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1

The overview of challenges in detecting patients’ hazards during robot-aided remote home motor rehabilitation

Wilk Julia, Falkowski Piotr, Osiak Tomasz

Journal of Automation Mobile Robotics and Intelligent Systems

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2023

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Vol. 17, No. 4

17--27

EN

Minimally-supervised home rehabilitation has become an arising technological trend due to the shortages in medical staff. Implementing such requires providing advanced tools for automatic real-time safety monitoring. The paper presents an approach to designing the mentioned safety system based on measurements and modelling the interface between a patient’s musculoskeletal system and a rehabilitation device. The content covers the segmentation of patients regarding their health conditions and assigns them suitable measurement techniques. The defined groups are described by the hazards with which they are most endangered and their causes. Each case is correlated with the appropriate data type that may be used to detect potential risk. Moreover, a concept of using presented knowledge for tracking the safety of bones and soft tissues according to the biomechanical standards is included. The paper forms a set of guidelines for designing safety systems based on measurements for robot-aided home kinesiotherapy. It can be used to select an appropriate approach regarding a specific case; which will decrease costs and increase the accuracy of the designed tools.

2

Redistribution of knee and ankle joint work with different midsole thicknesses in non-rearfoot strikers during running: a cross-sectional study

Miyazaki Tomohiro, Aimi Takayuki, Nakamura Yasuo

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 1

79--90

EN

The aim of this work was to i nvestigate the effects of midsole thickness on non-rearfoot strike runners’ redistributions of knee and ankle joint negative and positive work. Methods: Fourteen healthy male runners wore minimalist, traditional and maximalist shoes and ran in a straight line in each shoe in the laboratory at a speed of 15 km/h, with a ±5% difference being allowed. Whole-body kinematics and ground reaction forces were recorded, and the data of eleven non-rearfoot strikers were used for the analysis. Ankle and knee joint negative and positive work was calculated by integrating each joint’s torque power. Friedman test was used for statistical comparisons. Results: Running in minimalist shoes induced significantly greater ankle joint negative and positive work than in other shoes. Running in maximalist shoes induced significantly lower ankle joint positive work and greater knee joint negative work than in other shoes, and significantly greater knee joint positive work than in minimalist shoes. Conclusions: Our results indicated that nonrearfoot strikers redistributed joint negative and positive work from the knee to the ankle when using minimalist shoes or from the ankle to the knee when using maximalist shoes. It is recommended that future research employs more rigorous study designs, such as randomised controlled trials and longitudinal studies, to provide a more accurate assessment of the effect of these shoes on injury rates.

3

Microstructural and Micromechanical Tests of Titanium Crowns

Ryniewicz Wojciech, Bojko Łukasz, Pałka Paweł, Osada Piotr, Ryniewicz Andrzej

Tribologia

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2022

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nr 4

61--72

EN

Fixed prosthetic restorations must meet the health requirements in terms of the protection of the tissues of the oral cavity, biomechanical requirements for optimal tissue stress and the strength and wear resistance of the structure, aesthetic requirements related to the location of the gingival margin, as well as the shape, thickness, and colour of the veneers. The aim is to evaluate the impact of manufacturing technology on the microstructure and micromechanical parameters of titanium crowns. The material of the analysis are prosthetic crowns made of Ti6Al4V alloy for the maxilla premolars and the mandible molars, produced using two technologies: Selective Laser Melting (SLM) and CAD/CAM milling. Crown structures were evaluated on the basis of examinations of the microstructure and surface layer of the chamfers, micromechanical parameters in axial sections perpendicular to the dental arches, and the accuracy of mapping the internal shape in sections with horizontal planes perpendicular to the axis of the abutment tooth. The results of this work can be used in a clinical setting. They allow the evaluation of what is the impact of the technology of producing the supporting substructure on the structure of the prosthetic crown. The strength requirements in both technologies are met, while the higher value of the microhardness of the titanium SLM substructure, compared to the milled one, increases the stiffness of the structure under conditions of biomechanical excitation. The errors in mapping the internal shape of the crowns are comparable and slightly higher during sintering.

