Search results

1

The influence of tactile feedback on hand movement accuracy

100%

Polechoński J., Olex-Zarychta D.

Human Movement

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2012

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vol. 13

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issue 3

236-241

EN

Purpose. This study aimed at measuring the reaction of the hand when tactile feedback was impaired in upper extremity motor performance in order to empirically evaluate how precision was affected during visually controlled hand and arm movement. Methods. 26 right-handed young male adults were tested with the use of a line tracking task by means of Schuhfried’s Vienna Test System. Tactile feedback during line tracking task was impaired by the use of different gloves: a chirurgical latex glove, a rubber glove and a thick work glove made of soft animal leather. Results. The results found a strong relationship between hand movement accuracy and the degree of tactile impairment; no significant relationship was found between tactile impairment and movement speed. Limiting tactile feedback was found to influence motor task accuracy during local wrist movements (using only the carpal and palm joints), while tasks that allowed global movement (both wrist and forearm) were found to have accuracy influenced only when tactile feedback was highly impaired (line tracking with the thick leather glove). Conclusions. The results have indicated that the role of tactile feedback on accuracy during visually-guided precision movement is far greater than previously reported.

2

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

100%

Latash M.

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EN

This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time.

3

Groin Pain in Athletes – Clinical Experience

100%

Ficek K., Rzepka R., Orawczyk T., Żołnierczyk Z.

Journal of Human Kinetics

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2008

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vol. 19

141-148

EN

Dysfunction of lumbo-pelvic area is a common problem in many sports. Due to insufficient data supporting variables predisposing to lumbo-pelvic dysfunction, and a lack of standards in thorough assessment, understanding the overall problem continues to provide clinical complications; and unfortunately, the prognosis is less than promising. Most often this type of non-contact injury in the groin area is seen in dynamic sports involving running, sprinting, and sports performed over longer time periods, where fatigue plays an important role (soccer, rugby, hockey). There have been proposals in identifying most probable factors influencing the occurrence of pelvic overload injury. Among those we can list: muscle strength and balance, training regimen (including warm-up), fatigue, flexibility, body mechanics, sports specific activities, movement technique, previous injury, and psychological state. During clinical assessment by the physician and physiotherapist, many of these risks of injury factors are found. Currently more attention is given to neuromuscular factors that can affect risk of this pathology.Our clinical experience suggests that poor neuromuscular control and lack of strength may significantly contribute to injury in the lumbo-pelvic and groin area. Certain objective indexes (e.g., hamstrings to quadriceps strength H/Q, stability deficits) can be important indicators of injury risk, as well as guidelines for motor dysfunction recovery.

4

Practice effects on fast and accurate spatially constrained movements

100%

Pereira C. F., Marques I., Okazaki V. H. A.

Human Movement

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2014

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vol. 15

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issue 1

4-11

EN

Purpose. The effects of practice were analyzed in the control of fast and accurate spatially constrained movements. Methods. Twenty men (20-26 years old) evenly divided into an experimental and control group were analyzed in three time periods: pre-test, post-test, and retention. Discrete Aiming Task ver. 2.0 software simulated Fitts’ task (1954) and provided kinematic analysis of mouse cursor movements (displacement, velocity, and acceleration). The task consisted of using the mouse to click on two parallel targets as fast and accurately as possible. Four target widths (W = 2.0, 1.0, 0.5, and 2.5 inches) and three distances between the targets (D = 2.0, 4.0, and 8.0 inches) were used to provide indexes of difficulty (ID) from 1 to 6 bits. The experimental group performed 108 practice trials (three blocks of 36 trials on different days) while the control group had no practice. Results. Movement time (MT) decreased in the experimental group largely due in part to a reduction of time used for feedback. It is suggested that the improvement in performance as a function of practice occurred through the interdependence of programming and the feedback process. As the task was practiced, there was decreased need for feedback due to better pre-programming of the primary submovement and the improved use of sensorial feedback information. This strategy and a lengthened deceleration phase can help explain the paradigm of fast and accurate movement as a result of practice. Conclusions. Despite the improved performance changes as a consequence of practice, Fitts’ Law proved to be robust enough to predict MT as a function of ID.

5

Muscular Activation Patterns in Swimmers with Asymptomatic Shoulder Joint Instability

100%

Santos M. J., Soldado G. C. D., Marconi N. F., Gil A. L.

