Motor Control and Learning
Abstract
Motor Control and Learning focuses on the effects of development, aging, and practice on the control of human voluntary movement. These issues have been at the center of attention of the motor control community, but no book until now has addressed all of these issues under one cover in the context of contemporary views on the control of human voluntary movement. This book emphasizes the links between progress in basic motor control research and applied areas such as motor disorders and motor rehabilitation.
Contributors are established scientists in the areas of both theoretical/experimental motor control and its applications. The chapters focus more on large, general issues than on their particular research. As a result, Motor Control and Learning is relevant to both professionals in the areas of motor control, movement disorders, and motor rehabilitation, and to students who are starting their careers in one of these actively developed areas.
Dr. Mark L. Latash is Professor of Kinesiology at the Pennsylvania State University. Dr. Francis G. Lestienne is Professor and Director of the Center for Science and Technology in Physical Activity and Sports at the Université de Caen Basse-Normandie, France.
Chapters (3)
The task of rhythmically bouncing a ball in the air serves as a model system that addresses many fundamental questions of coordination and perceptual control of actions. The task is simplified such that ball and racket movements are constrained to the vertical direction and the ball cannot be lost. As such, a discrete nonlinear model for the kinematics of periodic racket motions and ballistic ball flight between ball-racket contacts was formulated which permitted a set of analyses and predictions. Most centrally, linear stability analysis predicts that the racket trajectory should be decelerating prior to ball contact in order to guarantee dynamically stable performance. Such solutions imply that small perturbations need not be explicitly corrected for and therefore provide a computationally efficient solution. Four quantitative predictions were derived from a deterministic and a stochastic version of the model and were experimentally tested. Results support that human actors sense and make use of the stability properties of task. However, when single larger perturbations arise, human actors are able to adjust their racket trajectory to correct for errors and maintain a stable bouncing pattern.
The dynamical systems underlying the performance and learning of skilled behaviors can be analyzed in terms of state-, parameter-, and graph-dynamics. We review these concepts and then focus on the manner in which variation in dynamical graph structure can be used to explicate the temporal patterning of speech. Simulations are presented of speech gestural sequences using the task-dynamic model of speech production, and the importance of system graphs in shaping intergestural relative phasing patterns (both their mean values and their variability) within and between syllables is highlighted.
Four spontaneous mutations with cerebellar atrophy exhibit ataxia and deficits in motor coordination tasks requiring balance and equilibrium. These mutants were compared to their respective controls for regional brain metabolism assessed by histochemical staining of the mitochondrial enzyme, cytochrome oxidase (CO). The enzymatic activity of Grid2Lc, Grid2ho, Rorasg, and Relnrl mutants was altered in cerebellum and cerebellar-related pathways at brainstem, midbrain, and telencephalic levels. The CO activity changes in cerebellar cortex and deep cerebellar nuclei as well as some cerebellar-related regions were linearly correlated with motor performance in stationary beam and rotorod tasks of Grid2Lc, Rorasg, and Relnrl mutants. These results indicate that in addition to its relation to neural activity, CO staining can be used as a predictor of motor capacity.
... Children with developmental coordination disorder (DCD) struggle with many motor skills incorporating a visual component, including impairment of eye-limb coordination (e.g., grasping objects, reading and writing) and an increased frequency of bumping into things. Such tasks are found to take longer or are done with more difficulty than that of normal peers (Van Waelvelde, De Weerdt, De Cock, & Smits-Engelsman, 2004;Wilmut, Brown, & Wann, 2007), resulting in an overall difficulty with concentration and attention (Latash & Lestienne, 2006;Missiuna, Gaines, Soucie, & McLean, 2006). A commonality in many of the implicated tasks is that they occur at reachable or near-reachable working distances that require good dynamics of refocussing and maintaining clear vision, for which robust ocular accommodation and vergence systems are essential. ...
... Accurate visual control plays an important role in motor skills (Duhamel, Colby, & Goldberg, 1992;Hulme, Smart, Moran, & McKinlay, 1984), including the ability to move in space (Cermak & Larkin, 2002;Latash & Lestienne, 2006), depth perception and figure-ground perception (Latash & Lestienne, 2006). These perceptual abilities require accurate feedback from clear retinal images and appropriate responses to changes in distances (Enright, 1986;Schor, Lott, Pope, & Graham, 1999). ...