PL

Stałe uzupełnienia protetyczne powinny spełniać wymagania zdrowotne w aspekcie zabezpieczenia tkanek jamy ustnej, wymagania biomechaniczne dotyczące optymalnego wytężenia tkanek oraz wytrzymałości i odporności na zużycie konstrukcji, wymagania estetyczne związane z usytuowaniem obrzeża dodziąsłowego, a także kształtem, grubością i kolorem licowania. Celem jest ocena wpływu technologii wytwarzania na mikrostrukturę i parametry mikromechaniczne koron tytanowych. Materiałem analizy są korony protetyczne ze stopu Ti6Al4V na zęby przedtrzonowe szczęki i trzonowe żuchwy wytwarzane dwoma technologiami: Selective Laser Melting (SLM) i frezowania CAD/CAM. Konstrukcje koron oceniano na podstawie badań mikrostruktury i warstwy wierzchniej stopni, parametrów mikromechanicznych w osiowych przekrojach prostopadłych do łuków zębowych oraz dokładności odwzorowania kształtu wewnętrznego w przekrojach płaszczyznami horyzontalnymi, prostopadłymi do osi zęba filarowego. Wyniki tej pracy mogą być wykorzystane w warunkach klinicznych. Pozwalają ocenić, jaki jest wpływ technologii wytworzenia podbudowy nośnej, na konstrukcję korony protetycznej. Wymagania wytrzymałościowe w obu technologiach są spełnione, przy czym wyższa wartość mikrotwardości podbudowy tytanowej z SLM, w porównaniu do frezowanej, wpływa na zwiększenie sztywności konstrukcji w warunkach wymuszeń biomechanicznych. Błędy odwzorowania kształtu wewnętrznego koron są porównywalne i nieco wyższe przy spiekaniu.

4

Próby potrąceniowe z użyciem manekinów pieszego. Manekin pieszego PRIMUS - konstrukcja i unikalne cechy

Wdowicz Daniel

Paragraf na Drodze

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2022

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Nr 3

57--69

PL

W artykule pokrótce przedstawiono modele manekinów zderzeniowych pieszych, dzieląc je na manekiny stosowane typowo na potrzeby projektowania pojazdów oraz stosowane w badaniach rekonstrukcyjnych wypadków drogowych. Przedstawiono wybrane badania z dziedziny rekonstrukcji wypadków drogowych, w których wykorzystywane były manekiny pieszych. W drugiej części artykułu przedstawiono konstrukcję manekina PRIMUS - produktu od niedawna dostępnego na rynku. Opisano budowę manekina i podsumowanie badań weryfikujących jego odpowiedź dynamiczną w warunkach potrącenia oraz wymieniono potencjalne jego zastosowania, takie jak rekonstrukcje wypadków i badania eksperymentalne na potrzeby przemysłu.

EN

The article presents various models of pedestrian crash test dummies, grouping them by their applicability: vehicle manufacture or road accident reconstruction. Selected experiments in the latter area using dummies of pedestrians are presented. The second part of the article is devoted to a description of a PRIMUS dummy - a relatively new product on the market. The structure of the dummy is presented, and studies verifying the dynamic response of the dummy in a collision with pedestrian are summarized. The application of the dummy in road accident reconstruction and R&D experiments are presented.

5

Metody inżynierskiej analizy obrażeń z wykorzystaniem liczbowych kryteriów biomechanicznych

Kędziora Krzysztof

Paragraf na Drodze

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2022

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Nr 3

25--40

PL

W artykule omówiono kryteria biomechaniczne, które mogą być przydatne do ilościowej analizy obrażeń uczestników wypadków drogowych, m.in. w zakresie obrażeń głowy, szyi, klatki piersiowej oraz kończyn dolnych. Kryteria te wyznacza się na podstawie analizy charakterystyk czasowych przyspieszenia, prędkości, przemieszczeń, a także sił i momentów sił (różne w zależności od rodzaju wskaźnika). Omówienie kryteriów przeprowadzono w oparciu o przykładowe obowiązujące w Europie normy z zakresu bezpieczeństwa, m.in. Regulamin 80 EKG/ONZ (dotyczący testów zderzeniowych w pojazdach M2, M3), Regulamin 129 (dotyczący testów fotelików dziecięcych) oraz normy brytyjskiej GMRT2100 (dotyczącej bezpieczeństwa pasażerów w transporcie kolejowym). Uwzględniono również wyniki własnych badań symulacyjnych. Niektóre z przedstawionych wskaźników oceny obrażeń zostaną zaimplementowane do wielobryłowego modelu ciała człowieka w programie V-SIM.

