF can be finely adjusted by a reversible stretching (bending)/recovery way, which makes it feasible to control the surface-switchable adhesive superhydrophobicity by simple body movements, demonstrating great advantages in selective droplet manipulation and smart control of droplet movement. Moreover, benefitting from the hierarchical micro/nanostructures and outstanding sensing performance, the flexible SSMFs with good adaptivity and durability can serve as smart wearable sensors attached to human skin to achieve full-range and real-time detection of human motions and intelligent control of Internet of Things. More interestingly, the unique dynamic dewetting property enables the sensors to work in a humid environment or rainy days. Overall, this work successfully integrates dynamic tunable superwettability into design of intelligent wearable electronics with multifunctions. The obtained SSMF-based wearable surface with dynamic dewetting properties reveals great potential in versatile application fields such as liquid-repellent electronics, wearable droplet manipulators, and all-weather intelligent actuators.

Handedness effects on motor imagery during kinesthetic and visual-motor conditions

Recent studies show that during a simple movement imagery task, the power of sensorimotor rhythms differs according to handedness. However, the effects of motor imagery perspectives on these differences have not been investigated yet. Our study aimed to check how handedness impacts the activity of alpha (8–13 Hz) and beta (15–30 Hz) oscillations during creating a kinesthetic (KMI) or visual-motor (VMI) representation of movement. Forty subjects (20 right-handed and 20 left-handed) who participated in the experiment were tasked with imagining sequential finger movement from a visual or kinesthetic perspective. Both the electroencephalographic (EEG) activity and behavioral correctness of the imagery task performance were measured. After the registration, we used independent component analysis (ICA) on EEG data to localize visual- and motor-related EEG sources of activity shared by both motor imagery conditions. Significant differences were obtained in the visual cortex (the occipital ICs cluster) and the right motor-related area (right parietal ICs cluster). In comparison to right-handers who, regardless of the task, demonstrated the same pattern in the visual area, left-handers obtained higher power in the alpha waves in the VMI task and better performance in this condition. On the other hand, only the right-handed showed different patterns in the alpha waves in the right motor cortex during the KMI condition. The results indicate that left-handers imagine movement differently than right-handers, focusing on visual experience. This provides new empirical evidence on the influence of movement preferences on imagery processes and has possible future implications for research in the area of neurorehabilitation and motor imagery-based brain–computer interfaces (MI-BCIs).

Metaheuristic algorithm for anomaly detection in Internet of Things leveraging on a neural-driven multiagent system

Detecting unusual data, activities and user behaviors is an extremely important task to acquire relevant security information that allow identifying faults, intrusions and system malfunctions. In Internet of Things (IoT), conventional anomaly detection approaches are not particularly appropriated due to the limited computing resources and the high dynamism of the entities involved. This paper proposes an activity footprints based method to detect anomalies in IoT by exploiting a multiagent algorithm. Devices and services are represented using dense vectors obtained through IoT2Vec, a word embedding technique able to capture the semantic context and represent them with high-dimensional vectors. The method allows mapping sequences of specific device activities – digital footprints – with real-valued vectors. The vectors are assigned to mobile agents that act following each one a modified bio-inspired model. This model enables an intelligent global behavior to emerge on the basis of simple local movement rules observed by all agents onto a virtual 2D space. A tailored similarity rule, based on the Pearson’s correlation, drives each agent for a selective application of the movement rules, so enabling an automatic closer positioning of similar agents. The intelligent positioning (clustering), driven by the assigned vectors, allows identifying isolated agents, representing devices with unusual activities to be monitored, since they can be associated to potential intruders or malicious users. Experimental results confirm the validity of the metaheuristic algorithm.

EFEKTIVITAS SENAM OTAK TERHADAP KONSENTRASI BELAJAR PADA SISWA KELAS V DI YAYASAN PENDIDIKAN ISLAM ISTIQOMAH MEDAN TAHUN 2020

Brain exercise is a series of simple movements that help optimize the function of all kinds of centers in the human brain. The brain exercise method focuses on the use of movemment activities to draw out all one’s potential so that it is expected to facilitate blood flow and stretch nerves due to fatigue and stress of learning. The purpose of this study was to determine the effectiveness of brain exercise on learning concentration in grade V students at the Istiqomah Medan Islamic Education Foundation. This study used a quasi experimental research design with one group pretest-posttest designs. Analysis of data using the wilcoxon test. Population of 42 students, the sampling technique used a total population of 42 students. The results of data processing using the wilcoxon test obtained a p value of 0,000 < 0,05 then Ho is rejected and Ha is accepted. The conclusion is that there is the effectiveness of brain exercise on learning concentration in grade V students at the Istiqomah Medan Islamic Education Foundation. The suggestion from the reseacher is to recommend the teacher to intruct students to do brain exercises to increase learning concentration.