... Accurate visual control plays an important role in motor skills (Duhamel, Colby, & Goldberg, 1992;Hulme, Smart, Moran, & McKinlay, 1984), including the ability to move in space (Cermak & Larkin, 2002;Latash & Lestienne, 2006), depth perception and figure-ground perception (Latash & Lestienne, 2006). These perceptual abilities require accurate feedback from clear retinal images and appropriate responses to changes in distances (Enright, 1986;Schor, Lott, Pope, & Graham, 1999). ...
... This claim is in line with previous opinions that motor perceptual ability influences cognitive function, i.e. (1) there is a direct effect and correlation between motor perceptual ability and academic achievement, (2) perceptual motor ability is based on readiness and academic performance. For example, a good synchronization between hands and eyes is a requirement for writing skills [3]. Siedentop, Herkowitz and Rink [4] suggest that motor perceptual development is closely related to the range of basic skills or the crucial abilities in building a strong foundation for high learning achievement. ...
... The research scheme is presented in Figure 3. The research and development stages of Gall & Borg [5] cover the following: (1) assessing the need to identify objectives; (2) conducting instructional analysis; (3) analyzing students and materials; (4) writing performance goals; (5) developing assessment instruments; (6) developing instructional strategies; (7) developing and selecting instructional materials; (8) designing and conducting formative evaluation of learning; (9) revising instructions; and (10) designing and conducting summative evaluation. By through those ten steps, an effective and well-implemented final product can be produced. ...
... The functional recovery of these patients may not come from muscle activation and increased muscle strength, but rather from repeated postural and motor training that corrects motor pattern of multiple muscles, segments, and limbs. Neurodevelopment treatment, proprioceptive neuromuscular facilitation, and motor relearning training all belong to this treatment modality [4][5][6]. It is important to distinguish the networks of different neuromuscular control models and find their characteristics to enhance the therapeutic effects. ...
Background
There is currently no objective and accurate clinical assessment of reticular neuromuscular control in healthy subjects or patients with upper motor neuron injury. As a result, clinical dysfunctions of neuromuscular control could just be semi-quantified, efficacies and mechanisms of various therapies for neuromuscular control improving are difficult to verify.
Methods
Fourteen healthy participants were required to maintain standing balance in the kinetostatics model of Gusu Constraint Standing Training (GCST). A backward and upward constraint force was applied to their trunk at 0°, 20° and 25°, respectively. The multiplex recurrence network (MRN) was applied to analyze the surface electromyography signals of 16 muscles of bilateral lower limbs during the tests. Different levels of MRN network indices were utilized to assess reticular neuromuscular control.
Results
Compared with the 0° test, the MRN indices related to muscle coordination of bilateral lower limbs, of unilateral lower limb and of inter limbs showed significant increase when participants stood in 20° and 25° tests (P < 0.05). The indices related to muscle contribution of gluteal, anterior thigh and calf muscles significantly increased when participants stood in 20° and 25° tests (P < 0.05).
Conclusions
This study applied the dynamical network indices of MRN to analyze the changes of neuromuscular control of lower limbs of healthy participants in the kinetostatics model of GCST. Results showed that the overall coordination of lower limb muscles would be significantly enhanced during performing GCST, partly by the enhancement of neuromuscular control of single lower limb, and partly by the enhancement of joint control across lower limbs. In particular, the muscles in buttocks, anterior thighs and calves played a more important role in the overall coordination, and their involvement was significantly increased. The MRN could provide details of control at the bilateral lower limbs, unilateral lower limb, inter limbs, and single muscle levels, and has the potential to be a new tool for assessing the reticular neuromuscular control.
Trial registration ChiCTR2100055090
... A méretelv szerint természetes körülmények között az erőkifejtés növekedésével több izomrost és ezzel egyidejűleg magasabb frekvenciájú izomrostok is bekapcsolódnak [12][13][14][15][16][17][18][19], viszont az erőkifejtés nagyságának növelésére van egy másik idegrendszeri stratégia is. Abban az esetben, ha a központi idegrendszer már nem tud több izomrostot aktivációra bírni, a már bekapcsolt izmokhoz küldött ingerek frekvenciáját fogja változtatni [20]. Ha a terhelés nagy intenzitású, következésképpen az izomaktiváció szintje is nagy, a legtöbb rost aktív. ...