EN

The article discusses the biomechanical criteria that may be useful in the quantitative analysis of injuries to road accident participants, e.g. in terms of head, neck, chest, femur and tibia injuries. These criteria are determined on the basis of the analysis of the time characteristics of acceleration, velocity, displacement, as well as forces and moments of forces (different depending on the type of indicator). The discussion of the criteria in this article is based on examples of safety standards in force in Europe, including Regulation 80 of the UN/ECE concerning crash tests in M2, M3 vehicles, Regulation 129 concerning the tests of child seats and the British standard GMRT2100 concerning the safety of passengers in rail transport. The results of simulation tests done by the author of the article were also taken into account. Some of the injury assessment indicators presented will be implemented into the MULTIBODY human body model in the V-SIM program.

6

A kinematic analysis of the basketball shot performance: impact of distance variation to the basket

França Cíntia, Gouveia Élvio Rúbio, Coelho-E-Silva Manuel J., Gomes Beatriz B.

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 1

159--166

EN

The aim of the current study was to examine the variation on the kinematic parameters in the basketball shot associated with the shooting distance. Methods: Twenty-seven female adolescent basketball players aged 12.1 ± 0.9 years completed 10 BS trials from a frontal position of 4.75 m and 5.75 m from the basket. Nine anatomical markers were placed on the participants’ dominant side to assess the kinematic variables. The following variables were analyzed: angle, velocity, and height at ball release; centre of mass horizontal displacement and maximum height attained; maximum hip height and hip height at release; shoulder, elbow, and knee angular position and velocity at ball release; deepest knee flexion during the preparatory phase; the peak of the angular velocity of the shoulder, elbow, and knee joints. Results: At release, the angle decreased while velocity increased significantly at 5.75 m. During the release, greater shoulder flexion and increased joint (shoulder and knee) angular velocity were observed. The deepest knee flexion and the centre of mass horizontal displacement were accentuated at 5.75 m. The ball release occurred before the peak of the jump phase. Conclusions: To compensate for the long ball trajectory to the basket, participants perform a set of adjustments in the body segmental organization to increase the ball velocity at release. The coaches’ feedback should focus on the shooting arm’s positioning and in the jump phase (to jump as close to vertical as possible). Also, a consistent shooting technique should be acquired close to the basket before expanding the shooting range.

7

Pulse wave propagation along human aorta: a model study

Kizilova Natalya, Mizerski Jeremi, Solovyova Helen

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 1

17--34

EN

In the study, wave propagation along aorta is studied for different normal and pathological conditions in distal arteries. The mathematical model is based on the axisymmetric incompressible Navier-Stokes equations for blood and momentum equations for an incompressible viscoelastic arterial wall. The solution has been found as a superposition of forward and backward running waves. The blood pressure and flow curves measured by ultrasound in larger systemic arteries of ten healthy volunteers have been used for identification of the model parameters. It is shown that individual geometry plays an essential role in the location of positive and negative wave reflection sites along the aorta and, thus, in the pressure and flow patterns as well as blood distribution into the side branches. The model is validated by comparative study with the same dependencies computed previously on a 55-tube model as well as on the measurement data. The model can be used for determination of the individual parameters for patient-specific cardiovascular models and further in silico modeling of the outcomes of surgical and therapeutic procedures.

8

Comparison of pre- and post-implantation mechanical behavior of composite hernia meshes

Kirilova-Doneva Miglena, Pashkouleva Dessislava, Sopotensky Stoyan, Petrova Guenka

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 3

769--778

EN

Implantation of synthetic meshes provokes complications which require long-lasting follow-up. The mesh materials exposed to physiological conditions demonstrate differences in failure load, stiffness and extension. Mechanical alterations of explants made of polyester were investigated using a uni-axial tensile test and a relaxation test. The tensile strength of the explanted meshes changed in the transversal direction. The elastic modulus in the same direction increased two times. A magnified mesh image displayed mesh alteration. The relaxation tests revealed that the initial stress decreases after implantation while the reduction of stress increases in the interval 50%-96.6%.

