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1
Content available remote Relationship between Muscle Strength and Front Crawl Swimming Velocity
100%
EN
Purpose. competitive performance in swimming depends on a number of factors including, among others, the development of relevant muscle groups. The aim of the study was to clarify the relationship between muscle strength and swimming velocity and the role of individual muscle groups in front crawl swimming. Methods. sixteen physical education university students participated in the study. The strength values, defined as torque produced during isometric contractions, of eight upper and lower extremity muscle groups were measured. Data were compared with participants' front crawl swim times in the 25m and 50m distances. Results. correlation analysis demonstrated a relationship between muscle strength and swimming velocity. statistically significant relationships were observed between swimming velocity and the torque values of the elbow flexor and shoulder extensor muscles as well as the sum of upper extremity muscle torque values (p ⋋ 0.05). Conclusions. The results indicate the need for a focus on training those muscle groups identified as having a statistically significant relationship with swimming velocity for a given distance, as the sample showed deficiencies in the strength of those muscle groups responsible for generating propulsive force in the front crawl. Additionally, the collected data can serve as a diagnostic tool in evaluating the development of muscle groups critical for swimming performance.
PL
W pracy zaprezentowano możliwość wykorzystania inżynierskiego systemu pomiarowego MGC PLUS wraz z oprogramowaniem CATMAN do oceny wielkości momentów sił mięśniowych rozwijanych podczas ćwiczeń na przyrządzie typu wioślarz treningowy. W celu poprawy możliwości pomiarowych wykonano modernizację przyrządu, zaopatrując go w czujniki siły oraz przemieszczeń. Badaniom poddano 25 osób obojga płci, w wieku 20–24 lat, studentów inżynierii biomedycznej celem określenia przydatności przyrządu do monitorowania zmian charakterystyk mięśni.
EN
The paper presents the possibility of using the engineering measuring system MGC PLUS with software CATMAN for estimating the moments of muscle forces developed during exercises on the instrument type rowing training. In order to be able to upgrade the instrument of measurement was performed, providing him with force and displacement sensors. The study involved 25 people of both sexes, aged 20–24 years, biomedical engineering students to determine the suitability of the instrument to monitor changes of the muscle characteristics.
Human Movement
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2008
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tom 9
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nr 2
111-115
EN
Purpose. The aim of the study was to follow changes of the maximal muscle torque and maximal power output of lower extremities in male judoists during pre-competition training (PCT). The original hypothesis assumed that different training loads would cause changes of the maximal muscle torque and maximal power output of legs in male judoists during pre-competition training, but not changes of the topography of the maximal muscle torque in all muscle groups. Basic procedures. The study sample consisted of five male judoists from the Polish National Team. Muscle torque measurements in static conditions were performed shortly before PCT (I), after the strength training mesocycle (II) and immediately after PCT (III). Ten muscle groups were examined: flexors and extensors of the trunk, shoulder, elbow, hip and knee. The maximal power output of legs was measured on a dynamometric platform during counter-movement jumps (CMJ) and bounce counter-movement jumps (BCMJ). Main findings. The sums of the muscle torque of both arms and the trunk were changed insignificantly during pre-competition training (PCT). The sum of muscle torque of the right and left lower extremities increased significantly between the measurements I and III. The muscle percent topography of muscle groups also showed significant changes. Maximal power output of lower extremities measured during CMJ decreased significantly, but increased during BCMJ. Conclusion. PCT caused changes of the maximal muscle torque of lower extremities, but the muscle topography of the muscle groups revealed significant changes, too. The maximal power output of lower extremities measured during CMJ decreased.