Human Movement

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2013

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vol. 14

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issue 1

56-63

EN

Purpose. The aim of this study was to investigate the (electromyographic) EMG patterns of the shoulder muscles in asymptomatic swimmers with AGI - atraumatic glenohumeral instability. AGI, one of the most common shoulder disorders in athletes who perform overhead activities, occurs especially among swimmers. AGI usually provokes shoulder pain and secondary impingement syndrome, which might alter glenohumeral and scapular kinematics and change the activity of the shoulder muscles. Alternatively, pain or functional activities might affect EMG patterns in individuals with AGI. Methods. Eight swimmers with AGI and eight healthy swimmers took part in this cross-sectional study. Bilateral and simultaneous shoulder elevations in the scapular plane toward three different target distances were investigated, and the shoulder kinematics and EMG activities of the glenohumeral and scapulothoracic muscles were also collected. Results. No differences in the EMG patterns were found between swimmers with and without AGI in terms of the rate of EMG rise and magnitude. Conclusions. Shoulder instability does not necessarily affect the modulation of the shoulder muscles in swimmers with AGI. Others factors such as laxity in the capsular structures and ligaments may be one of the primary reasons for pain and instability in these athletes.

6

The Impact of Immediate Verbal Feedback on the Improvement of Swimming Technique

100%

Zatoń K., Szczepan S.

Journal of Human Kinetics

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2014

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vol. 41

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issue 1

143-154

EN

The present research attempts to ascertain the impact of immediate verbal feedback (IVF) on modifications of stroke length (SL). In all swimming styles, stroke length is considered an essential kinematic parameter of the swimming cycle. It is important for swimming mechanics and energetics. If SL shortens while the stroke rate (SR) remains unchanged or decreases, the temporal-spatial structure of swimming is considered erroneous. It results in a lower swimming velocity. Our research included 64 subjects, who were divided into two groups: the experimental - E (n=32) and the control - C (n=32) groups. A pretest and a post-test were conducted. The subjects swam the front crawl over the test distance of 25m at Vmax. Only the E group subjects were provided with IVF aiming to increase their SL. All tests were filmed by two cameras (50 samples•s-1). The kinematic parameters of the swimming cycle were analyzed using the SIMI Reality Motion Systems 2D software (SIMI Reality Motion Systems 2D GmbH, Germany). The movement analysis allowed to determine the average horizontal swimming velocity over 15 meters. The repeated measures analysis of variance ANOVA with a post-hoc Tukey range test demonstrated statistically significant (p<0.05) differences between the two groups in terms of SL and swimming velocity. IVF brought about a 6.93% (Simi method) and a 5.09% (Hay method) increase in SL, as well as a 2.92% increase in swimming velocity.

7

Motor Control Mechanisms and the Practice of Krav Maga - a Narrative Analysis

100%

Mor G.

Central European Journal of Sport Sciences and Medicine

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2021

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vol. 35

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issue 3

17-25

EN

Krav Maga (‘contact combat’) is an Israeli hand-to-hand combat discipline that originated in the early 19th century in response to life-threatening conflicts. Today, Krav Maga is a popular self-defense and martial art discipline practiced and taught throughout the world. One of the key features of Krav Maga that distinguishes it from other combat disciplines is its dependence on reflexive defense – a natural and immediate defensive reaction. However, the relevant literature has not discussed the motor control mechanisms that underlie reflexive defense in hand-to-hand combat or that account for its temporal characteristics. This introductory study argues that the reflexive defense at the core of Krav Maga is a genuine reflex mediated at the brainstem level. The paper also discusses some aspects of reaction in the context of self-defense and combat sports, and the implications for the debate on whether Krav Maga training should involve more than one combat response to any given threat.

8

A Combined Sensorimotor Skill and Strength Training Program Improves Postural Steadiness in Rhythmic Sports Athletes

88%

Tsaklis P., Karlsson J., Grooten W., Äng B.

Human Movement

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2008

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vol. 9

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issue 1

34-40

EN

Purpose. The aim of this controlled trial was to evaluate the effects of a combined sensorimotor skill and strength training program on postural steadiness in junior females performing rhythmic sports gymnastics. Basic procedures. Twenty-six rhythmic sports athletes, aged 9 to 12 years, were randomized into one of two groups; a 6-week experimental group or to a control group, (during the 2004-2005 training period). In the experimental group, a sensorimotor and back-muscle-strengthening regime was added to the everyday training, while the control group continued with their ordinary training. Before and after the intervention, and at a 12-month follow, bipedal-stance center of foot pressure (CoP) sway area was examined with a statokinesigram indicating amplitude of vertical pressure fluctuations after stimulation of the vestibular system, and the distribution of body weight between legs. Main findings. At the 6-week follow-up, the experimental group had a larger decrement in CoP sway area (-59%, p = 0.004) and in asymmetrical body weight distribution (-58%, p < 0.001) compared to the control group (-0.1% and 2.3%, respectively), but not at the 12-month followup. Conclusions. The present sensorimotor skill and strength training program indicated short-term improved postural steadiness in rhythmic sports athletes. Exercises that specifically emphasize somatosensory and back strength aspects of training for postural steadiness may advantageously be integrated into their training routines.

