The handspring front somersault in pike position is analyzed in this paper. The computations have... more The handspring front somersault in pike position is analyzed in this paper. The computations have been based on a threedimensional model of the human body defined in natural coordinates. The time histories of net muscle torques and internal reactions at the ankle, knee, hip and upper trunk-neck joints have been obtained after the solution of the inverse dynamics problem. The sagittal, frontal and transverse plane components of selected net muscle torques and internal reactions are presented and discussed in the paper. It has also been demonstrated that natural coordinates provide a useful framework for modelling spatial biomechanical structures.
Summary The internal loads at the selected joints during contact of the jumper with the ground wh... more Summary 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. It was also shown that the natural coordinates provide a useful environment for modeling spatial biomechanical structures.
The Journal of sports medicine and physical fitness, 2012
AIM The purpose of this study was to examine how focusing attention during nine weeks of plyometr... more AIM The purpose of this study was to examine how focusing attention during nine weeks of plyometric training influence jumping performance. It was hypothesized that participants utilizing an external focus of attention during practice would produce greater improvements in jumping behavior compared to participants practicing in the internal and control conditions. METHODS Thirty-six untrained but physically active male college students were randomly assigned to 1 of 3 plyometric groups with a different focus of attention: external (EXF; N.=12), internal (INF; N.=12), and control (CON; N.=12). All participants subsequently participated in the same an 9-week periodized training program. Standing long jump (SLJ), countermovement jump (CMJ) and drop jump (DJ) were tested pre- and posttraining intervention. RESULTS The EXF group exhibited greater improvement (P<0.05) in jumping distance for SLJ and height for CMJ than both the INF and CON groups, while the enhancement in jumping height...
Streszczenie angielskie: Identification and an inverse dynamic parametric optimization method for... more Streszczenie angielskie: Identification and an inverse dynamic parametric optimization method for solving optimal control problems involving planar biomechanical linkages is presented. The method is applied to minimize the performance time of a mae-geri kick. Parameterized generalized velocities as design variables and sequential quadratic programming (SQP) method were used in the computations. The actual and optimal time characteristics of the net torques at the basic joints of a leg and actual internal reactions in ...
Streszczenie angielskie: The paper deals with the biomechanical identification of two taekwon-do ... more Streszczenie angielskie: The paper deals with the biomechanical identification of two taekwon-do kicks: ap chagi and bandae dollyo chagi. Two ranked 1 dan taekwon-do athletes took part in the research. The research was conducted by use of the Boxing Training Simulator (BTS) and the APAS system. The time characteristics of the forces exerted when performing the kicks, the time characteristics of the net torques at the basic joints of a leg (ap chagi), and the time histories of selected kinematic parameters (bandae ...
International Journal of Environmental Research and Public Health
Background: The Laser Run combined event is part of the modern pentathlon, consisting of successi... more Background: The Laser Run combined event is part of the modern pentathlon, consisting of successive shooting and running phases. The main factor hindering accurate and fast shooting is the increasing fatigue caused by running effort. The aim of this study was to assess the impact of the running phases on the postural balance in the shooting position of pentathletes in a Laser Run event. Methods: 25 modern pentathletes (18.6 ± 1.7 years), members of the Polish Association of Modern Pentathlon, completed a Laser Run event. During each shooting series, a Zebris dynamometric platform recorded the displacement of the centre of pressure (COP). Results: Significant changes in the average velocity of the COP (F = 3.43; p = 0.0223) and the width of the ellipse of the COP shifts area WoE (F = 3.30; p = 0.0259) between the first and the second shooting series were observed. The average velocity of the COP in series I was 72.6 m/s and increased to 84.3 m/s in series II. In turn, the average wid...