9

Developing a multiscale in silico cornea for understanding the role of cell mechanics in corneal pathologies

Pant Anup, Paul Elliot, Vahdati Ali

Biocybernetics and Biomedical Engineering

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2020

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Vol. 40, no. 4

1369--1377

EN

Multiscale in silico modeling of the cell-tissue-organ units is an emerging area of research with the potential to improve our understanding of various disease pathogenesis. Using a multiscale modeling approach, we developed a computational model of the human cornea to investigate how the application of macroscale loads may alter the micro-mechanical environment of the cells. We then utilized the multiscale model to study the effect of physiological and non-physiological mechanical loading conditions such as intraocular pressure (IOP) loading, IOP spike, and eye-poking on the corneal cells. On comparing the results obtained under increased IOP and eye-poking loading, we observed large differences in the averaged principal stress magnitudes in the immediate vicinity of the cell through the thickness of the cornea. On the other hand, our model predicted that under physiological IOP loading, the average principal strain magnitudes in the immediate vicinity of the cell remained almost constant irrespective of the cell location in the stroma. To our knowledge, this is the first study that investigates the effect of mechanical loading on the corneal cells through a multiscale modeling framework. Our computational multiscale cornea model provides a platform to perform virtual experiments and test hypotheses to further our understanding of the potential mechanical cause of multiple diseases in the cornea.

10

Wybrane bazodanowe zbiory informacji z zakresu biomechaniki, fizjologii i psychologii

Sygocki Witold, Baka Łukasz, Bugajska Joanna, Biernacki Andrzej

Bezpieczeństwo Pracy : nauka i praktyka

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2020

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nr 5

21-25

PL

Deponowanie wyników badań naukowych - zarówno opracowanych, jak też tzw. surowych danych - odbywa się pod wieloma postaciami, poprzez zamieszczanie w repozytoriach danych badawczych, umieszczanie wyników w publikacjach, które są następnie indeksowane na platformach czasopism, w bazach bibliograficzno-abstraktowych Niektóre czasopisma funkcjonujące w obiegu międzynarodowym wymagają od autorów dołączania do artykułów także zbiorów z danymi, bądź zdeponowania ich w jednym z ogólnodostępnych repozytoriów danych badawczych. W artykule zaprezentowano wybrane bazy danych, dostarczających informacji o wynikach badań m.in. z zakresu biomechaniki, fizjologu, psychologii.

EN

Depositing scientific research results - both research and raw data - takes place in many forms, by depositing research data: in repositories, as results in publications, which are then indexed on publisher's platforms, and in bibliographic and abstract databases and informing about obtained results research. Some international journals require authors to attach data collections to their articles, or to deposit them in one of the publicly available research data repositories. The following publication is a presentation of selected databases providing information on research results, including in the field of biomechanics, physiology, psychology.

11

Ocena stabilności posturalnej w funkcji różnego ustawienia stóp na podłożu przy wykorzystaniu miar dynamiki nieliniowej

Kędziorek Justyna, Błażkiewicz Michalina

Aktualne Problemy Biomechaniki

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2020

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z. 19

20--26

PL

Celem pracy była ocena stabilności posturalnej w różnych warunkach podparcia: stanie obunóż, jednonóż i w tandemie przy oczach otwartych. W badaniach wzięła udział grupa trzydziestu trzech zdrowych osób w wieku 21.88 ± 1.65 lat. Badania zostały przeprowadzone przy użyciu platformy AMTI AccuSway (30 sekund – każda próba). Do obliczeń eksportowano położenia środka nacisku stóp na podłoże (CoP) w płaszczyznach x i y. Następnie została policzona długość drogi CoP i współczynniki dynamiki nieliniowej: entropia próbkowa, wymiar fraktalny i wykładnik Lapunowa. Wykazano, że zmniejszenie pola powierzchni podparcia powoduje istotny wzrost współczynnika entropii próbkowej i wymiaru fraktalnego.

EN

The aim of the study was to assess postural stability under different base of support: both foot standing, one-leg standing and tandem with eyes open. A group of thirty-three healthy persons aged 21.88 ± 1.65 years participated in the study. The tests were carried out using the AMTI AccuSway platform. The locations of the center of foot pressure (CoP) in the X and Y planes were exported. Then the CoP path length and nonlinear dynamics coefficients were calculated: sample entropy, fractal dimension and Lapunov exponent. It has been shown that the reduction of the support surface area causes a significant increase in the sample entropy factor and the fractal dimension.