Dexterous manual movement facilitates information processing in the primary somatosensory cortex: A magnetoencephalographic study.

The interaction between the somatosensory and motor systems is important for control of movement in humans. Cortical activity related to somatosensory response and sensory perception is modulated by the influence of movement executing mechanisms. This phenomenon has been observed as inhibition in the short‐latency components of somatosensory evoked potentials and magnetic fields (SEPs/SEFs). Although finger is the most dexterous among all the body parts, the sensorimotor integration underlying this dexterity has not yet been elucidated. The purpose of this study was to examine the sensorimotor integration mechanisms in the primary somatosensory cortex (SI) during simple and complicated finger movement. The participant performed tasks that involved picking up a wooden block (PM task) and picking up and turning the wooden block 180° (PTM task) using the right‐hand fingers. During these tasks, the SEFs following right median nerve stimulation were recorded using magnetoencephalography. The amplitude of the M20 and M30 components showed a significant reduction during both manual tasks compared to the stationary task, whereas the M38 component showed a significant enhancement in amplitude. Furthermore, the SEFs recorded during continuous rotation of the block (rotation task) revealed a characteristic pattern of SI activity that was first suppressed and then facilitated. Since this facilitation is noticeable during complicated movement of the fingers, this phenomenon is thought to underlie a neural mechanism related to finger dexterity.

REM sleep behaviour disorder in Parkinson's disease (Review).

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia defined by simple or complex abnormal movements occurring in REM state, instead of the physiological muscular atonia. RBD may be idiopathic, or secondary as in the case of Parkinson's disease (PD). Several studies have confirmed that idiopathic RBD may precede with several years the onset of the specific motor characteristics of PD. The high prevalence of RBD in PD (19-70%) may be explained by several common pathophysiological pathways, mainly related to the dopaminergic cell loss. RBD is also associated with several comorbidities, including cognitive impairment, hallucinations, dysautonomia, or daytime sleepiness. The gold standard investigation for the diagnosis and assessment of RBD is video polysomnography, but in clinical practice, the use of clinical scales and questionnaires is reasonable for the screening of this complex parasomnia. Management options include ensuring a safe environment for the patient and pharmacological treatment, incuding clonazepam, melatonin or certain antiparkinsonian drugs.

The Effects of Animistic Thinking, Animistic Cues, and Superstitions on Brand Responses on Social Media

Although marketers have been using various message tactics to breathe life into their brands, the concepts of animism and animistic cues, particularly in social media marketing, have received little theoretical and empirical attention. Therefore, we conducted two studies to uncover what drives animistic thinking on social media, how animism is linked to anthropomorphism, how animism can benefit brands online, and what the boundary conditions for this phenomenon are. The findings demonstrate that animistic (vs. non-animistic) cues elicit animistic thinking, which leads to more favorable brand evaluations. This effect is moderated by superstitious beliefs. The results provide new knowledge for both marketing researchers and practitioners, revealing that it is easier to activate animism than anthropomorphism on social media and that such activation can be done via easily devisable cues (such as simple movement), particularly when addressing highly superstitious consumers.

“I Like the Way You Move”: Validating the Use of Point-Light Display Animations in Virtual Reality as a Methodology for Manipulating Levels of Sexualization in the Study of Sexual Objectification

Sexual objectification of others has seen a growing research interest in recent years. While promising, the field lacks standardized stimuli, resulting in a confusion between sexualization and sexual objectification, which limits the interpretability of published results. In this study, we propose to use point-light display (PLD) as a novel methodology for manipulating sexualization levels as a first step toward isolating movement from other visual cues (e.g., clothing or physical appearance) for studying effects of sexual objectification of others. To do so, we first developed 8 virtual reality animations varying on 3 dimensions: 1) nature of movement (dance vs. walk), 2) level of sexualization (low vs. high), and 3) animation speed (slow and fast). Then, we validated these stimuli with perception ratings from 211 participants via an online survey. Using mixed linear regression models, we found evidence that our manipulation was successful: while participants took longer, were less accurate, and less confident in their response when confronted with a dancing, sexualized PLD, they also rated it as significantly more sexualized. This latter effect was stronger for participants perceiving a woman dancing compared to participants who perceived other genders. Overall, participants who reported more frequent sexual objectification behaviors also perceived the animations as more sexualized. Taken together, these results suggest that sexual suggestiveness can be manipulated by rather simple movement cues, thus validating the use of PLD as a stepping stone to systematically study processes of sexual objectification. From there, it is now possible to manipulate other variables more precisely during immersions in virtual reality, whether by adding a skin to the animated skeleton, by situating the PLD into different context, by varying the amplitude and the nature of the movements, or by modifying the context of the virtual environment.