4
Content available remote Isometric torque of arm abduction and adduction muscles in men
60%
PL
Przedmiotem pracy były pomiary statycznych momentów sił grup mięśni odwodzących i przywodzących ramię (w płasz-czyźnie czołowej). Badania wykonano na urządzeniu Biodex Medical System Pro 3 u 15 mężczyzn praworęcznych. Pomiary maksymalnych momentów sił w 5 wybranych pozycjach kątowych pomiędzy 0° (ramię wzdłuż tułowia) a 120° (dla obu kierunków) pozwoliły przebiegi moment-kąt opisać wielomianami drugiego stopnia. Przebieg momentu siły mięśni odwodzących ramię w funkcji kąta ma kształt hiperboli z maksimum przy kącie 0°, a dla mięśni przywodzących przyjmuje kształt paraboli z maksimum przy kącie 45°. Grupa mięśni odwodzących wyzwala większy moment siły od przywodzacych przy kącie 0° i 120°. W pozostałych, pośrednich, pozycjach kątowych jest niewielka przewaga mięśni przywodzą-cych nad odwodzącymi.
EN
The aim of work was to present the results of maximal (isometric) torque produced by muscles acting as arm abductors and adductors (frontal plane). The Biodex Medical System was applied to test the group of 15, right handed, young men. Torque was measured at 5 different angular positions between 0° (arm along the trunk) and 120° in both directions. The torque-angle curves were approximated with polynomial of the second order. The abduction torque-angle curve has a shape of hyperbola with maximum at 0° and adduction torque has a form of parabola with maximum at 45°. Abduction muscle group is stronger than adduction muscle group in the position of 0° and 120°. In the remaining positions the adduction muscle group is stronger than abduction muscle group.
EN
The professional literature widely describes research on measurements of force and torque flexors and extensors for upper limb muscles, but only a few publications talk about movements of the rotation muscles [4, 6]. Rotation movements of the forearm play an important role in the hand manipulating function [8]. The aim of the research is to define differences of muscles functions between healthy and ill upper limb. The group of 10 patients with the tennis elbow disease was examined [1,2,3], The results indicate changes in proportions of the movements on the side of the ill upper limb despite the dominating body side.
EN
The aim of this study was to determine the effects of two various types of power training on the muscle torques and power levels of lower extremities. During four weeks (five days a week) 27 students participated in this study. The training device consisted of an incline plane and a sliding seat. The varied types of power training were achieved by utilizing intermissions between the series of take offs. 4 series of 10 takes-offs with rest periods among series were carried out in A group (120s in length). Whereas the group B carried out the same number of take offs (40 take-offs) continuously. The interval training (group A) resulted in more effective dynamic values of the lower extremities than the continuous training adhered to by group B.
PL
W prezentowanej pracy dokonano porównania zawodników piłki siatkowej (n = 24) z siatkarzami plażowymi (n = 20), pod kątem osiąganych maksymalnych momentów sił mięśniowych, dla 10 zespołów mięśniowych. Badania przeprowadzono na specjalnych stanowiskach służących do pomiarów momentów sił w warunkach statyki. Badane grupy zawodników różniły się wysokością i masą ciała, jednak uzyskane wyniki pozwalają przypuszczać, iż zawodnicy obu dyscyplin charakteryzują się podobnymi wartościami względnej, maksymalnej siły mięśniowej i topografii momentów sił.
EN
This study presents a comparison of volleyball (n = 24) and beach volleyball (n = 20) players, in terms of maximal muscle torques for 10 muscle groups. The measurements were taken on a specific mechanical stands that were designed and built for measuring muscle torques under isometric conditions. Body mass and body height differed in examined groups significantly; however obtained results suggest, that players of both disciplines rather have similar level of relative muscle strength and a strength distribution.
EN
The aim of this study was to evaluate the potential correlation between asymmetry of lower limb muscle torque, asymmetry of vertical ground reaction force during take-off in young soccer players and their jumping abilities. Methods: Twenty-three young soccer player (16.9 ± 0.64 years old) participated in measurements. An isokinetic dynamometer, the Biodex System, was applied to test muscle torque (PT) of the knee flexors and extensors. The vertical ground reaction force (vGRF) was recorded from two Kistler plates. Jumping abilities were assessed with the horizontal (HJ) and vertical jump (VJ) tests. The asymmetry index (AI) was used to assess the asymmetry of the limbs. Results: The asymmetry index showed the highest asymmetry (over 10%) for the PT under static conditions for knee flexors and extensors. The correlation (–0.432, p = 0.038) was found between the asymmetry of vGRF and the height of the VJ. There was no correlation between the muscle torque and the height of the vertical jump. However, a correlation between the HJ length and muscle torque for flexors and extensors of the right and left lower limb was found. Conclusions: The asymmetry of the muscle torque of the flexors and extensors of the knee joint does not correlate with the results of both jumping ability tests. There was a statistically significant correlation between the vGRF asymmetry index during take-off and the height of the VJ. In the HJ, such a relationship was not found.
