Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 14

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
This paper presents an assessment of the influence of isometric rotation of the lower limb in a standing position on the functioning of the muscles stabilizing the knee joint in the frontal plane with the use of modeling the loads on the musculoskeletal system. Methods: The research was carried out in the AnyBody Modeling System software, performing multi-variant simulations of the musculoskeletal system during isometric rotation of the lower limbs. The simulations were carried out using as input data the values of rotating moments and the ground reaction forces acting on foot segments, which were measured using the proprietary Rotenso device and the position of the body segments. Results: The result is the muscular activity of the lower limbs of the selected muscle groups during isometric rotation. Muscle activity was recorded for Sartorius, Tensor fasciae latae, Iliopsoas, Gluteus minimus, Gluteus medius, Gluteus maximus, Piriformis, Quadratus femoris, Obturator internus, Obturator externus, Gemellus inferior, Gemellus superior. Conclusions: Performing isometric rotation allowed for the activation of most of the knee joint stabilizing muscles and rotators of the lower limb. The results indicate that lower limb rotation exercises can be used in physiotherapy in patients with valgus knee.
EN
The study aimed to examine the influence of providing information about reacting to the heard musical stimuli while treadmill walking on physiological signals of participants. The study group consisted of 30 adults: group 1 was not informed how to react, group 2 received an instruction to adjust the frequency of steps to the music. The gait was carried out on a Zebris FDM-S treadmill for various sound stimuli using the Empatica E4 band to acquire electrodermal activity and heart rate. Information about moving to the stimuli did not change how the subjects responded physiologically during the test.
PL
Celem badania było sprawdzenie, czy informacje o sposobie reagowania na słyszane bodźce muzyczne podczas chodzenia na bieżni istotnie wpływają na sygnały fizjologiczne uczestników. W badaniu uczestniczyło 30 dorosłych: grupa 1 nie została poinformowana o tym, jak reagować na słyszane dźwięki, grupa 2 otrzymała polecenie dostosowania częstotliwości kroków do muzyki. Chód rejestrowano na bieżni Zebris FDM-S, a do akwizycji sygnałów fizjologicznych wykorzystano opaskę Empatica E4. Informacje o tym, jak reagować na bodźce nie zmieniały sygnałów fizjologicznych u badanych.
EN
Purpose: In clinical practice, motor development in infants is assessed subjectively. Many researchers propose objective methods, which have numerous limitations, by attaching markers or sensors to the child’s limbs. The purpose of this study is to attempt to develop objectified numerical indices to describe the limb movements of infants without interfering with spontaneous activity. Methods: 20-minute video recordings of three infants’ movements who were purposively selected from 51 subjects were included in the study. The procedure of automatic calculation of head position time in 3 positions was applied. Movement features were determined to allow for the delineation of coefficients describing the movement in numerical values. Results: Presented parameters describe three infant’s movement aspects: quality (strength), distribution of postural tonus and asymmetry in relation to head position, described as four independent values. Estimated parameters variability over time was weighted up according to expert observations. The presented method is a direct reflection of infants' observation, currently performed by highly educated and experienced therapists. Conclusions: The interpretability and usefulness of the presented parameters were proved. All parameters estimation is fully automated. The conducted research is a prelude to future work related to creating an objective and repeatable tool, initially monitoring and ultimately supporting early diagnosis for differentiating normal and abnormal motor development.
EN
Purpose: The aim of the study was to assess the possible use of biofeedback (information on the course and values of ground reaction forces (GRF) during landing following the performance of a dance evolution) for training minimising impact loads after a jump in modern dance. Methods: The tests involved the analysis of a total of 60 expressive elements of modern dance performed by 5 soloists. The tests involved the recording of the vertical component of GRF (GRFz) vector using Kistler platform in the landing phase following the performance of modern dance jumps. The dancers performed the above-named jumps three times in successive tests: a reference test (without biofeedback) and the next two tests with biofeedback, after the obtainment of information about the vertical value of GRF. After each performance, the dancers watched a course of GRF and films showing the recorded landing phase. Results: Applying of a proposed didactic laboratory session led to: extension of contact time and of time preceding the obtainment of the maximum value of GRFz, reduction of the maximum values of the vertical components of the GRF, reduction of the loading rate of the ground reaction force, increase of an impulse of the vertical component of GRF in the entire stance phase and in the shock absorption phase. Conclusions: Proposed didactic laboratory session with biofeedback may result in the change of the post-jump shock absorption technique.
