Kostas Gianikellis - Academia.edu (original) (raw)

Papers by Kostas Gianikellis

ISBS - Conference Proceedings Archive, Mar 18, 2009

SONIC DIGITIZING is a new and very precise method for kinematic analysis In shooting sports (Gian... more SONIC DIGITIZING is a new and very precise method for kinematic analysis In shooting sports (Gianikellis et al. 1992). The purpose of this study was to Improve the technical characteristics and capabilities of this method, also its applicability for complete Biomechanical Analysis in movements of high precision and shooting sports Now, the sampling rate 1s 66 6 Hz (Instead of the 37 Hz previously obtained frequency) divided by the number of emitters placed in an active volume of a cube with two meters side length. The Sonic Digitizer would be optionally faster working In smaller volumes (up to 100 Hz) In this way, we can use more ultrasound emitters sampling them within an appropriate rate for this class of motor patterns (according to Shannon s theorem). Also, the 3-d~mens~onaclo ordinates of the emitters are calculated respect to the system of reference by means of a Newton-Raphson's optimization algorithm This algorithm improves the precision of the system The calculated stan...

INTRODUCTION "Muscle strength is defined as the magnitude of the torque exerted by a muscle ... more INTRODUCTION "Muscle strength is defined as the magnitude of the torque exerted by a muscle (or muscles) in a single maximal isometric contraction of unrestricted duration" (Atha, 1981 ). Strength diagnosis (Schmidtbleicher, 1992) by means of strength and power tests is considered as a very useful procedure to identify talents or to control the evolution in the tralning or rehabilitation progress. The results of specific tests provide information about relative deficiencies and they can be used to figure out individual strength training programs. Also, maximum isometric force and the rate of force development seem to be important qualities related to the athletic performance (Wilson and Murphy, 1995). In consequence of this study a strain-gauge uniaxial load cell has been designed and developed to measure in real-time, and store the well established mechanical parameters to evaluate muscular force during isometric exercise. These parameters are: a) the peak value of the fo...

The purpose of this study is to analyze the individual rifle-shooting sport technique of an inter... more The purpose of this study is to analyze the individual rifle-shooting sport technique of an international level shooter defining the factors of mechanical instability that have negative effects on the performance. Kinematic and stabilometric data were registered by means of a sonic digitiser synchronised with a force platform. Postural stability has been evaluated for ten intervals of the last five seconds of the aiming time. Multivariate analysis techniques allowed to identify two factors of 'postural instability' that explain the 78.8% of the total variability. Namely, 'instability of the segment pelvis during the 7th interval of the aiming time' and 'instability of the structure that form the rifle and the supporting it upper trunk during the final second of the aiming line'. The results provide objective information respect to the motor patterns in the rifle-shooting justifying the proposed theoretical model for the identification of the postural stabilit...

INTRODUCTION It is well known that physically handicapped persons can participate in many sport m... more INTRODUCTION It is well known that physically handicapped persons can participate in many sport modalities. However, the disability of blind people is not compatible with shooting drills or archery. Our endeavor in this study is to establish the theoretical frame for the development of system that is able to generate in real time acoustical signals (feedback information) making possible the practice of shooting sports by persons with this kind of disability. To this purpose we use sonic digitizing to convert information respect to three-dimensional coordinates of ultrasound emitters to digital values, based on the properties of sound propagation. The measurement chain consists in a SAC Sonic Digitizer (GP8-3D) that communicates with a personal computer via a parallel interface (PI012), for higher data rate throughput, and a synchronized microphone sensor to detect the instant of triggering. The sampling rate of the sonic digitizer is 66.6 Hz divided by the number (k=3) of sound emit...


European Journal of Human Movement, 2010

The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neuroge... more The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neurogenics (stretch reflex), myogenics (viscoelasticity of the musculo-tendinous structures) and joint constraints. The main purpose of this study was to determine the intervention of the muscles quadriceps femoris (rectus femoris - vastus medialis) and biceps femoris and its relationship with the kinematics of the hip joint during a common ballistic stretching exercise. Kinematic data of the hip joint and EMGraphic data of the muscles quadriceps femoris (rectus femoris -vastus medialis) and biceps femoris were recorded by a measurement chain which consists of an EMG synchronized with an ELGoniometric system. The study yielded information concerning the sequence of muscular activation and the history of the angular velocity and acceleration of the hip joint during the defined phases of acceleration and deceleration of the flexion-extension movements. The obtained results confirmed statisticall...