Introduction:
In patients with cancer, loss of muscle mass is observed in many cases and tumour types. This can lead to a drastic deterioration in the patient's quality of life, with the inability to support themselves. Nowadays, in addition to primary treatment of the tumour, physical training of patients has become a priority in order to maintain their quality of life. One key to this is resistance training to prevent sudden muscle loss, which the patient can do alongside primary treatment, and isometric training may be one option.
Objective:
Our aim was to measure the activation frequency characteristics of the biceps brachii muscle in our subjects during a fatigue protocol while creating a constant controlled isometric tension in the muscle.
Method:
19 healthy university students participated in our study. After determining the dominant side, the subjects' single repetition maximum was assessed using the GymAware RS tool and then 65% and 85% of this was calculated. We placed electrodes on the biceps brachii muscle and had them hold the weight at 65% and 85% until full fatigue. Immediately afterwards, subjects performed an isometric maximal contraction (Imax). The measured electromyography recordings were divided into 3 equal parts, then the first, middle and last 3 s (W1, W2, W3) were analyzed.
Results:
Our results show that, consistent with fatigue, at both 1RM 65% and 1RM 85% load, the activity of the low-frequency motor units increases, while the activation of the high-frequency motor units decreases.
Discussion:
The present study is consistent with our previous study.
Conclusion:
Our test protocol is not suitable for prolonged activation of high-frequency motor units because the activity of high-frequency motor units decreases over time. Orv Hetil. 2023; 164(10): 376-382.
... Previous studies proved that the TRX exercises could increase the balance and stability. Balance controlled the bodyweight in dynamic and static condition [10]. Whereas stability defined the balance condition toward inside and outside pressure force and the pressure on muscle tissue and joints [9]. ...
Cel: Celem tego badania jest przeanalizowanie i porównanie skuteczności ćwiczenia całkowitego oporu ciała – wznoszenia, opadania i stałego obciążenia, w zwiększaniu siły, mocy i stabilności. Metodologia: W badaniu wykorzystano metodę ilościową z quasi-eksperymentalnymi technikami projektowania. Wyniki: Wyniki pokazały, że: 1) w rosnącej grupie siła mięśni nóg miała najwyższy odsetek w porównaniu z innymi zmiennymi dla 22%, podczas gdy siła mięśni nóg miała najniższy wynik dla 12%; 2) w grupie malejącej siła mięśni ramienia miała najwyższy wynik dla 36% niż inne zmienne, a siła mięśni nogi miała najniższy wynik dla 16%; 3) w grupie o stałym obciążeniu siła mięśni ramienia wzrosła o 15%, siła mięśni nóg o 14%, 12% dla siły mięśni ramion, 8% dla siły i stabilności mięśni nóg lub równowagi ciała o 35%. Wniosek: Między grupami obciążeń wstępujących, opadających i stałych występowała znacząca skuteczność pod względem zwiększania siły, mocy i stabilności. Grupa opadająca i o stałym obciążeniu miała większy lub bardziej skuteczny wpływ na zwiększenie siły mięśni ramienia niż grupa rosnąca.
... 8 This change in thinking is coupled with a greater understanding of motor learning mechanisms, with the use of repetitive, task-specific movements beneficial to restructuring motor pathways. 9,10 Functional gait training allows for repetition of motor task to drive skill acquisition. 11,12 Targeting improved walking ability, with training, may lead to gains in increased independence and follow with increased participation in daily life. ...
Aim:
The aim of this systematic review was to investigate the effects of functional gait training on walking ability in children and young adults with cerebral palsy (CP).
Method:
The review was conducted using standardized methodology, searching four electronic databases (PubMed, Embase, CINAHL, Web of Science) for relevant literature published between January 1980 and January 2017. Included studies involved training with a focus on actively practising the task of walking as an intervention while reporting outcome measures relating to walking ability.
Results:
Forty-one studies were identified, with 11 randomized controlled trials included. There is strong evidence that functional gait training results in clinically important benefits for children and young adults with CP, with a therapeutic goal of improved walking speed. Functional gait training was found to have a moderate positive effect on walking speed over standard physical therapy (effect size 0.79, p=0.04). Further, there is weaker yet relatively consistent evidence that functional gait training can also benefit walking endurance and gait-related gross motor function.
Interpretation:
There is promising evidence that functional gait training is a safe, feasible, and effective intervention to target improved walking ability in children and young adults with CP. The addition of virtual reality and biofeedback can increase patient engagement and magnify effects.