EN
Purpose: The aim of this study was to develop a method to implement muscle forces to a numerical model of a dummy and to evaluate the effect of muscle activation on driver behavior during a frontal collision. The authors focused on the forces acting at the knee, hip, and elbow joints. Methods: The authors carried out torque measurements in joints using the Biodex System 4. Then, the previously developed numerical models were modified by introducing the joint torque values. Moments of force were introduced as a function of the rotation angle. During research, numerical simulations were carried out in three stages: in the first stage, a full vehicle crash was analyzed to determine the change of velocity of the vehicle interior; in the second stage, subsidence of the system was realized; in the third stage, a frontal crash was simulated. The models considered the operation of the sensors, airbag and seat belt tensioning system. Results: A numerical model with the active response of the dummy to the change in position during impact was developed. The results of the dynamic analysis were used to analyze the impact of muscle activation on dummy behavior. The change in shoulders rotation angle, the lateral and vertical displacement of the dummy’s center of gravity, and the forces acting between the dummy and the seat belt were compared. Conclusions: The effect of muscle action on the behavior of a dummy during a frontal collision was determined.
EN
Purpose: This work aimed to define the impact of the introduction of power and speed dry-land training in female swimmers aged 15–16 on the rise of time results at a distance of 200 m and on the increase of the strength level of the muscle groups in the elbow joint. Method: The investigations were conducted on a group of 28 junior female swimmers: group 1 (aged 13–14) with speed and endurance training based on “water” exercises; group 2 (aged 15–16) with extra power and speed dry-land training. The following parameters were analyzed: time results, the moments of muscle forces in the elbow joint at the extension and flexion movements in isokinetic conditions and the ratio of the values of moments of muscle forces of flexors in relation to extensors. Results: Statistically significant differences between groups were found for the following parameters: the time results from swimming 200 m with ( p < 0.001) and without using lower limbs ( p = 0.031), the ratio of the moments of muscle forces of flexors to extensors ( p < 0.05). Conclusions: The results of the correlation analysis show that the higher the moments of muscle forces of flexors and extensors of the elbow joint, the shorter the time obtained in swimming 200 m in the freestyle stroke.
EN
Purpose: The proper shape of the foot determines its proper functioning and efficiency, which is significant as far as dancers are concerned. The aim of the study was to identify the arch of feet based on the Arch Index (AI), ability to maintain balance on the basis of stabilometric parameters and the distribution of loads acting on the feet of professional folk dancers. Methods: The study group was composed of 37 folk dancers and the reference group consisted of 56 healthy adults aged 19–45. Balance measurements were performed using the Zebris FDM-S measurement platform, Romberg test with eyes open. Test results were exported to the Matlab 2019b computing environment. The algorithm developed by the Authors in relation was used to calculate Arch Index for the right and left foot, for each test participant separately. Results: Statistical tests did not reveal statistically relevant differences between stabilometric parameters and loads affecting feet in the reference group and that of the dancers. The statistical tests revealed that the value of the AI differed significantly in the reference group and in the group of professional folk dancers (p = 0.05). The differences were also observed in the group of females (p = 0.003). No statistically relevant differences were observed in relation to the group of males (p = 0.116). The percentage of the feet with high arch in the group of dancers amounted to 26%; 33% of dancers’ feet were classified as the feet with low arch. Conclusions: The feet of professional folk dancers have a statistically more arched foot than the reference group.
EN
Purpose: The work aimed to assess the functioning of the musculoskeletal system within the lumbar spine in relation to everyday postures of sitting and standing. Methods: The comparative analysis was based both on experimental tests and computer simulations performed in the AnyBody Modeling System environment. Input data used to prepare models were based on the information obtained in experimental tests. The test participants were tasked with adopting two postures: 1) standing position and 2) sitting position. Kinematics measurements were performed using the Zebris ultrasonic system. During sitting position, the tests additionally involved the use of a dynamometric platform measuring reaction forces occurring between buttocks and the seat. Results: The comparative analysis included measurements of the trunk inclination angle and the pelvic inclination angle as well as results of computer simulations. The sitting posture is responsible for increased trunk inclination and a change in the position of the pelvis. In terms of the sitting position, it was possible to observe an increase in the loads affecting individual intervertebral joints of the lumbar spine by 155–184% in comparison with the standing posture (100%). Simulations revealed an increased muscle activity of the erector spinae, abdominal internal oblique muscles and abdominal external oblique muscles. Conclusions: Adopting a sitting position increases the loads on the lumbar spine and increases the activity of the erector spinae and abdominal muscles compared to the standing position, which is caused by change in the position of the pelvis and the curvature of the lumbar region.