Biomecánica

El análisis biomecánico del movimiento humano tiene aplicaciones, en el ámbito médico, ocupaciona... more El análisis biomecánico del movimiento humano tiene aplicaciones, en el ámbito médico, ocupacional y deportivo analizando la técnica y diseñando material deportivo de altas prestaciones. El objetivo de este trabajo ha sido presentar el software desarrollado en el Laboratorio de Biomecánica del Movimiento Humano y de Ergonomía de la Facultad de Ciencias del Deporte de la Universidad de Extremadura que permite analizar el movimiento humano normal y patológico. El paquete BiomSoft desarrollado en entorno MATLAB 5.3 permite el tratamiento y la representación de los datos procedentes del análisis biomecánico aplicando diferentes técnicas de suavizado e interpolación de los datos cinemáticos y cálculo de las magnitudes cinemáticas lineales y angulares, la creación y uso de una base de datos de parámetros inerciales, análisis dinámico inverso y determinación de los momentos musculares netos y del trabajo mecánico realizado, análisis espectral de los datos Electromiográficos y de Estabilome...

The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neuroge... more The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neurogenic (stretch reflex), myogenic (viscoeiasticity of the musculo-tendinous structures) and joint constraints (Taylor et al. 1990; 1997). Among the other common techniques (passive, static and PNF) ballistic stretching is using the momentum of a moving body or a limb to force it beyond its normal range of motion. However, in spite of the exciting concerns of stretching neuromechanics, as well as, the overestimation of the role of connective tissue and the underestimation of the resistance of the muscles to stretch (Hutton, 1992), there is a lack of studies concerning the muscular activity in ballistic stretching. The main purpose of this study was to determine the intervention of the muscles quadriceps femoris (rectus femoris - vastus medialis) and biceps femoris and its relationship with the kinematics of the hip joint during a common ballistic stretching exercise.

Usability" is introduced, for the first time, as an ergonomics criterion concerning the developme... more Usability" is introduced, for the first time, as an ergonomics criterion concerning the development and functional evaluation of the muscular force qualities training programs, based on the use of biomechanics methodology. Thus, the main purpose of the present study is to introduce ergonomics applied to the training as a method to prevent WRMSDs (Work-Related Musculoskeletal Disorders) that cause the high loads and efforts as well as overuse, regarding mechanical work and power. "DynaSoft 2.0" is a 3D Inverse Dynamics package that allows for the evaluation of the developed mechanical loads during the repeated series of exercises in the training of muscular force qualities. "DynaSoft 2.0" makes possible the treatment of data not obtained from "turn-key systems" that could be too expensive, and, the user has the possibility to have by own the control of all analysis processes constructing purposeful anthropometric models.

Visual tracking of articulated motion is a complex task with high computational costs. Because of... more Visual tracking of articulated motion is a complex task with high computational costs. Because of the fact that articulated objects are usually represented as a set of linked limbs, tracking is performed with the support of a model. Model-based tracking allows determining object pose in an effortless way and handling occlusions. However, the use of articulated models generates a multidimensional state-space and, therefore, the tracking becomes computationally very expensive or even infeasible. Due to the dynamic nature of the problem, some sequential estimation algorithms like particle filters are usually applied to visual tracking. Unfortunately, particle filter fails in high dimensional estimation problems such as articulated objects or multiple object tracking. These problems are called dynamic optimization problems. Metaheuristics, which are high level general strategies for designing heuristics procedures, have emerged for solving many real world combinatorial problems as a way...

INTRODUCTION: During the aiming process in air rifle shooting from the standing position, shooter... more INTRODUCTION: During the aiming process in air rifle shooting from the standing position, shooters adopt a posture characterized by a pronounced extension with simultaneous lateral bend and slight twist of the trunk (coupled joint motion) with respect to the pelvic girdle, in order to align their eye with the rifle and the target. As consequence of the dynamic interactions of the parts of the shooter-rifle

INTRODUCTION Several ergonomic assessment tools can be used to make useful inferences about an in... more INTRODUCTION Several ergonomic assessment tools can be used to make useful inferences about an individual working on a given job in order to identify potential precursors of developing Work Related Musculoskeletal Disorders (WRMSDs) before workers develop symptoms severe enough to require medical treatment and to lead to work absenteeism and work disability. If these tools cannot be used preventively, when a workstation is designed, they have to be used in-situ during the work process in order to determine which specific jobs or worker characteristics are most likely to be the cause of the WRMSDs or worker performance problems and therefore redesign ergonomically unacceptable workstations. The basic idea behind every ergonomic assessment tool is that job physical demands should not exceed the worker physical capacities, because any mismatch of human physical capacities and human manual performance requirements in industry may produce, or aggravate, WRMSDs [1, 2]. The revised NIOSH l...