9

Movements that are both variable and optimal

88%

Latash M. L.

Journal of Human Kinetics

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2012

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vol. 34

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issue 1

5-13

EN

This brief review addresses two major aspects of the neural control of multi-element systems. First, the principle of abundance suggests that the central nervous system unites elements into synergies (co-variation of elemental variables across trials quantified within the framework of the uncontrolled manifold hypothesis) that stabilize important performance variables. Second, a novel method, analytical inverse optimization, has been introduced to compute cost functions that define averaged across trials involvement of individual elements over a range of values of task-specific performance variables. The two aspects reflect two features of motor coordination: (1) using variable solutions that allow performing secondary tasks and stabilizing performance variables; and (2) selecting combinations of elemental variables that follow an optimization principle. We suggest that the conflict between the two approaches (a single solution vs. families of solutions) is apparent, not real. Natural motor variability may be due to using the same cost function across slightly different initial states; on the other hand, there may be variability in the cost function itself leading to variable solutions that are all optimal with respect to slightly different cost functions. The analysis of motor synergies has revealed specific changes associated with atypical development, healthy aging, neurological disorders, and practice. These have allowed formulating hypotheses on the neurophysiological mechanisms involved in the synergic control of actions.

10

The Effect of Immediate Verbal Feedback on the Efficiency and the Effectiveness of Swimming

88%

Zatoń K., Szczepan S.

Baltic Journal of Health and Physical Activity

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2012

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vol. 4

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issue 2

91-103

EN

Background: The aim of this study was to determine differences in stroke length and swimming time over a distance of 25m in a control and an experimental group from the provision of immediate verbal feedback.Material/Methods: The study involved 10 people practicing swimming. They were divided into an experimental and a control group. The subjects performed four trials, swimming the front crawl technique at the distance of 25 meters with a maximum speed. A specially designed research tool enabled the swimmers to obtain immediate verbal feedback during the test. In the control group no immediate verbal feedback was provided. In the experimental group the immediate verbal feedback was provided for the whole duration of swimming.Results: In the experimental group the average swimming stroke length with the front crawl technique has increased by 2.63% and the average swimming time decreased by 4.34% through the provision of immediate verbal feedback.Conclusions: In the experimental group, which obtained immediate verbal feedback, an increase in the average stroke length and a reduction in the average swimming time at the distance of 25m were observed.

11

Effect of Performance Speed on Trunk Movement Control During the Curl-Up Exercise

88%

Barbado D., Elvira J. L. L., Moreno F. J., Vera-Garcia F. J.

Journal of Human Kinetics

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2015

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vol. 46

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issue 1

29-37

EN

Trunk exercise speed has significant effects on neuro-mechanical demands; however, the influence of a variety of exercise speeds on motor control of the trunk displacement remains unknown. The aim of this study was to assess the effect of performance speed on trunk motion control during the curl-up exercise by analyzing the kinematic variance about the sagittal trajectory. Seventeen subjects volunteered to perform curl-ups at different cadences controlled by a metronome. Standard deviation (SD) and range (RG) of shoulder girdle medial-lateral displacement (SGML) and detrended fluctuation analysis (DFA) of SGML were calculated to examine linear variability and long range autocorrelation of medial-lateral upper trunk displacements, respectively. In addition, SD, RG and DFA of centre of pressure medial-lateral displacement (COPML) were performed to analyze the behavior of the motor system while controlling trunk displacement. Although SD and RG of COPML increased as speed increased, the curl-up cadence did not have significant effects on SD and RG of SGML. These results suggest that although high speed curl-ups challenged participants’ ability to carry out medial-lateral adjustments, an increase of performance speed did not modify the linear variability about the sagittal trajectory. Regarding DFA, the scaling exponent α of SGML and COPML was higher for the fastest movements, mainly in long term fluctuations. Therefore, to maintain the target trajectory, participants used different strategies depending on performance speed. This is to say, there were less trajectory changes when participants performed the fastest exercises.