What this paper adds:
Functional gait training is a safe, feasible, and effective intervention to improve walking ability. Functional gait training shows larger positive effects on walking speed than standard physical therapy. Walking endurance and gait-related gross motor function can also benefit from functional gait training. Addition of virtual reality and biofeedback shows promise to increase engagement and improve outcomes.
... The trend seen in Figure 11 is to be expected as when one gets older, motor control function of the hands begins to drop, and physical conditions such as arthritis tend to start manifesting themselves. 20 While all the dexterity data collected are useful, as it verified that age has a big effect on the ability to perform fine-finger movements, it was still unclear how that could be linked to the ability of the Figure 11. Graph showing the relationship between age and dexterity. ...
Few previous work has been undertaken in understanding issues surrounding dexterity and access to packaging. Researchers had access to users who had known dexterity issues and had been advised by their doctor to decant their medication into bottles rather than use unit-dose blister packaging. Hence, it was decided to use a range of techniques to understand this problem. It was further proposed to develop a methodology by which the relative performance of packaging could be assessed with respect to dexterity issues. In this study, there were three objectives to carry out: motion-capture analysis, grip analysis and dexterity analysis when opening the blister packs. Motion capture was carried out on eight people aged 55 years and older, a classification of the grips used when opening blister packs was performed on 57 people aged 18 years and older, and a Purdue Pegboard test was administered to 54 people aged 18 years and older. It was found out that there were four common types of grips used, out of which two of the grips were used by more than 88% of participants. With the motion capture, it was found that each grip and their various associated techniques were compared with each other. Grip 2 utilized the least finger movement. Using the dexterity test results, it was corroborated that dexterity decreases with age, and an accessibility score was developed that can be used by pack designers and manufacturers to assess pack performance. Future work is proposed to develop this methodology further. Copyright © 2013 John Wiley & Sons, Ltd.
... Further, we explored the possibility that once the visual coupling was removed, individual movements, although no longer synchronized, might remain influenced by the social encounter after it was over, thereby implicating memory as a distinguishing feature of human selforganizing systems. Just as kinematic studies have elucidated the neural basis of motor control (see, e.g., contributions in Latash & Lestienne, 2006) the present work sets the stage and provides new methods for neurophysiological investigations of social interaction. So far the latter have tended to assess the behavioral actions of pairs is an unusual piece of classical music in which the conductor leads not only the orchestra but also the audience. ...
For more than 20 years, coordination dynamics have provided research on human movement science with new views about the nonlinear relationships between behavioral and neural dynamics. A number of studies across various experimental settings including bimanual, postural or interpersonal coordination, and also coordination between movements of a limb and an external event in the environment revealed the selforganized nature of human coordination. Here we review an extensive body of literature – in the human movement science and the neuroscience fields – that has investigated the coordination dynamics of brain and behavior when individuals are involved in two rhythmic coordination patterns: synchronization (onthe- beat movements) and syncopation (in-between beats movements). When the frequency of movement approaches 2 Hz, the syncopation mode is destabilized and synchronization is spontaneously adopted. The abrupt change between the two patterns illustrates a phenomenon known as non-equilibrium phase transition. Phase transitions offer a novel entry point into the investigation of pattern formation (and dissolution) at both the behavioral and the cerebral levels as they illustrate the loss of stability of the system. Brain imaging methods (MEG, EEG and fMRI) were used to reveal the neural signatures of (in)stability underlying the differences between behavioral coordination patterns, and pointed at the role of self-organization and metastability principles in brain functioning. Relationships between behavioral and brain dynamics can therefore be investigated within a unified empirical and theoretical framework. Depuis plus de deux décennies, la théorie des systèmes dynamiques a permis de considérer sous un jour nouveau les liens entre les coordinations sensorimotrices chez l'humain et la dynamique cérébrale qui leur est associée. De multiples travaux dans des domaines aussi variés que les coordinations bimanuelles, posturales, interpersonnelles, ou encore les coordinations entre un individu et son environnement ont montré que le comportement, la cognition et le cerveau humains sont fonctionnellement sous-tendus par la théorie des systèmes dynamiques non linéaires. Dans cette revue de la littérature, nous présentons un ensemble de travaux conduits autour de la réalisation de deux patrons de coordination rythmique : la synchronisation (coordonner un mouvement sur chaque événement d'une stimulation) et la syncopation (coordonner un mouvement entre deux événements d'une stimulation). A des fréquences de mouvement supérieures à 2 Hz, la syncopation devient impossible et l'on adopte spontanément la synchronisation. Ce changement abrupt entre syncopation et synchronisation révèle une réorganisation comportementale qualifiée de transition de phase (loin de l'équilibre). Il permet l'étude opérationnelle de l'adoption spontanée (et de l'abandon) de patrons de coordination aux niveaux comportemental (cinématique) et cérébral. Les nouvelles techniques d'imagerie cérébrale fonctionnelle (EEG, MEG et IRMf) ont récemment permis de mettre en évidence la signature de cette différence de stabilité comportementale au niveau de l'activité du cerveau, et indiquent que son fonctionnement est lui aussi sous-tendu par le principe d'autoorganisation. Les liens entre dynamiques comportementale et cérébrale peuvent donc être abordés au sein d'un cadre expérimental et théorique unifié afin de mieux comprendre le caractère métastable du cerveau humain, à savoir ses propriétés d'intégration (globale) et de ségrégation (locale).