EN
Purpose: The research work aimed to perform the mathematical modelling-based assessment concerning the effect of the position of the pelvis in the sagittal plane on loads present in the musculoskeletal system in the standing position. Methods: The analysis of the effect of various positions of the pelvis was performed using the Free Posture Model in the AnyBody Modeling System software. Simulated positions involving various values of pelvis inclination ranged from the extreme pelvic retroposition (–7°) through normative values (0–23°) to the extreme pelvic anteversion (33°). Results: The lowest resultant reaction forces in the intervertebral joints recorded for an angle of inclination restricted within the range of 9–27° and segment L5–S1 amounted to less than 0.7 BW. A change in the pelvic inclination from the normative values towards retroposition or anteversion resulted in the increased muscular activity of the erector spinae, transverse abdominal muscles as well as internal and external oblique muscles. Regarding the lower limbs, changes in the activity were observed in the biceps femoris muscle, iliac muscle, gluteus minimus, gluteus medius and the gluteus maximus. Conclusion: The results obtained in the research-related tests confirmed that the pelvic inclination affects loads present in the musculoskeletal system. The abovenamed results will be used to develop therapeutic exercises aimed to reduce loads present in the musculoskeletal system. The aforesaid exercises will be used to teach participants how to properly position their pelvis and how to activate individual groups of muscles.
EN
The objective of the work was to define a new comprehensive method of evaluating gait pathology (Gait Kinematics Index, Global Symmetry Index and Gait Deviations Profile). Methods: The article presents in detail a mathematical algorithm of a new comprehensive method of evaluating gait pathology. Input data for the algorithm are the kinematic parameters of gait. The method is based on the determination of the following parameters: standardized angular variables (Wji), kinematic indicators of gait (KIj), gait cycle indicators (GCIi), Gait Kinematic Index (GKI), Gait Deviations Profile (GDP, GDPj), Global Symmetry Index (GSI) and Symmetry Indices (SIj) for kinematic gait values. The algorithm is based on the determination of the difference between results obtained in relation to the kinematics of movement of a given patient and the average value obtained in relation to the standard in each percentage of a gait cycle. The proposed method was tested using results obtained for 59 healthy persons and one patient with locomotor function disorder. Results: The GKI values for the reference group amounted to 0.89 ± 0.23. Information which can be obtained using the proposed gait assessment method was presented using an example of a patient with the disorder of locomotor functions. Areas of gait deviations, which were identified on the basis of the determined indicators, were presented in a graphic form using GDP. Conclusions: The new gait assessment method makes it possible to identify gait using a single numerical value, evaluate movements in individual joints and in subsequent moments as well as to assess the symmetry of gait.
EN
Analysis of human gait as well as diagnosis of human locomotion organ should always be conducted with velocity of gait equal to Preferred Walking Speed (PWS). The literature review shows that the PWS value is not the same in real and virtual environment. The aim of this study was to determine PWS values in both environments and to specify values of parameters used in equations enabling PWS calculations on the basis of lower limb length. Methods: Research-related tests involved 40 subjects walking on the treadmill and wearing HMD goggles. The spatial scenery made participants feel like during a walk in the park. The tests included measurements of displacements of the COP, allowing for the calculation of the Lyapunov exponent and Floquet Multiplier. Both coefficients were used to identify stability at various gait velocities. Results: The analysis revealed that the PWS in relation to gait on the treadmill with VR was lower than the PWS without VR. The final stage of research involved the determination of new values of coefficients of the formula enabling the identification of the velocity of comfort of gait in VR. Conclusions: Obtained results proved that PWS in real and virtual environment are different. The lower values were obtained for measurements in VR. On the basis of these results, value of the “a” coefficient, used in PWS calculations on the basis of lower limb length, was re-determined. The new value makes it possible to assess PWS for gait conducted on treadmill in virtual environment, what can be very important in gait evaluation.