12

Effects of workload level on muscle recruitment in cycling

88%

Priego J. I., Bini R. R., Lanferdini F. J., Carpes F. P.

Human Movement

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2014

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vol. 15

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issue 1

45-50

EN

Purpose. Despite the volume of studies addressing muscle activation during pedaling, it is unclear whether changes in workload level during cycling could dictate motor unit recruitment. The present study investigated the frequency content of lower limb muscle activation during submaximal workloads. Methods. Twelve male competitive cyclists pedaled at three workload levels: (1) maximum aerobic power output (POMAX), (2) first ventilatory threshold (POVT1), and (3) second ventilatory threshold (POVT2). Muscle activation was recorded from the right vastus medialis (VM), rectus femoris (RF), long head of biceps femoris (BF), tibialis anterior (TA), gastrocnemius medialis (GM), and soleus (SOL) muscles. Data from muscle activation were assessed using frequency band analysis. High and low frequencies and overall muscle activation were normalized to that collected at POMAX. Results. Greater overall activation was observed for VM (27%, p < 0.01, d = 1.22), RF (24%, p < 0.01, d = 0.96), BF (33%, p < 0.01, d = 1.43), GM (10%, p < 0.05, d = 0.91), and SOL (16%, p < 0.05, d = 0.81) at POVT2 than POVT1. No differences were observed in the high or low frequencies relative to overall muscle activation. Conclusions. Cyclists sustain changes at submaximal workloads via an equally distributed increase in muscle activation with no potential changes in motor unit recruitment.

13

Virtual Reality for Stroke Rehabilitation: assessment, training and the effect of virtual therapy

63%

Kiper P., Turolla A., Piron L., Agostini M., Baba A., Rossi S., Tonin P.

Medical Rehabilitation

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2010

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vol. 14(2)

23-32

PL

Upośledzenie funkcji ruchowych związanych z udarem mózgu ma w przypadku wielu chorych negatywny wpływ na samodzielność i na czynności Ŝycia codziennego i osoby te muszą być poddawane długotrwałej rehabilitacji. Liczne badania wykazały, że uczenie się nowych umiejętności motorycznych pobudza neuroplastyczność mózgu i w efekcie umożliwia poprawę funkcjonalną. W celu ułatwienia aktywacji obszarów mózgu, a w konsekwencji neuroplastyczności, korzystne może być łączenie tradycyjnej rehabilitacji ruchowej z innowacyjną technologią tak, aby poprzez wzmocniony trening promować ponowne uczenie się ruchu i ponowne nabywania umiejętności funkcjonalnych. W myśl tej zasady, wykorzystując adaptacyjne zdolności układu nerwowego, ćwiczenia powinny angażować wiele zmysłów i wymuszać aktywny udziału pacjenta. Trening ponownego uczenia się ruchu może być skuteczniejszy we wzbogaconym przez sprzężenie zwrotne środowisku koncentrując się na optymalizacji intrakcji osoby z komputerem między układem ruchu a fizycznym środowiskiem: technologia rzeczywistości wirtualnej dopuszcza możliwość utworzenia specjalnych ustawień, gdzie interakcja człowieka z komputerem jest zoptymalizowana. Wzmocnione sprzężenie zwrotne w środowisku wirtualnym (RFVE) może zawierać elementy potrzebne do maksymalizacji efektu uczenia się ruchu, np. praktyka powtarzających się i zróżnicowanych zadań, zastosowanie sprzężenia zwrotnego w odniesieniu do działania i efektu działania, oraz zwiększona motywacja. Zastosowanie RFVE może prowadzić do lepszych wyników w usprawnianiu niedowładnej kończyny górnej u pacjentów z udarem mózgu

EN

The motor function impairment deriving from stroke injury has a negative impact on autonomy and on the activities of daily living. Several studies have demonstrated that learning new motor skills is important to induce neuroplasticity and functional recovery. To facilitate the activation of brain areas and consequently neuroplasticity, it may be advantageous to combine traditional motor rehabilitation with innovative technology, in order to promote motor re-learning and skill re-acquisition by means of an enhanced training. Following these principles, exercises should involve multiple sensory modalities exploiting the adaptive nature of the nervous system, in order to promote active patient participation. Movement re-learning could be improved by means of training in an enriched environment focused on optimizing the affordances between the motor system and the physical environment: virtual reality technologies allow for the possibility to create specific settings where the affordances are optimized. Several autors report that patients treated in virtual representation could, in both acute and chronic stroke, improve their arm motor function. Reinforced Feedback in a Virtual Environment (RFVE), can incorporate the elements necessary to maximize motor learning, such as repetitive and differentiated task practice, feedback of performance and results, and reinforcement of the motivation. The RFVE approach may lead to better rehabilitation outcomes in the treatment of the upper limb in stroke patients.