Background The study aimed to assess whether intermittent pneumatic compression (IPC) and intermi... more Background The study aimed to assess whether intermittent pneumatic compression (IPC) and intermittent negative pressure (INP) would attenuate the muscle damaging effects of eccentric exercise. Methods Forty-five healthy males were recruited. Immediately post, 24 and 48 h post eccentric exercise consisting of 100 drop jumps, volunteers randomly received 30-min sessions of intermittent pneumatic compression (IPC, n = 15) or intermittent negative pressure (INP, n = 15), or sham microcurrent (PT, n = 15). Creatine kinase (CK), lactate dehydrogenase (LDH), isokinetic muscle strength, soreness and active flexion of the knee joint were measured after every therapy session. Results No significant intergroup differences were observed in biochemical or functional measurements. However, there was an increase in muscle soreness (P
Introduction. Neuromuscular electrical stimulation is applied in muscle atrophy and in muscle str... more Introduction. Neuromuscular electrical stimulation is applied in muscle atrophy and in muscle strength and endurance training in athletes. Muscle soreness and temporary reduction in muscle strength may occur as adverse effects. Laser therapy has been used as a method of counteracting delayed onset muscle soreness following volitional exercise, but not following electrical stimulation. The aim of the study was to determine whether low-level laser therapy applied prior to electrical stimulation accelerates the recovery of muscle strength and decreases the duration and intensity of muscle soreness at rest after intensive isometric neuromuscular electrical stimulation of the quadriceps femoris muscle. Material and methods. A randomised crossover trial was carried out on 24 healthy, recreationally active men aged 22-24 years. Low-level laser therapy or sham laser therapy was applied prior to a single session of neuromuscular electrical stimulation of the quadriceps femoris muscle with ty...
Background Low level laser therapy (LLLT) is among novel methods for preventing and treating musc... more Background Low level laser therapy (LLLT) is among novel methods for preventing and treating muscle damage and soreness induced by volitional exercise, but little is known about using LLLT before neuromuscular electrical stimulation. The aim of this first randomised, double blind, crossover trial addressing this issue was to evaluate effects of LLLT on muscle damage and oxidative stress, as well as recovery of muscle function after a single session of isometric neuromuscular electrical stimulation(NMES). Methods Twenty four moderately active, healthy men aged 21–22 years received 45 electrically evoked tetanic, isometric contractions of the quadriceps femoris, preceded by LLLT or sham-LLLT. Maximal isometric voluntary muscle torques, perceived soreness, and blood samples were analysed from baseline to 96 h post intervention. We measured plasma markers of muscle damage (the activity of creatine kinase), and inflammation (C-reactive protein), and evaluated redox state parameters. Resu...
International Journal of Environmental Research and Public Health
Postural balance is a key element of shooting effectiveness, which determines the outcome of mode... more Postural balance is a key element of shooting effectiveness, which determines the outcome of modern pentathlon competitions. The aim of the study is to examine the postural balance of 27 pentathletes (12 females and 15 males; mean age: 18.0 ± 1.8 years), and 26 physically active, untrained subjects (12 females and 14 males; mean age: 22.5 ± 1.4 years), and to investigate the impact of footwear on the stability of the shooting position in pentathletes. Methods: Static postural balance was examined during quiet stance in four test conditions (standing in footwear with eyes opened, standing in footwear with eyes closed, standing barefoot with eyes opened, and standing barefoot with eyes closed). During each postural balance measurement, the participant remained still on the platform, with their arms in front of their body. Postural balance in the shooting position was only evaluated in the group of pentathletes. The athlete was asked to assume a comfortable shooting position on the pla...
Streszczenie. W pracy dokonano identyfikacji ciosu maeYgeri i przedstawiono optymalne charakterys... more Streszczenie. W pracy dokonano identyfikacji ciosu maeYgeri i przedstawiono optymalne charakterystyki sterujące modelu biomechanicznego uzyskane za pomocą optymalizacji parametrycznej. Parametryzacji zostały poddane prędkości uogόlnione modelu. Ich wartości początkowe obliczono na podstawie analizy kinematycznej zapisu video badanego ciosu. Za kryterium optymalizacyjne wybrano minimalny czas zadawania ciosu. Warunki brzegowe odpowiadały zarejestrowanej początkowej i końcowej konfiguracji kończyny. W ...
Introduction. The aim of the study was to determine the torque of the knee extensors and flexors ... more Introduction. The aim of the study was to determine the torque of the knee extensors and flexors of the lead lower limb, the torque of the shoulder extensors and flexors of the dominant upper limb, and the torque generated by the muscles of the kinematic chain going from the trail lower limb to the hand of the dominant limb in male handball players during the annual training macrocycle. Changes in jump height and throwing velocity were also investigated. Material and methods. The study involved 13 handball players from a Polish second-league team. The measurements were performed four times: at the beginning of the preparation period, at the beginning of the season, at the end of the first part of the season, and at the end of the second part of the season. Torque was measured in isokinetic and isometric conditions. Jumping ability was tested using a piezoelectric platform, and throwing velocity was measured with a speed radar gun. Results. The study found statistically significant d...