Development of Computer Based Diagnostic Assessment Completed with Simple Harmonic Movement Material Remedial Program

Research and development of computer-based assessment is carried out to overcome the shortcomings of conventional paper-based assessment. Development is carried out by focusing on the use of isomorphic questions and improvement programs. This computer-based assessment was developed with two levels of questions. At each level there are isomorphic questions that are used as a reference in providing feedback to students about their concepts understanding. At each level there is also video material that can be used as a source of student learning before students utilize the remedial program. This computer-based assessment has been tested on 31 third-year undergraduate students in Physics Education, Universitas Negeri Malang. The results of media and material validation and the results of limited trials indicate that the computer-based assessment produced is feasible to be applied in learning.

ВИКОРИСТАННЯ ФІЗКУЛЬТХВИЛИНОК ДЛЯ РОЗВИТКУ ЛЕКСИЧНОЇ КОМПЕТЕНТНОСТІ УЧНІВ ПЕРШОГО КЛАСУ НА УРОКАХ АНГЛІЙСЬКОЇ МОВИ

The work undertaken is aimed at composing rhymes and designing movements for physical action time, implementation of which will contribute to primary school learners’ mastering lexical competence at English lessons according to the approved curriculum for the first year of learning. The work is focused on analyzing scientific and methodological sources, reviewing the content of the curriculum of “English” subject for first-graders, composing rhymes as well as choosing simple and understandable movements accompanying them drawing from the content of the topics selected from the curriculum. To achieve the objective formulated, the analysis of scientific and methodological literature alongside with the content analysis of the curriculum of “The English Language” subject for the first-grade students was conducted. The main methods applied to teaching English are enumerated, among which are «total physical response», association method, gaming method «move-about games», Gromiko’s sports method. The advantages of using specially composed rhymes and designed movements implemented in physical action time during English lessons are rationalized on the basis of theoretical arguments with a view to simultaneously solving educational and health-improving goals, which imply getting learners interested in a new topic and consolidating the lexical material previously acquired along with shifting learners’ attention to physical movement, relieving muscular tension, improving emotional display of teaching-learning process respectively. The range of the topics taken from the subject curriculum is set, which are prescribed for acquiring during the first year of children’s going to primary school; the amount of the lexical material which is necessary for learners to acquire is determined. The rhymes and movements selected and proposed for use are composed with due regard for the content of the curriculum of «English» subject for first-grade learners, physiological needs of primary-school children’s organism as well as specificities of children’s certain mental processes. Implementation of the designed movements with the rhymes accompanying them is considered to be one of the methods of teaching English in motion. The practical relevance of the research results lies in enhancing effectiveness of first-graders’ acquiring lexical units with their age, physical and psychological features taken into account. Key words: physical action time, lexical competence, learners, teaching methods, health preservation, English.

Motion based message carrier for disabled people

We come across many disabled people in NGO’s and hospitals. These people find difficult to convey message as they cannot make full body movement like normal people. Looking at such condition we tried to make a system which can be used to convey messages on behalf of such people. This system give different messages by simple movement of hand of the person. The device is placed on person’s hand so the he can tilt it in particular direction. By tilting the device in different direction in a specified range of angle different messages are displayed. Here an accelerometer is used to measure the tilt. The data from the accelerometer is then passed to the microcontroller. The microcontroller takes the information, process the data and shows the particular message depending on the tilt by the person. The microcontroller send data to a LCD screen and desired message is displayed. On the receiver side along with LCD screen a buzzer is also present and in gets on as soon as it receives signal from the accelerometer. On person’s hand the device consists of an RF transmitter which is used to transfer the data signal in encoded form. On the receiving end the RF receiver gets the data from the transmitter and then decodes it and which is then passed to the microcontroller for reading the data, processing the data and responding to it.