9
60%
EN
Isokinetic dynamometers are frequently used as training devices. They are also regularly employed to measure the characteristics of skeletal muscles under dynamic conditions. The combination of published data of such measurements and the authors’ own experience led to the present investigation of the validity of measurements performed using the Biodex System 3 dynamometer. Two individual dynamometers of the same type were used. A calibration technique was used to test the validity of measured torque and the angular coordinate of the position of the lever arm of the dynamometer under static conditions. The results of measurements performed under dynamic (isokinetic) conditions were verified by comparing numerical values of tests provided in the Biodex report and raw data collected directly from the measuring computer of the same isokinetic machine. The shapes of experimentally determined characteristics of torque Mmax(ů) and power P(ů) were also analysed, taking into consideration their conformity with the laws of thermodynamics and known properties of skeletal muscles. The static tests showed that the indications of the Biodex System 3 dynamometer lay within the error range specified by the manufacturer. Therefore, the results of static measurements can be considered accurate. According to the isokinetic tests, the values of angular velocity were also accurate. However, indications of torque and power were much less accurate, justifying the uncertainty over whether they can be considered true results of measurement.
PL
Niniejsza praca składa się z dwóch zasadniczych części. W pierwszej zaprezentowano wyniki identyfikacji momentów sił mięśniowych w warunkach izokinetycznych uzyskane za pomocą urządzenia BIODEX SYSTEM 3. Analizie poddano wybrane stawy człowieka. Pomiary przeprowadzono dla różnych prędkości kątowych i dla różnych zakresów ruchu w stawach. W drugiej części pracy przedstawiono trójwymiarowy model kończyny dolnej. Główny nacisk w procesie modelowania położono na wyznaczanie dystrybucji sił mięśniowych na poszczególne mięśnie obsługujące badany staw. Wykorzystano w tym celu metodę "pseudoodwrócenia" macierzy dystrybucji tych momentów.
EN
The paper is divided into two basic parts. The results of identification of net artificial torques have been presented in the first part of the paper. Isometric testing was done with the use of the BIODEX SYSTEM 3 equipment. The selected joints of human being were examined. The angular velocities and the joint's range of motion were successively changed while testing. The second part of the paper deals with 3D modelling of the lower extremity of a human being. The main goal of the modelling process was focused on distributing the net artificial torques for individual muscles. In order to achieve it, the authors used the pseudoinverse method.
PL
Celem pracy jest przedstawienie analizy błędów oraz wyników symulacji wartości momentów sił w stawie skokowym dla płaskiego modelu kończyny dolnej, wynikających z różnego przebiegu środka parcia stopy na podłoże (CoP - center of pressure). Składowa przednio-tylna CoP była przesuwana o wektory [a;b], gdzie a i b - dowolne liczby rzeczywiste. Wartości uzyskane dla symulacji wskazują, że zmiana położenia CoP może generować bardzo duże błędy w wartościach momentów. Jak wynika z symulacji dla badanego modelu zmiana położenia CoP o wektor np. [0;7] cm, generuje krzywą tożsamą z trajektorią przebiegu momentów w stawie skokowym w chodzie charakterystycznym dla osoby niepełnosprawnej.
EN
The purpose of this study was to investigate the effect of errors in the center of pressure (CoP) locations on two dimensional lower limb joint moment during gait. Kinematics and kinetic data were synchronized in MatLab. Antero - posterior component of CoP was shifted by vectors [a;b], where a and b -real numbers. The study shows that change of the location of CoP can generate very large mistakes in calculation of joint moments. As results from simulation for studied model the change of CoP about the vector e.g. [0;7]cm, generate the curve the same like for the handicap person.