Abstract In the article comparison of time-frequency spectra of EMG signals obtained by the follo... more Abstract In the article comparison of time-frequency spectra of EMG signals obtained by the following methods: Fast Fourier Transform, predictive analysis and wavelet analysis is presented. The EMG spectra of biceps and triceps while an adult man was flexing his arm were analysed. The advantages of the predictive analysis were shown as far as averaging of the spectra and determining the main maxima are concerned. The Continuous Wavelet Transform method was applied, which allows for the proper distribution of the scales, ...
The primary criterion of running speed is the time necessary to travel a designated distance. So ... more The primary criterion of running speed is the time necessary to travel a designated distance. So far, the accuracy and reliability of measurement of kinematic parameters of running was mainly assessed based on speed tests involving the phase of acceleration. However, there are no data on accuracy and reliability of running speed tests involving running starts (preceded by a pre-run), during which the speed is relatively constant. The purpose of this study was to determine the accuracy and reliability of measurements of kinematic parameters in running speed test (20 m + 20 m). The research involved participation of female students (n=16) of the university of physical education, who were not involved in competitive sports. The average age of the participants was 20.89±0.6 years, body height 169.4±5.2 cm and weight 61.3±6.4 kg. The 20 m + 20 m speed test involved running (in as short time as possible) of a 20 m distance from a 20 m running start. The participants performed two runs dur...
This study presents an inverse dynamic parametric optimization method for solving optimal control... more This study presents an inverse dynamic parametric optimization method for solving optimal control problems involving planar biomechanical linkages. Two biomechanical models of the human lower leg have been defined in generalized and natural coordinates to validate the method in different modeling conditions. Both models are composed of three anatomical segments representing the thigh, shank and foot. The configuration of the models is described by five generalized, and eight natural coordinates. After solving the inverse dynamic problem, a parametric optimization was applied to find the optimal control. The optimization criterion was to minimize the performance time of a karate kick. The velocities were chosen as state variables. The starting and final configuration of the leg, which formed the boundary conditions of the movement, were in accordance with video recordings. A sequential quadratic programming method (SQP) was used in the computations. The optimal time characteristics o...
The handspring front somersault in pike position is analyzed in this paper. The computations have... more The handspring front somersault in pike position is analyzed in this paper. The computations have been based on a threedimensional model of the human body defined in natural coordinates. The time histories of net muscle torques and internal reactions at the ankle, knee, hip and upper trunk-neck joints have been obtained after the solution of the inverse dynamics problem. The sagittal, frontal and transverse plane components of selected net muscle torques and internal reactions are presented and discussed in the paper. It has also been demonstrated that natural coordinates provide a useful framework for modelling spatial biomechanical structures.
Summary The internal loads at the selected joints during contact of the jumper with the ground wh... more Summary 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. It was also shown that the natural coordinates provide a useful environment for modeling spatial biomechanical structures.
The Journal of sports medicine and physical fitness, 2012
AIM The purpose of this study was to examine how focusing attention during nine weeks of plyometr... more AIM The purpose of this study was to examine how focusing attention during nine weeks of plyometric training influence jumping performance. It was hypothesized that participants utilizing an external focus of attention during practice would produce greater improvements in jumping behavior compared to participants practicing in the internal and control conditions. METHODS Thirty-six untrained but physically active male college students were randomly assigned to 1 of 3 plyometric groups with a different focus of attention: external (EXF; N.=12), internal (INF; N.=12), and control (CON; N.=12). All participants subsequently participated in the same an 9-week periodized training program. Standing long jump (SLJ), countermovement jump (CMJ) and drop jump (DJ) were tested pre- and posttraining intervention. RESULTS The EXF group exhibited greater improvement (P<0.05) in jumping distance for SLJ and height for CMJ than both the INF and CON groups, while the enhancement in jumping height...
Streszczenie angielskie: Identification and an inverse dynamic parametric optimization method for... more Streszczenie angielskie: Identification and an inverse dynamic parametric optimization method for solving optimal control problems involving planar biomechanical linkages is presented. The method is applied to minimize the performance time of a mae-geri kick. Parameterized generalized velocities as design variables and sequential quadratic programming (SQP) method were used in the computations. The actual and optimal time characteristics of the net torques at the basic joints of a leg and actual internal reactions in ...