... Further, we explored the possibility that once the visual coupling was removed, individual movements, although no longer synchronized, might remain influenced by the social encounter after it was over, thereby implicating memory as a distinguishing feature of human selforganizing systems. Just as kinematic studies have elucidated the neural basis of motor control (see, e.g., contributions in Latash & Lestienne, 2006) the present work sets the stage and provides new methods for neurophysiological investigations of social interaction. So far the latter have tended to assess the behavioral actions of pairs is an unusual piece of classical music in which the conductor leads not only the orchestra but also the audience. ...
Spontaneous social coordination has been extensively described in natural settings but so far no controlled methodological approaches have been employed that systematically advance investigations into the possible self-organized nature of bond formation and dissolution between humans. We hypothesized that, under certain contexts, spontaneous synchrony-a well-described phenomenon in biological and physical settings-could emerge spontaneously between humans as a result of information exchange. Here, a new way to quantify interpersonal interactions in real time is proposed. In a simple experimental paradigm, pairs of participants facing each other were required to actively produce actions, while provided (or not) with the vision of similar actions being performed by someone else. New indices of interpersonal coordination, inspired by the theoretical framework of coordination dynamics (based on relative phase and frequency overlap between movements of individuals forming a pair) were developed and used. Results revealed that spontaneous phase synchrony (i.e., unintentional in-phase coordinated behavior) between two people emerges as soon as they exchange visual information, even if they are not explicitly instructed to coordinate with each other. Using the same tools, we also quantified the degree to which the behavior of each individual remained influenced by the social encounter even after information exchange had been removed, apparently a kind of social memory.
Способность к усвоению ритма – это важный фактор в развитии, выполнении движения и обучении двигательным навыкам (Zachopoulou E. et al., 2000). Наличие этой способности улучшает понимание, запоминание и представление движения с точки
зрения его временно́й структуры. Способность к усвоению ритма и к организации ритмических действий часто рассматривается как составная часть общих координационных способностей. Кроме того, в различных исследованиях показано, что способность к сенсомоторной синхронизации тесно связана с когнитивными, в том числе исполнительными функциями, а также речевыми процессами.
В наших исследованиях, проведенных в ЛРНЦ "Русское поле", было показано, что частота произвольно выбираемого ритма не зависит от возраста и степени поражения ЦНС. Частота максимального теппинга растет с возрастом, при этом она ниже у детей, завершивших лечение по поводу опухолей ЗЧЯ. Эти дети демонстрируют повышенную истощаемость и меньшую силу
нервной системы. Чувство ритма и способность к слухомоторной синхронизации страдают при облучении, химиотерапии и хирургическом
удалении части мозжечка. Больше всего у детей, завершивших лечение от опухолей, страдают те функции, в которых задействованы когнитивные
Aim
The neurocognitive basis of Developmental Coordination Disorder (DCD; or motor clumsiness) remains an issue of continued debate. This combined systematic review and meta-analysis provides a synthesis of recent experimental studies on the motor control, cognitive, and neural underpinnings of DCD.
Methods
The review included all published work conducted since September 2016 and up to April 2021. One-hundred papers with a DCD-Control comparison were included, with 1,374 effect sizes entered into a multi-level meta-analysis.