12
Content available remote Estimation of muscle torque in various combat sports
51%
EN
The purpose of the research was to compare muscle torque of elite combat groups. Twelve taekwondo WTF athletes, twelve taekwondo ITF athletes and nine boxers participated in the study. Measurements of muscle torques were done under static conditions on a special stand which belonged to the Department of Biomechanics. The sum of muscle torque of lower right and left extremities of relative values was significantly higher for taekwondo WTF athletes than for boxers (16%% p < 0.001 for right and 10%, p < 0.05 for left extremities) and taekwondo ITF (10%, p < 0.05 for right and 8% for left extremities). Taekwondo ITF athletes attained significantly higher absolute muscle torque values than boxers for elbow flexors (20%, p < 0.05 for right and 11% for left extremities) and extensors (14% for right and 18%, p < 0.05 for left extremities) and shoulder flexors (10% for right and 12%, p < 0.05 for left extremities) and extensors (11% for right and 1% for left extremities). Taekwondo WTF and taekwondo ITF athletes obtained significantly different relative values of muscle torque of the hip flexors (16%, p < 0.05) and extensors (11%, p < 0.05) of the right extremities.
EN
The paper presents a general approach of modeling the human upper limb dynamics accordingly to the multibody system dynamics. The two-dimensional model of the limb is presented. Three generalized coordinates, in the form of intersegmental angles, describe the motion of the limb. Analysis of upper limb motion is based on inverse dynamics. Algorithm of numerical calculations enables to estimate the resultant moments of muscular forces in joints. A FORTRAN program for planar dynamics of upper limb motion was created.
PL
Celem pracy jest opracowanie modelu dynamicznego kończyny górnej w oparciu o dynamikę układów wieloczłonowych. W pracy prezentowany jest płaski model kończyny górnej składający się z trzech ciał sztywnych ramię, przedramię i dłoń połączonych w łańcuch biokinematyczny z nieruchomym członem modelującym tułów. Poszczególne segmenty modelu połączone są ze sobą za pomocą obrotowych par kinematycznych. Ruch kończyny został opisany za pomocą trzech współrzędnych uogólnionych w postaci kątów pomiędzy poszczególnymi segmentami. W analizie ruchu wykorzystano odwrotne zadanie dynamiki. Algorytm obliczeń numerycznych pozwala na wyznaczenie wypadkowych momentów sił mięśniowych działających na poszczególne stawy kończyn. W oparciu o przedstawioną metodykę badań modelowych został opracowany komputerowy program pozwalający na wykonanie obliczeń napisany w języku FORTRAN.
PL
W pracy dokonano identyfikacji obciążeń wewnętrznych w wybranych stawach w trakcie kontaktu skoczka z podłożem podczas wykonywania przerzutu i salta w przód w pozycji łamanej. Przedmiotem analizy były czasowe charakterystyki zbiorczych momentów sił mięśniowych i reakcji w stawach skokowym, kolanowym, biodrowym oraz ramiennym. Obliczenia wykonano na podstawie trójwymiarowego modelu ciała człowieka zdefiniowanego we współrzędnych naturalnych. Czasowe charakterystyki obciążeń wewnętrznych w stawach otrzymano wskutek rozwiązania zagadnienia odwrotnego. Zbadano również wpływ zmieniającej się długości członów modelu biomechanicznego na rezultaty identyfikacji. Wyniki obliczeń pozwoliły na zidentyfikowanie trójwymiarowego stanu obciążeń w stawach oraz potwierdziły przydatność współrzędnych naturalnych w modelowaniu układów biomechanicznych.
EN
The internal loads at the selected joints during contact of the jumper with the ground when performing the handspring front pike somersault were identified in this work. The computations were based on a three-dimensional model of the human body defined in natural coordinates. The time courses of the net muscle torques and internal reactions at the hip, knee, ankle and shoulder joints were obtained by inverse dynamics. The influence of nonconsistent lengths of anatomical segments on the computation results was also verified. The achieved results revealed 3D state of internal loads at the joints. Itwas also shown that the natural coordinates provide a useful environment for modeling spatial biomechanical structures.
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