Streszczenie angielskie: The paper deals with the biomechanical identification of two taekwon-do ... more Streszczenie angielskie: The paper deals with the biomechanical identification of two taekwon-do kicks: ap chagi and bandae dollyo chagi. Two ranked 1 dan taekwon-do athletes took part in the research. The research was conducted by use of the Boxing Training Simulator (BTS) and the APAS system. The time characteristics of the forces exerted when performing the kicks, the time characteristics of the net torques at the basic joints of a leg (ap chagi), and the time histories of selected kinematic parameters (bandae ...
International Journal of Environmental Research and Public Health
Background: The Laser Run combined event is part of the modern pentathlon, consisting of successi... more Background: The Laser Run combined event is part of the modern pentathlon, consisting of successive shooting and running phases. The main factor hindering accurate and fast shooting is the increasing fatigue caused by running effort. The aim of this study was to assess the impact of the running phases on the postural balance in the shooting position of pentathletes in a Laser Run event. Methods: 25 modern pentathletes (18.6 ± 1.7 years), members of the Polish Association of Modern Pentathlon, completed a Laser Run event. During each shooting series, a Zebris dynamometric platform recorded the displacement of the centre of pressure (COP). Results: Significant changes in the average velocity of the COP (F = 3.43; p = 0.0223) and the width of the ellipse of the COP shifts area WoE (F = 3.30; p = 0.0259) between the first and the second shooting series were observed. The average velocity of the COP in series I was 72.6 m/s and increased to 84.3 m/s in series II. In turn, the average wid...
Background The study aimed to assess whether intermittent pneumatic compression (IPC) and intermi... more Background The study aimed to assess whether intermittent pneumatic compression (IPC) and intermittent negative pressure (INP) would attenuate the muscle damaging effects of eccentric exercise. Methods Forty-five healthy males were recruited. Immediately post, 24 and 48 h post eccentric exercise consisting of 100 drop jumps, volunteers randomly received 30-min sessions of intermittent pneumatic compression (IPC, n = 15) or intermittent negative pressure (INP, n = 15), or sham microcurrent (PT, n = 15). Creatine kinase (CK), lactate dehydrogenase (LDH), isokinetic muscle strength, soreness and active flexion of the knee joint were measured after every therapy session. Results No significant intergroup differences were observed in biochemical or functional measurements. However, there was an increase in muscle soreness (P
Introduction. Neuromuscular electrical stimulation is applied in muscle atrophy and in muscle str... more Introduction. Neuromuscular electrical stimulation is applied in muscle atrophy and in muscle strength and endurance training in athletes. Muscle soreness and temporary reduction in muscle strength may occur as adverse effects. Laser therapy has been used as a method of counteracting delayed onset muscle soreness following volitional exercise, but not following electrical stimulation. The aim of the study was to determine whether low-level laser therapy applied prior to electrical stimulation accelerates the recovery of muscle strength and decreases the duration and intensity of muscle soreness at rest after intensive isometric neuromuscular electrical stimulation of the quadriceps femoris muscle. Material and methods. A randomised crossover trial was carried out on 24 healthy, recreationally active men aged 22-24 years. Low-level laser therapy or sham laser therapy was applied prior to a single session of neuromuscular electrical stimulation of the quadriceps femoris muscle with ty...
Background Low level laser therapy (LLLT) is among novel methods for preventing and treating musc... more Background Low level laser therapy (LLLT) is among novel methods for preventing and treating muscle damage and soreness induced by volitional exercise, but little is known about using LLLT before neuromuscular electrical stimulation. The aim of this first randomised, double blind, crossover trial addressing this issue was to evaluate effects of LLLT on muscle damage and oxidative stress, as well as recovery of muscle function after a single session of isometric neuromuscular electrical stimulation(NMES). Methods Twenty four moderately active, healthy men aged 21–22 years received 45 electrically evoked tetanic, isometric contractions of the quadriceps femoris, preceded by LLLT or sham-LLLT. Maximal isometric voluntary muscle torques, perceived soreness, and blood samples were analysed from baseline to 96 h post intervention. We measured plasma markers of muscle damage (the activity of creatine kinase), and inflammation (C-reactive protein), and evaluated redox state parameters. Resu...