Results
The most profound deficits were shown in: voluntary gaze control during movement; cognitive-motor integration; practice-/context-dependent motor learning; internal modeling; more variable movement kinematics/kinetics; larger safety margins when locomoting, and atypical neural structure and function across sensori-motor and prefrontal regions.
Interpretation
Taken together, these results on DCD suggest fundamental deficits in visual-motor mapping and cognitive-motor integration, and abnormal maturation of motor networks, but also areas of pragmatic compensation for motor control deficits. Implications for current theory, future research, and evidence-based practice are discussed.
Systematic Review Registration
PROSPERO, identifier: CRD42020185444.
Objective:
To investigate the immediate response to avatar-based biofeedback on three clinically important gait parameters; step length, knee extension and ankle power, in children with cerebral palsy (CP).
Design:
Repeated measures design.
Setting:
Rehabilitation clinic.
Participants:
Twenty-two children with spastic paresis (10y4m±3y1m), able to walk without assistive devices.
Intervention:
Children walked on a treadmill with virtual reality environment. Following baseline gait analysis, they were challenged to improve aspects of gait. Children visualized themselves as an avatar, representing movement in real-time. They underwent a series of two-minute trials receiving avatar based biofeedback on step length, knee extension and ankle power. To investigate optimization of biofeedback visualization, additional trials in which knee extension was visualized as a simple bar with no avatar; and a further trial with avatar alone, and no specific biofeedback were carried out.
Main outcome measures:
Gait pattern, as measured by joint angles, powers and spatiotemporal parameters, were compared between baseline and biofeedback trials.
Results:
Participants were able to adapt gait pattern with biofeedback, in an immediate response, reaching large increases in ankle power generation at push-off (37.7%) and clinically important improvements in knee extension (7.4o) and step length (12.7%). Biofeedback on one parameter had indirect influence on other aspects of gait.
Conclusion:
Children with CP show capacity in motor function to achieve improvements in clinically important aspects of gait. Visualizing biofeedback with an avatar was subjectively preferential compared to a simplified bar presentation of knee angle. Future studies are required to investigate if observed transient effects of biofeedback can be retained with prolonged training to test whether biofeedback-based gait training may be implemented as a therapy tool.
Aims:
Compare haptic exploratory procedures (EPs) and exploratory movements (EMs) of children. This study also tested the interrater reliability of a novel digital recording method.
Methods:
Participants were 31 children with typical development (TD) (aged 6 years 1 month to 15 years 9 months; 14 male) and 23 children with spastic unilateral cerebral palsy (CP) (aged 6 years to 15 years 5 months; 13 males; right hemiplegia, n = 12).
Results:
There were no statistically significant differences between groups for expected EP (p = .15), additional EPs (p = .78), or EMs (p = .69) but there was for mean duration of exploration (p < .001) and accuracy (p < .001). This suggests that although children with CP performed similar haptic EPs for each object as children with TD, they took more time and were less accurate in their identification. There was substantial agreement between the two raters' observations of expected EP, κ = .64, p < .0005.
Conclusion:
Children with CP performed similar haptic EPs as their TD peers. However, despite similarities, the results indicate that for children with CP manual ability was not the primary determinant of accuracy or speed of identification. This study provides evidence for a reliable method of recording haptic EPs.
Objective analysis of hand and finger kinematics is important to increase understanding of hand function and to quantify motor symptoms for clinical diagnosis. The aim of this paper is to compare a new 3D measurement system containing multiple miniature inertial sensors (PowerGlove) with an opto-electronic marker system during specific finger tasks in three healthy subjects. Various finger movements tasks were performed: flexion, fast flexion, tapping, hand open/closing, ab/adduction and circular pointing. 3D joint angles of the index finger joints and position of the thumb and index were compared between systems. Median root mean square differences of the main joint angles of interest ranged between 3.3 and 8.4deg. Largest differences were found in fast and circular pointing tasks, mainly in range of motion. Smallest differences for all 3D joint angles were observed in the flexion tasks. For fast finger tapping, the thumb/index amplitude showed a median difference of 15.8mm. Differences could be explained by skin movement artifacts caused by relative marker movements of the marker system, particularly during fast tasks; large movement accelerations and angular velocities which exceeded the range of the inertial sensors; and by differences in segment calibrations between systems. The PowerGlove is a system that can be of value to measure 3D hand and finger kinematics and positions in an ambulatory setting. The reported differences need to be taken into account when applying the system in studies understanding the hand function and quantifying hand motor symptoms in clinical practice.