Design of Laboratory Dynamic Balancing Device and Investigation of Vibrations of Rotating Bodies

The rotor part to be balanced is mounted on the balancing device using a suitably designed fixture. When the rotor is rotated around its own axis, static and dynamic unbalance in the rotor, static and dynamic bending, which are simple harmonic movements in nature, cause oscillating motion. This harmonic motion of the static and dynamic elasticities is detected by the respective sensors and converts the mechanical input of the harmonic motion proportionally to the electrical voltage output. These readings are used to calculate the current static and dynamic unbalance in the rotor using the calibration constants. In this study, we designed a new balancing machine by using Arduino and MATLAB program and gave analysis results.

IntelliRehabDS (IRDS)—A Dataset of Physical Rehabilitation Movements

In this article, we present a dataset that comprises different physical rehabilitation movements. The dataset was captured as part of a research project intended to provide automatic feedback on the execution of rehabilitation exercises, even in the absence of a physiotherapist. A Kinect motion sensor camera was used to record gestures. The dataset contains repetitions of nine gestures performed by 29 subjects, out of which 15 were patients and 14 were healthy controls. The data are presented in an easily accessible format, provided as 3D coordinates of 25 body joints along with the corresponding depth map for each frame. Each movement was annotated with the gesture type, the position of the person performing the gesture (sitting or standing) as well as a correctness label. The data are publicly available and were released with to provide a comprehensive dataset that can be used for assessing the performance of different patients while performing simple movements in a rehabilitation setting and for comparing these movements with a control group of healthy individuals.

A possible billion-year-old holozoan with differentiated multicellularity

Sediments of the Torridonian sequence of the Northwest Scottish Highlands contain a wide array of microfossils, documenting life in a non-marine setting a billion years ago (1 Ga).1-4 Phosphate nodules from the Diabaig Formation at Loch Torridon preserve microorganisms with cellular-level fidelity,5,6 allowing for partial reconstruction of the developmental stages of a new organism, Bicellum brasieri gen. et sp. nov. The mature form of Bicellum consists of a solid, spherical ball of tightly packed cells (a stereoblast) of isodiametric cells enclosed in a monolayer of elongated, sausage-shaped cells. However, two populations of naked stereoblasts show mixed cell shapes, which we infer to indicate incipient development of elongated cells that were migrating to the periphery of the cell mass. These simple morphogenetic movements could be explained by differential cell-cell adhesion.7,8 In fact, the basic morphology of Bicellum is topologically similar to that of experimentally produced cell masses that were shown to spontaneously segregate into two distinct domains based on differential cadherin-based cell adhesion.9 The lack of rigid cell walls in the stereoblast renders an algal affinity for Bicellum unlikely: its overall morphology is more consistent with a holozoan origin. Unicellular holozoans are known today to form multicellular stages within complex life cycles,10-13 so the occurrence of such simple levels of transient multicellularity seen here is consistent with a holozoan affinity. Regardless of precise phylogenetic placement, these fossils demonstrate simple cell differentiation and morphogenic processes that are similar to those seen in some metazoans today.

Injury-related fear in athletes returning to sports after anterior cruciate ligament reconstruction - A quantitative content analysis of an open-ended questionnaire

Background/objectiveInjury-related fear during sport activities are major psychological factors inhibiting a person’s return to sports (RTS) following anterior cruciate ligament reconstruction (ACLR). Currently, there are no studies that quantitatively analyse the open-ended questionnaire for knee injury-related fear in post-ACLR athletes.The purpose of this study was to identify knee injury-related fear in athletes who return to ball-centric sports via the use of an open-ended questionnaire. We aimed to determine the main concepts of injury-related fear according to sex, type of sport, and participation level. MethodsIn this study, a quantitative analysis of an open-ended questionnaire was used to examine the type of fear athletes experience after returning to ball-centric sports. The RTS and fear questionnaire collected open-ended questionnaire to knee injury-related fear during sport activities; this questionnaire was completed at the outpatient visit post-RTS. Quantitative content analysis was performed to extract frequently occurring words from the responses to the questionnaire to create a co-occurrence network. The resulting co-occurrence network and extracted words were used to create concepts regarding knee injury-related fear. The relationship between each concept and subject demographics (sex, returned sports events, and participation level) were analysed using the chi-squared test. ResultsFifty-four athletes (30 females and 24 males) aged 16–45 [median age: 21.2; interquartile range (IQR): 11.0] years with an average RTS of 8.0 (IQR: 3.3) months from ACLR participated in the study. A total of 79 responses were included in the analysis. The knee injury-related fear can be summarized as follows: (1) Quick response to the opponent; (2) Ball-related play; (3) Jump-landing; (4) Contact; (5) Loss of balance; and (6) Athletic movement. Chi-squared tests showed that athletes participating in sport events with potential contact with an opponent (soccer, futsal, basketball, handball, lacrosse, and ultimate (frisbee)) were more likely to experience fear in quick response to the opponent (P < 0.01, adjusted residual = 2.943, ϕ = 0.301). ConclusionThe knee injury-related fear can be summarized into six concepts. Post-ACLR athletes participating in ball-centric sports need to assess fear in situations such as quick responses to the opponent’s movements and ball-related play, in addition to simple movements such as jumping, cutting, and contact.