International Journal of Environmental Research and Public Health
Postural balance is a key element of shooting effectiveness, which determines the outcome of mode... more Postural balance is a key element of shooting effectiveness, which determines the outcome of modern pentathlon competitions. The aim of the study is to examine the postural balance of 27 pentathletes (12 females and 15 males; mean age: 18.0 ± 1.8 years), and 26 physically active, untrained subjects (12 females and 14 males; mean age: 22.5 ± 1.4 years), and to investigate the impact of footwear on the stability of the shooting position in pentathletes. Methods: Static postural balance was examined during quiet stance in four test conditions (standing in footwear with eyes opened, standing in footwear with eyes closed, standing barefoot with eyes opened, and standing barefoot with eyes closed). During each postural balance measurement, the participant remained still on the platform, with their arms in front of their body. Postural balance in the shooting position was only evaluated in the group of pentathletes. The athlete was asked to assume a comfortable shooting position on the pla...
Streszczenie. W pracy dokonano identyfikacji ciosu maeYgeri i przedstawiono optymalne charakterys... more Streszczenie. W pracy dokonano identyfikacji ciosu maeYgeri i przedstawiono optymalne charakterystyki sterujące modelu biomechanicznego uzyskane za pomocą optymalizacji parametrycznej. Parametryzacji zostały poddane prędkości uogόlnione modelu. Ich wartości początkowe obliczono na podstawie analizy kinematycznej zapisu video badanego ciosu. Za kryterium optymalizacyjne wybrano minimalny czas zadawania ciosu. Warunki brzegowe odpowiadały zarejestrowanej początkowej i końcowej konfiguracji kończyny. W ...
Introduction. The aim of the study was to determine the torque of the knee extensors and flexors ... more Introduction. The aim of the study was to determine the torque of the knee extensors and flexors of the lead lower limb, the torque of the shoulder extensors and flexors of the dominant upper limb, and the torque generated by the muscles of the kinematic chain going from the trail lower limb to the hand of the dominant limb in male handball players during the annual training macrocycle. Changes in jump height and throwing velocity were also investigated. Material and methods. The study involved 13 handball players from a Polish second-league team. The measurements were performed four times: at the beginning of the preparation period, at the beginning of the season, at the end of the first part of the season, and at the end of the second part of the season. Torque was measured in isokinetic and isometric conditions. Jumping ability was tested using a piezoelectric platform, and throwing velocity was measured with a speed radar gun. Results. The study found statistically significant d...
Abstract In the article comparison of time-frequency spectra of EMG signals obtained by the follo... more Abstract In the article comparison of time-frequency spectra of EMG signals obtained by the following methods: Fast Fourier Transform, predictive analysis and wavelet analysis is presented. The EMG spectra of biceps and triceps while an adult man was flexing his arm were analysed. The advantages of the predictive analysis were shown as far as averaging of the spectra and determining the main maxima are concerned. The Continuous Wavelet Transform method was applied, which allows for the proper distribution of the scales, ...
The primary criterion of running speed is the time necessary to travel a designated distance. So ... more The primary criterion of running speed is the time necessary to travel a designated distance. So far, the accuracy and reliability of measurement of kinematic parameters of running was mainly assessed based on speed tests involving the phase of acceleration. However, there are no data on accuracy and reliability of running speed tests involving running starts (preceded by a pre-run), during which the speed is relatively constant. The purpose of this study was to determine the accuracy and reliability of measurements of kinematic parameters in running speed test (20 m + 20 m). The research involved participation of female students (n=16) of the university of physical education, who were not involved in competitive sports. The average age of the participants was 20.89±0.6 years, body height 169.4±5.2 cm and weight 61.3±6.4 kg. The 20 m + 20 m speed test involved running (in as short time as possible) of a 20 m distance from a 20 m running start. The participants performed two runs dur...
This study presents an inverse dynamic parametric optimization method for solving optimal control... more This study presents an inverse dynamic parametric optimization method for solving optimal control problems involving planar biomechanical linkages. Two biomechanical models of the human lower leg have been defined in generalized and natural coordinates to validate the method in different modeling conditions. Both models are composed of three anatomical segments representing the thigh, shank and foot. The configuration of the models is described by five generalized, and eight natural coordinates. After solving the inverse dynamic problem, a parametric optimization was applied to find the optimal control. The optimization criterion was to minimize the performance time of a karate kick. The velocities were chosen as state variables. The starting and final configuration of the leg, which formed the boundary conditions of the movement, were in accordance with video recordings. A sequential quadratic programming method (SQP) was used in the computations. The optimal time characteristics o...
Uploads
Papers