El interés por el entrenamiento integrado es creciente y para aumentar su eficacia resulta clave conocer cómo se produce el proceso de integración en los sistemas vivos. Por lo general, se suele asumir que el tipo de integración que se da en el organismo y entre los componentes del entrenamiento es sumatoria y lineal; es decir, está caracterizada por relaciones proporcionales, fijas e invariables en el tiempo, como las que se dan en cualquier artilugio técnico. Este modelo de integración, basado en la cibernética clásica, contrasta con el modelo de integración dinámica y no lineal, asentado en la neurociencia, la teoría de sistemas dinámicos no lineales, y la dinámica ecológica. Algunos principios de la integración dinámica y no lineal como la autoorganización, su carácter no proporcional y no consciente y su integración contextual en diferentes escalas acostumbran a ignorarse sistemáticamente en las metodologías de entrenamiento más habituales. El objetivo de este trabajo es presentar los principios dinámicos del entrenamiento integrado para promover la emergencia de metodologías más eficaces y eficientes a la vez que más respetuosas con los deportistas y los equipos.
Women’s Downhill podium of Sochi in 2014 is likely to remain in the Olympic Winter Games history [1]. After 100 s at Rosa Khutor’s slope, Dominique Gisin, Tina Maze, and Lara Gut arrived at the finish line wrapped in just 10/100 of a second. More than 2700m of race, with several turns and jumps; and the difference between first and third place was less than 3m, i.e. in the order of 1%! Even more extraordinary was the result of the first two Athletes: exactly the same time, giving to the annals the first ex aequo gold medal of Winter Olympics. The same result, accurate to a hundredth of a second, was obtained by athletes differing in ages, nationalities, anthropometric characteristics, technical equipments, and race number. In Winter Sports and Olympics it was not the first time, in different disciplines. Even without these exceptional events, in modern sports differences between top athletes are almost minimal. It often happens that long races like the 50 km Cross Country Skiing of Vancouver 2010 end at photo finish: achieving the podium is often a matter of hundredths of second or centimetres. Athletes, coaches, trainers, researchers, engineers, and practitioners ask: where are the differences? It is still possible to improve [2, 3]?
L’interes per l’entrenament integrat es creixent i per augmentar la seva eficacia resulta clau coneixer com es produeix el proces d’integracio en els sistemes vius. Generalment, se sol assumir que el tipus d’integracio que es dona en l’organisme i entre els components de l’entrenament es sumatoria i lineal; es a dir, esta caracteritzada per relacions proporcionals, fixes i invariables en el temps, com les que es donen en qualsevol artefacte tecnic. Aquest model d’integracio, basat en la cibernetica classica, contrasta amb el model d’integracio dinamica i no lineal, assentat en la neurociencia, la teoria de sistemes dinamics no lineals i la dinamica ecologica. Alguns principis de la integracio dinamica i no lineal com l’autoorganitzacio, el seu caracter no proporcional i no conscient i la seva integracio contextual en diferents escales acostumen a ignorar-se sistematicament en les metodologies d’entrenament mes habituals. L’objectiu d’aquest treball es presentar els principis dinamics de l’entrenament integrat per promoure l’emergencia de metodologies mes eficaces i eficients i alhora mes respectuoses amb els esportistes i els equips.
Interest in integrated training is growing and to increase its effectiveness it is essential to know how the integration process occurs in living systems. Generally speaking it is usually assumed that the kind of integration which occurs in the body and between the components of training is additive and linear, in other words it is characterised by proportional, fixed and unchanging relationships over time as are found in any technical gadget. This integration model based on classical cybernetics contrasts with the model of nonlinear dynamical integration based on neuroscience, the theory of nonlinear dynamical systems and ecological dynamics. Some principles of nonlinear dynamical integration such as self-organisation, its non-proportional and non-conscious nature and its contextual integration at different scales are often systematically ignored in most common training methodologies. The purpose of this paper is to present the dynamic principles of integrated training to promote the emergence of more effective and efficient methodologies which at the same time are more respectful of athletes and teams.