Profesor Andrzej Grębecki (1934-2021) - badacz fizjologii ruchu komórek, nauczyciel, wychowawca

14 stycznia 2021 r. po długiej chorobie odszedł profesor Andrzej Grębecki wybitny biolog komórki, zasłużony dla nauki w Polsce i na świecie, nauczyciel i wychowawca. Profesor Andrzej Grębecki ukończył Wydział Matematyczno-Przyrodniczy Uniwersytetu Łódzkiego w 1952 r., a w 1956 r. obronił pracę doktorską pod kierunkiem prof. Jana Dembowskiego. Profesor Grębecki przez wiele lat (1973-2002) kierował Pracownią Morfodynamiki Prostych Systemów Ruchowych w Zakładzie Biologii Komórki, Instytutu Nenckiego PAN. Ponadto aktywnie uczestniczył w życiu Instytutu, w którym m.in. pełnił funkcję zastępcy dyrektora d/s naukowych (1975-1981) oraz kierownika studium doktoranckiego (1975-1979). Przez dwie kadencje w latach 1984-1989 był przewodniczącym Rady Naukowej Instytutu Nenckiego. Profesor Grębecki w latach 1984-1989 był członkiem Rady Polskiej Sieci Biologii Komórkowej i Molekularnej UNESCO, a 1993-1997 członkiem International Commission of Protozoology. Zainteresowania naukowe profesora Grębeckiego skupiały się na badaniu mechanizmów ruchu komórek. Był On autorem ponad 160 opublikowanych pozycji naukowych, obejmujących pierwsze w literaturze prace o roli wapnia w regulacji ruchu rzęskowego. Następnie swoje zainteresowania naukowe profesor Grębecki skupił na badaniach fizjologii ruchu amebowego, których wyniki publikował w bardzo prestiżowych czasopismach międzynarodowych: m.in. Journal of Cell Science, European Journal of Cell Biology, Cell Biology International Reports. Główne założenia dotyczące teorii ogólnego skurczu kortykalnego zawarł w obszernej monografii ?Membrane and cytoskeleton flow in motile cells with emphasis on the contribution of free-living Amoebae?, opublikowanej w International Review of Cytology (1994). Dowodem międzynarodowego uznania dorobku profesora Grębeckiego było jego członkostwo w pracy komitetów redakcyjnych międzynarodowych czasopism naukowych: Acta Protozool. (Warszawa), Eur.J.Protistol. (Stuttgart) i Protistology (Omsk). Za swoje osiągnięcia naukowe i organizacyjne był wielokrotnie nagradzany wyróżnieniami i odznaczeniami państwowymi (m.in. Krzyż Oficerski Orderu Odrodzenia Polski - 1998).

Cortical representations of phantom movements in lower limb amputees.

Understanding how sensorimotor cortex (SMC) organization relates to limb loss has major clinical implications, as cortical activity associated with phantom hand movements has been shown to predict phantom pain reports. Critically, earlier studies have largely focused on upper limb amputees; far less is known regarding SMC activity in lower limb amputees, despite the fact that this population comprises the majority of major limb loss cases. We aimed to characterize BOLD fMRI responses associated with phantom and sound limb movements to test the hypothesis that SMC organization is preserved in individuals with lower limb loss. Individuals with unilateral or bilateral lower limb loss underwent fMRI scans as they performed simple movements of their sound or phantom limbs. We observed that voluntary movements of the sound and phantom ankles were associated with BOLD signal changes in medial and superior portions of the precentral and postcentral gyri. In both hemispheres, contralateral limb movements were associated with greater signal changes compared to ipsilateral limb movements. Hand and mouth movements were associated with distinct activation patterns localized to more lateral SMC regions. We additionally tested whether activations associated with phantom movements related to self-report assessments indexing phantom pain experiences, nonpainful phantom sensations and phantom movement capabilities. We found that responses during phantom ankle movements did not correlate with any of the composite phantom limb indices in our sample. Our collective results reveal that SMC representations of the amputated limb persist and that traditional somatotopic organization is generally preserved in individuals suffering from lower limb loss.