The main purpose of this study was to evaluate the quality of postural stability of persons affec... more The main purpose of this study was to evaluate the quality of postural stability of persons affected by different symptoms of cerebral palsy, and, on the other hand, to determine its relationship with the level of the neuromuscular potential of the subjects, evaluated on the base of their performance in the two-legged countermovement jump. The obtained results confirmed, first, significant differences between the subjects affected by hemiplegia and those affected by tetraparesis concerning the quality of postural stability, and, second, that the higher capacity for neuromuscular activity of the lower extremities is correlated with more stable posture. In this way, muscle strength seems to be a limiting factor in standing posture.

Paddle tennis coaches are lacking of scientific support in order to devise the most effective ind... more Paddle tennis coaches are lacking of scientific support in order to devise the most effective individual training program of stroke technique. Therefore, 30 kinematics and the temporal structure of the movements of three paddle tennis strokes have been analysed. Specifically, they have been calculated spatial-temporal variables of two successful trials of three main strokes (tray-smash, Hook-smash and Exit-wall drive) performed by a world class player.

The package “DinaSoft 1.0” is a software, developed in MATLAB environment, based in 3D Inverse Dy... more The package “DinaSoft 1.0” is a software, developed in MATLAB environment, based in 3D Inverse Dynamics. It also includes special designed modules for Digital Signal Processing, EMG analysis and Stabilometry. It admits data obtained from different commercial electronic systems and instruments and after processing allows technical and scientific staff to obtain feasible information concerning biomechanics and motor control of the standard fitness, training and rehabilitation exercises.

ISBS - Conference Proceedings Archive, Mar 18, 2009

SONIC DIGITIZING is a new and very precise method for kinematic analysis In shooting sports (Gian... more SONIC DIGITIZING is a new and very precise method for kinematic analysis In shooting sports (Gianikellis et al. 1992). The purpose of this study was to Improve the technical characteristics and capabilities of this method, also its applicability for complete Biomechanical Analysis in movements of high precision and shooting sports Now, the sampling rate 1s 66 6 Hz (Instead of the 37 Hz previously obtained frequency) divided by the number of emitters placed in an active volume of a cube with two meters side length. The Sonic Digitizer would be optionally faster working In smaller volumes (up to 100 Hz) In this way, we can use more ultrasound emitters sampling them within an appropriate rate for this class of motor patterns (according to Shannon s theorem). Also, the 3-d~mens~onaclo ordinates of the emitters are calculated respect to the system of reference by means of a Newton-Raphson's optimization algorithm This algorithm improves the precision of the system The calculated stan...

INTRODUCTION "Muscle strength is defined as the magnitude of the torque exerted by a muscle ... more INTRODUCTION "Muscle strength is defined as the magnitude of the torque exerted by a muscle (or muscles) in a single maximal isometric contraction of unrestricted duration" (Atha, 1981 ). Strength diagnosis (Schmidtbleicher, 1992) by means of strength and power tests is considered as a very useful procedure to identify talents or to control the evolution in the tralning or rehabilitation progress. The results of specific tests provide information about relative deficiencies and they can be used to figure out individual strength training programs. Also, maximum isometric force and the rate of force development seem to be important qualities related to the athletic performance (Wilson and Murphy, 1995). In consequence of this study a strain-gauge uniaxial load cell has been designed and developed to measure in real-time, and store the well established mechanical parameters to evaluate muscular force during isometric exercise. These parameters are: a) the peak value of the fo...