14

Wpływ sauny fińskiej na koordynację sensomotoryczną u zdrowych mężczyzn

63%

Szafraniec R., Podgórska K., Walczak D.

Polish Journal of Sports Medicine

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2018

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vol. 34(2)

109-116

EN

Background. Sauna helps keep the organism in good physical and mental condition. It is a relaxing procedure, which alleviates the symptoms of fatigue, has a beneficial effect on the efficiency of the respiratory and circulatory systems, stimulates the immune system, increases the basal metabolic rate. This treatment, however, is a strong stimulus affecting the whole human organism but its effects on the nervous system and neural control of movement have not been sufficiently studied. The aim of the study was to answer the question whether sauna bathing impairs sensorimotor coordination. Material and methods. The study group consisted of 11 young men, aged 22-26 years. To assess sensorimotor coordination the feedback trial was performed on the force plate AccuSway (AMTI, USA). The following variables were analyzed: COP velocity (cm/s), COP path length (cm), hit time (s), overshoot (cm), reaction time (s). The sensorimotor coordination was evaluated three times: before sauna (T0), 20 minutes after sauna (T1), and 12 hours after sauna bathing (T2). Results. There were no statistically significant differences between the measurements T0, T1 and T2 in any of the analyzed variables. Conclusions. Finnish sauna bathing does not impair sensorimotor coordination in healthy men, both in the early and later time after its application.

PL

Wstęp. Sauna fińska wspomaga utrzymanie organizmu w dobrej kondycji fizycznej i psychicznej. Ma działanie relaksacyjne, niweluje symptomy zmęczenia, przyspiesza tempo podstawowej przemiany materii oraz wywiera pozytywny wpływ na układ oddechowy, krążenia i immunologiczny. Jest to zatem zabieg o silnym oddziaływaniu ogólnoustrojowym, chociaż jego wpływ na układ nerwowy oraz nerwową kontrolę ruchu nie został dostatecznie zbadany. Celem pracy była odpowiedź na pytanie czy jednorazowy zabieg w saunie fińskiej zaburza koordynację sensomotoryczną. Materiał i metody. Badana grupa składała się z 11 młodych mężczyzn w wieku 22-26 lat. Oceny koordynacji sensomotorycznej dokonano podczas testu feedback z użyciem platformy dynamograficznej AccuSway (AMTI, USA). Analizie poddano następujące zmienne: prędkość COP (cm/s), długość drogi COP (cm), czas trafienia (s), przestrzelenie (cm), czas reakcji (s). Koordynacja sensomotoryczna była oceniana trzykrotnie: przed sauną (T0), 20 minut po saunie (T1), 12 godzin po saunie (T2). Wyniki. Nie stwierdzono żadnych istotnych statystycznie różnic między kolejnymi pomiarami we wszystkich badanych zmiennych. Wnioski. Sauna fińska nie zaburza koordynacji sensomotorycznej u zdrowych mężczyzn, zarówno bezpośrednio po zabiegu, jak i w późniejszym czasie.

Refine search results

The influence of tactile feedback on hand movement accuracy

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

Groin Pain in Athletes – Clinical Experience

Practice effects on fast and accurate spatially constrained movements

Muscular Activation Patterns in Swimmers with Asymptomatic Shoulder Joint Instability

The Impact of Immediate Verbal Feedback on the Improvement of Swimming Technique

Motor Control Mechanisms and the Practice of Krav Maga - a Narrative Analysis

A Combined Sensorimotor Skill and Strength Training Program Improves Postural Steadiness in Rhythmic Sports Athletes

Movements that are both variable and optimal

The Effect of Immediate Verbal Feedback on the Efficiency and the Effectiveness of Swimming

Effect of Performance Speed on Trunk Movement Control During the Curl-Up Exercise

Effects of workload level on muscle recruitment in cycling

Virtual Reality for Stroke Rehabilitation: assessment, training and the effect of virtual therapy

Wpływ sauny fińskiej na koordynację sensomotoryczną u zdrowych mężczyzn