PL
W pracy dokonano oceny biomechanicznej funkcji lokomocyjnych weterana wojennego. Uzyskane dla weterana wojennego wyniki ilościowej analizy chodu porównano z wartościami otrzymanymi dla grupy 56 zdrowych osób dorosłych, bez zaburzeń w obrębie narządu ruchu. Badania doświadczalne przeprowadzono z wykorzystaniem systemu optoelektronicznego BTS Smart. Analizie porównawczej poddano parametry czasowo-przestrzenne i kinematyczne chodu oraz zmiany energii całkowitej, potencjalnej, wypadkowej energii kinetycznej w czasie chodu. Uzyskane dla weterana wojennego wyniki znacznie odbiegały od wartości/zakresów normatywnych, wskazując na znaczne obrażenia aparatu ruch, które poniósł podczas wybuchu improwizowanego urządzenia wybuchowego.
EN
In the work the biomechanical evaluation of locomotion functions of a war veteran was made. The results of the quantitative gait analysis obtained for a war veteran were compared with the values obtained for a group of 56 healthy adults without locomotor disorders. Experimental studies were carried out using the BTS Smart optoelectronic system. The spatiotemporal and kinematic parameters of gait as well as changes in total energy, potential energy, kinetic energy and its components during gait were subjected to comparative analysis. The results obtained for a war veteran differed significantly from normative values / ranges, indicating significant injuries to the apparatus, which he suffered during the explosion of the improvised explosive device.
EN
The quality of body posture and its balance depends on the efficiency of the receptors, the good work of the central nervous system integrating and coordinating the postural system and the effective musculoskeletal system. Physical activity of people with intellectual disability can stimulate the processes of improving the posture and its postural stability, improving the quality of life. Methods: The study was conducted in 2017. 20 randomly selected volleyball players with intellectual disabilities and 10 healthy players took part in it. Body posture was recorded using a photogrammetric system. To evaluate the use of the Frohner Posture Index and the Dolphens classification, stability of the posture was assessed on the Zebris FDM power plate, analyzing the basic stabilographic parameters sway path and sway area. Results: Athletes with intellectual disabilities had significantly poorer posture and body balance than healthy players. There were no differences in postural stability between the groups studied. Some linear correlations were found between the quality of posture and balance and stabilographic variables. Conclusions: Incorrect postural patterns, observed in people with intellectual disabilities, require the development of special recovery programs. Qualified physical activity can help them improve their balance systems, reducing the risk of falls and injuries. The lack of the possibility of an unequivocal relationship between the quality of body posture and its stability requires research on a larger research material. New evaluation methods used (Frohner Posture index and Dolphens classification) confirmed their usefulness and gave new possibilities of application in postural research.
EN
The objective of the work was to determine biomechanical parameters influencing loads affecting the musculoskeletal system and shock absorption during the landing phase in Grand Jeté, Entrelacé and Ballonné. Methods: Motion kinematics measurements of the landing phase in GrandJeté, Entrelacé and Ballonné were carried out using the optical APAS system, and measurements of the GRF components – using Kistler platform. The research was carried out for three professional dancers. Kinematic and kinetic parameters of the landing were analysed. Results: The mean maximum GRF value in relation to the classical dancer amounted to 8.16 ± 1.37 N/BW. During landing, the joints of the lower limb are affected by external force moments of high values (ankle – 3.04 ± 0.54 [Nm/BW], knee – 7.56 ± 5.53 [Nm/BW], hip – 10.97 ± 6.80 [Nm/BW]). The maximum value of the external force moments in the joint were strongly negatively correlated with the value of the angle in the hip joint at the moment of the first contact with the ground. It was noticed that the obtainment of maxGRF was preceded by a decrease in kinetic energy of approximately 50%. Conclusions: Factors affecting loads present in the musculoskeletal system during the shock absorption of a leap are: GRF values, the values of external force generated inside the joints and a change in the value of kinetic energy. The safe shock absorption after landing is influenced by properly positioned limb at the moment of the first contact, a greater range of movements in the joints and longer time from the moment of the first contact to the obtainment of maxGRF.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.