The purpose of this study is to analyze the individual rifle-shooting sport technique of an inter... more The purpose of this study is to analyze the individual rifle-shooting sport technique of an international level shooter defining the factors of mechanical instability that have negative effects on the performance. Kinematic and stabilometric data were registered by means of a sonic digitiser synchronised with a force platform. Postural stability has been evaluated for ten intervals of the last five seconds of the aiming time. Multivariate analysis techniques allowed to identify two factors of 'postural instability' that explain the 78.8% of the total variability. Namely, 'instability of the segment pelvis during the 7th interval of the aiming time' and 'instability of the structure that form the rifle and the supporting it upper trunk during the final second of the aiming line'. The results provide objective information respect to the motor patterns in the rifle-shooting justifying the proposed theoretical model for the identification of the postural stabilit...

INTRODUCTION It is well known that physically handicapped persons can participate in many sport m... more INTRODUCTION It is well known that physically handicapped persons can participate in many sport modalities. However, the disability of blind people is not compatible with shooting drills or archery. Our endeavor in this study is to establish the theoretical frame for the development of system that is able to generate in real time acoustical signals (feedback information) making possible the practice of shooting sports by persons with this kind of disability. To this purpose we use sonic digitizing to convert information respect to three-dimensional coordinates of ultrasound emitters to digital values, based on the properties of sound propagation. The measurement chain consists in a SAC Sonic Digitizer (GP8-3D) that communicates with a personal computer via a parallel interface (PI012), for higher data rate throughput, and a synchronized microphone sensor to detect the instant of triggering. The sampling rate of the sonic digitizer is 66.6 Hz divided by the number (k=3) of sound emit...


European Journal of Human Movement, 2010

The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neuroge... more The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neurogenics (stretch reflex), myogenics (viscoelasticity of the musculo-tendinous structures) and joint constraints. The main purpose of this study was to determine the intervention of the muscles quadriceps femoris (rectus femoris - vastus medialis) and biceps femoris and its relationship with the kinematics of the hip joint during a common ballistic stretching exercise. Kinematic data of the hip joint and EMGraphic data of the muscles quadriceps femoris (rectus femoris -vastus medialis) and biceps femoris were recorded by a measurement chain which consists of an EMG synchronized with an ELGoniometric system. The study yielded information concerning the sequence of muscular activation and the history of the angular velocity and acceleration of the hip joint during the defined phases of acceleration and deceleration of the flexion-extension movements. The obtained results confirmed statisticall...

Biomecánica

El análisis biomecánico del movimiento humano tiene aplicaciones, en el ámbito médico, ocupaciona... more El análisis biomecánico del movimiento humano tiene aplicaciones, en el ámbito médico, ocupacional y deportivo analizando la técnica y diseñando material deportivo de altas prestaciones. El objetivo de este trabajo ha sido presentar el software desarrollado en el Laboratorio de Biomecánica del Movimiento Humano y de Ergonomía de la Facultad de Ciencias del Deporte de la Universidad de Extremadura que permite analizar el movimiento humano normal y patológico. El paquete BiomSoft desarrollado en entorno MATLAB 5.3 permite el tratamiento y la representación de los datos procedentes del análisis biomecánico aplicando diferentes técnicas de suavizado e interpolación de los datos cinemáticos y cálculo de las magnitudes cinemáticas lineales y angulares, la creación y uso de una base de datos de parámetros inerciales, análisis dinámico inverso y determinación de los momentos musculares netos y del trabajo mecánico realizado, análisis espectral de los datos Electromiográficos y de Estabilome...

The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neuroge... more The aim of stretching exercises is to increase muscle-tendon flexibility which depends on neurogenic (stretch reflex), myogenic (viscoeiasticity of the musculo-tendinous structures) and joint constraints (Taylor et al. 1990; 1997). Among the other common techniques (passive, static and PNF) ballistic stretching is using the momentum of a moving body or a limb to force it beyond its normal range of motion. However, in spite of the exciting concerns of stretching neuromechanics, as well as, the overestimation of the role of connective tissue and the underestimation of the resistance of the muscles to stretch (Hutton, 1992), there is a lack of studies concerning the muscular activity in ballistic stretching. The main purpose of this study was to determine the intervention of the muscles quadriceps femoris (rectus femoris - vastus medialis) and biceps femoris and its relationship with the kinematics of the hip joint during a common ballistic stretching exercise.