The interest for the integrated training is growing and to increase its effectiveness is key to know how the integration process is produced in living systems. Generally, it is usually assumed that the type of integration existing in living systems and between training components is additive and linear; i.e., it is characterized by proportional, fixed and invariable relations in time, like those occurring in any technical device. This integration model, based on classical cybernetics, contrasts with the dynamic and nonlinear integration model inspired in neuroscience, nonlinear dynamical systems theory, and ecological dynamics. Some principles of dynamic and nonlinear integration like the self-organization, its non-proportional and non- conscious character and its contextual integration on different scales are usually systematically ignored in the most current training methodologies. The objective of this paper is to present the dynamic principles of integrated training for promoting the emergency of more effective and efficient methodologies while more respectful with athletes and teams.
Language can be viewed as a structuring of cognitive units that can be transmitted among individuals for the purpose of communicating information. Cognitive units stand in specific and systematic relationships with one another, and linguists are interested in the characterization of these units and the nature of these relationships. Both can be examined at various levels of granularity. It has long been observed that languages exhibit distinct patterning of units in syntax and in phonology. This distinction, a universal characteristic of language, is termed duality of patterning (Hockett, 1960). Syntax refers to the structuring of words in sequence via hierarchical organization, where words are meaningful units belonging to an infinitely expandable set. But words also are composed of structured cognitive units. Phonology structures a small, closed set of recombinable, non-meaningful units that compose words (or signs, in the case of signed languages). It is precisely the use of a set of non-meaningful arbitrary discrete units that allows word creation to be productive. In this chapter we outline a proposal that views the evolution of syntax and of phonology as arising from different sources and ultimately converging in a symbiotic relationship. Duality of patterning forms the intellectual basis for this proposal. Grasp and other manual gestures in early hominids are, as Arbib (Chapter 1, this volume) notes, well suited to provide a link from the iconic to the symbolic.
In this study we investigate the articulatory coordination of word initial consonant clusters in Italian. We show that these clusters are generally coordinated in a similar way to clusters in languages with complex syllable onsets, in that the timing of the rightmost consonantal gesture in relation to the vocalic gesture is adjusted according to the number of consonants in the cluster. However, clusters containing a sibilant, /s/ or /z/, are an exception and show a different coordination pattern altogether. Such clusters are referred to as having an 'impure s', mainly as a result of allomorphy of indefinite and definite articles (e.g. il premio, but lo studente). In such cases, the sibilant does not affect the coordination of the remaining consonants, indicating that it may not be part of the syllable onset.
An optimum internal model with constraints is proposed and discussed for the control of a speech robot, which is based on the human-like behavior. The main idea of the study is that the robot movements are carried out in such a way that the length of the path traveled in the internal space, under external acoustical and mechanical constraints, is minimized. This optimum strategy defines the designed internal model, which is responsible for the robot task planning. First, an exact analytical way to deal with the problem is proposed. Next, by using some empirical findings, an approximate solution for the designed internal model is developed. Finally, the implementation of this solution, which is applied to the control of a speech robot, yields interesting results in the field of task-planning strategies, task anticipation (namely, speech coarticulation), and the influence of force on the accuracy of executed tasks.
Postural stability of bulldozer operators after a day of work is investigated. When operators are no longer exposed to whole-body vibration (WBV) generated by their vehicle, their sensorimotor coordination and body representation remain altered. A sensorimotor treatment based on a set of customized voluntary movements is tested to counter and prevent potential post-work accidents due to prolonged exposure to WBV. This treatment includes muscle stretching, joint rotations, and plantar pressures, all known to minimize the deleterious effects of prolonged exposure to mechanical vibrations. The postural stability of participants (drivers; N = 12) was assessed via the area of an ellipse computed from the X and Y displacements of the center-of-pressure (CoP) in the horizontal plane when they executed a simple balance task before driving, after driving, and after driving and having performed the sensorimotor treatment. An ancillary experiment is also reported in which a group of non-driver participants (N = 12) performed the same postural task three times during the same day but without exposure to WBV or the sensorimotor treatment. Prolonged exposure to WBV significantly increased postural instability in bulldozer drivers after they operated their vehicle compared to prior to their day of work. The sensorimotor treatment allowed postural stability to return to a level that was not significantly different from that before driving. The results reveal that (1) the postural system remains perturbed after prolonged exposure to WBV due to operating a bulldozer and (2) treatment immediately after driving provides a "sensorimotor recalibration" and a significant decrease in WBV-induced postural instability. If confirmed in different contexts, the postural re-stabilizing effect of the sensorimotor treatment would constitute a simple, rapid, inexpensive, and efficient means to prevent post-work accidents due to balance-related issues.
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