High-Intensity Warm-Up Increases Anaerobic Energy Contribution during 100-m Sprint.

Simple SummaryCertain exercise performances or movements cause sudden changes (or increases) in metabolic response. Track and field running events that require explosive energy in the shortest time, such as a 100-m sprint, need an immediate energy supply. Referring to the relevant studies to date, metabolic responses to submaximal exercise have been well documented, while information on the metabolic responses of short-term sprint performance is relatively insufficient. In this regard, based on the evidence that the human body relies on anaerobic energy metabolism during intense, short-term exercise, we investigated anaerobic energy contributions following the acute effect of a high-intensity warm-up during a 100 m-sprint. The main finding of our study revealed that a high-intensity warm-up (HIW) increases the contribution of the anaerobic system, probably by activating key regulatory enzymes related to anaerobic energy metabolism, compared to a low-intensity warm-up, for a 100-m sprint. Therefore, an HIW is effective in increasing anaerobic energy contribution during a 100-m sprint, which can be a useful strategy for coaches and athletes in the field.This study aimed to evaluate the effects of warm-up intensity on energetic contribution and performance during a 100-m sprint. Ten young male sprinters performed 100-m sprints following both a high-intensity warm-up (HIW) and a low-intensity warm-up (LIW). Both the HIW and LIW were included in common baseline warm-ups and interventional warm-ups (eight 60-m runs, HIW; 60 to 95%, LIW; 40% alone). Blood lactate concentration [La−], time trial, and oxygen uptake (VO2) were measured. The different energy system contribution was calculated by using physiological variables. [La−1]Max following HIW was significantly higher than in LIW (11.86 ± 2.52 vs. 9.24 ± 1.61 mmol·L−1; p < 0.01, respectively). The 100-m sprint time trial was not significantly different between HIW and LIW (11.83 ± 0.57 vs. 12.10 ± 0.63 s; p > 0.05, respectively). The relative (%) phosphagen system contribution was higher in the HIW compared to the LIW (70 vs. 61%; p < 0.01, respectively). These results indicate that an HIW increases phosphagen and glycolytic system contributions as compared to an LIW for the 100-m sprint. Furthermore, an HIW prior to short-term intense exercise has no effect on a 100-m sprint time trial; however, it tends to improve times (decreased 100-m time trial; −0.27 s in HIW vs. LIW).

Effects on Motor Control of Personalized Neuromodulation Against Multiple Sclerosis Fatigue.

Fatigue is a hidden symptom of Multiple Sclerosis (MS) disease that nevertheless impacts severely on patients' everyday life. Evidence indicates the involvement of the sensorimotor network and its inter-nodes communication at the basis of this symptom. Two randomized controlled trials (RCTs) showed that the personalized neuromodulation called Fatigue Relief in Multiple Sclerosis (FaReMuS) efficaciously fights multiple sclerosis (MS) fatigue. By this Proof of Concept study, we tested whether FaReMuS reverts the alteration of the brain-muscular synchronization previously observed occurring with fatigue. The cortico muscular coherence (CMC) was studied in 11 patients before and after FaReMuS, a 5-day tDCS (1.5mA, 15min per day) anodal over the whole body's somatosensory representation (S1) via a personalized MRI-based electrode (35 cm2) against the occipital cathode (70 cm2). Before FaReMuS, the CMC was observed at a mean frequency of 31.5 ± 1.6Hz (gamma-band) and positively correlated with the level of fatigue (p = .027). After FaReMuS, fatigue reduced in average of 28% ± 33% the baseline level, and the CMC frequency reduced to 26.6 ± 1.5Hz (p = .022), thus forthcoming the physiological beta-band as observed in healthy people. The personalized S1 neuromodulation treatment, ameliorating the central-peripheral communication that subtends simple everyday movements, supports the appropriateness of neuromodulations aiming at increasing the parietal excitability in fighting MS fatigue. The relationship between central-peripheral features and fatigue profile strengthens a central more than peripheral origin of the symptom.