Usability" is introduced, for the first time, as an ergonomics criterion concerning the developme... more Usability" is introduced, for the first time, as an ergonomics criterion concerning the development and functional evaluation of the muscular force qualities training programs, based on the use of biomechanics methodology. Thus, the main purpose of the present study is to introduce ergonomics applied to the training as a method to prevent WRMSDs (Work-Related Musculoskeletal Disorders) that cause the high loads and efforts as well as overuse, regarding mechanical work and power. "DynaSoft 2.0" is a 3D Inverse Dynamics package that allows for the evaluation of the developed mechanical loads during the repeated series of exercises in the training of muscular force qualities. "DynaSoft 2.0" makes possible the treatment of data not obtained from "turn-key systems" that could be too expensive, and, the user has the possibility to have by own the control of all analysis processes constructing purposeful anthropometric models.

Visual tracking of articulated motion is a complex task with high computational costs. Because of... more Visual tracking of articulated motion is a complex task with high computational costs. Because of the fact that articulated objects are usually represented as a set of linked limbs, tracking is performed with the support of a model. Model-based tracking allows determining object pose in an effortless way and handling occlusions. However, the use of articulated models generates a multidimensional state-space and, therefore, the tracking becomes computationally very expensive or even infeasible. Due to the dynamic nature of the problem, some sequential estimation algorithms like particle filters are usually applied to visual tracking. Unfortunately, particle filter fails in high dimensional estimation problems such as articulated objects or multiple object tracking. These problems are called dynamic optimization problems. Metaheuristics, which are high level general strategies for designing heuristics procedures, have emerged for solving many real world combinatorial problems as a way...

INTRODUCTION: During the aiming process in air rifle shooting from the standing position, shooter... more INTRODUCTION: During the aiming process in air rifle shooting from the standing position, shooters adopt a posture characterized by a pronounced extension with simultaneous lateral bend and slight twist of the trunk (coupled joint motion) with respect to the pelvic girdle, in order to align their eye with the rifle and the target. As consequence of the dynamic interactions of the parts of the shooter-rifle

INTRODUCTION Several ergonomic assessment tools can be used to make useful inferences about an in... more INTRODUCTION Several ergonomic assessment tools can be used to make useful inferences about an individual working on a given job in order to identify potential precursors of developing Work Related Musculoskeletal Disorders (WRMSDs) before workers develop symptoms severe enough to require medical treatment and to lead to work absenteeism and work disability. If these tools cannot be used preventively, when a workstation is designed, they have to be used in-situ during the work process in order to determine which specific jobs or worker characteristics are most likely to be the cause of the WRMSDs or worker performance problems and therefore redesign ergonomically unacceptable workstations. The basic idea behind every ergonomic assessment tool is that job physical demands should not exceed the worker physical capacities, because any mismatch of human physical capacities and human manual performance requirements in industry may produce, or aggravate, WRMSDs [1, 2]. The revised NIOSH l...

The main purpose of this study was to evaluate the quality of postural stability of persons affec... more The main purpose of this study was to evaluate the quality of postural stability of persons affected by different symptoms of cerebral palsy, and, on the other hand, to determine its relationship with the level of the neuromuscular potential of the subjects, evaluated on the base of their performance in the two-legged countermovement jump. The obtained results confirmed, first, significant differences between the subjects affected by hemiplegia and those affected by tetraparesis concerning the quality of postural stability, and, second, that the higher capacity for neuromuscular activity of the lower extremities is correlated with more stable posture. In this way, muscle strength seems to be a limiting factor in standing posture.

Paddle tennis coaches are lacking of scientific support in order to devise the most effective ind... more Paddle tennis coaches are lacking of scientific support in order to devise the most effective individual training program of stroke technique. Therefore, 30 kinematics and the temporal structure of the movements of three paddle tennis strokes have been analysed. Specifically, they have been calculated spatial-temporal variables of two successful trials of three main strokes (tray-smash, Hook-smash and Exit-wall drive) performed by a world class player.

The package “DinaSoft 1.0” is a software, developed in MATLAB environment, based in 3D Inverse Dy... more The package “DinaSoft 1.0” is a software, developed in MATLAB environment, based in 3D Inverse Dynamics. It also includes special designed modules for Digital Signal Processing, EMG analysis and Stabilometry. It admits data obtained from different commercial electronic systems and instruments and after processing allows technical and scientific staff to obtain feasible information concerning biomechanics and motor control of the standard fitness, training and rehabilitation exercises.