12

Muscle torque production and kinematic properties in post-stroke patients: a pilot cross-sectional study

Kowal Mateusz, Kołcz Anna, Dymarek Robert, Paprocka-Borowicz Małgorzata, Gnus Jan

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 1

11--20

EN

Stroke-related hemiplegia is an important factor influencing parameters of gait. So far, limited papers have assessed temporo-spatial capabilities and their correlations with gait parameters in the early post-stroke stage. This pilot study evaluated the temporospatial parameters of gait and assessed the maximal isometric and isokinetic torque production of the plantar flexor and dorsiflexor muscles. Methods: 15 patients with lower limb spasticity and 15 healthy controls were included. Stroke severity was assessed using the Modified Ashworth Scale and the Barthel Index. Gait cadence, gait speed, and gait cycle were assessed using inertial sensors during a Timed Up and Go test. Maximal isometric and isokinetic torque production of the ankle plantar flexor and dorsiflexor muscles were assessed using an isokinetic dynamometer device. Results: Post-stroke patients had statistically significantly lower gait cadence than healthy participants (17%, p < 0.05). Statistically significantly lower values of vertical acceleration were also noted during a sit-to-stand movement task (42%, p < 0.05). Plantar flexion torque of the affected limb was significantly different during isometric (63%, p ≤ 0.01) and isokinetic work for 30o /s (49%, p = 0.04), 60o /s (58%, p = 0.01) and 20 °/s (53%, p = 0.01). Dorsiflexor muscles’ torque production was significantly different in isometric activity (38%, p = 0.04). A statistically significant positive correlation occurred between the absolute peak torque of the dorsiflexor muscles in both static and speed phases of gait (Rs = 0.65, p = 0.04). Conclusions: Despite the low intensity of spasticity and early phase after stroke, differences in the muscle torque production and temporo-spatial parameters, as well as the correlations between them, were noticeable.

13

Gender differences and relationships between upper extremity muscle strength, lower limb power and shuttle velocity in forehand smash and jump smash in badminton

Ferreira Anna, Górski Michał, Gajewski Jan

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 4

41--49

EN

The aim of the study was to investigate the relationships between shuttlecock velocity during a badminton forehand smash with and without jump (VmaxWJ and VmaxNJ), strength of upper limb muscles, vertical jump height and to analyze differences in these parameters for each gender. Methods: The study examined members of the Polish National Badminton Team seven women and seven men. A special torque meter was used to assess the strength of the upper limb muscles. Vertical jumps were performed on an AMTI force plate. Shuttlecock velocity was measured using Vicon motion capture system. Results: Differences between the right and left limbs were observed in all muscle groups except shoulder flexion for both genders. The results of all measured parameters: torques, height of countermovement and spike jump (HACMJ, HCMJ, HSPJ), VmaxWJ and VmaxNJ, were greater for men than for women. No statistically significant differences were found between VmaxWJ (men: 83.27 ± 4.83 m/s; women: 67.57 ± 4.21 m/s) and VmaxNJ (men: 84.19 ± 6.05 m/s; women: 69.70 ± 6.53 m/s) within the same gender. Positive correlations were found between both HCMJ and HSPJ regarding VmaxWJ in men; the height of shuttlecock impact in jump smash (HWJ) and HSPJ in women; proving the importance of jumping ability in badminton. Negative correlations were found between HWJ and VmaxWJ for both genders. Conclusions: The jump before smash is not used in order to hit the shuttle from the highest point, but to gain time to correctly prepare the phase of stroke while being in the air.

14

Evaluation of stabilization of intra-articular fracture of distal humerus – finite element study

Kruszewski Arur, Piszczatowski Szczepan, Piekarczyk Piotr, Kwiatkowski Krzysztof

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 1

153--163

EN

The treatment of comminuted fractures of distal humerus poses a challenge for orthopaedics. Previous studies assessing the global stiffness of the bone – stabilizer system – made it impossible to explicitly indicate an optimal configuration of the locking plates in the treatment of this kind of fractures. The aim of the present research was to comparatively analyze the stabilization conditions of intraarticular fractures of distal humerus with the use of various configurations of the stabilizer. Methods: The research was based on the analysis of mutual displacements of bone fragments. Such evaluation was performed with the use of numerical simulation conducted with the use of the finite element method. A realistic model of humerus was based on the CT data. Three spatial configurations of the stabilizer (parallel, posteromedial and posterolateral) were considered. The mutual displacements of bone fragments as well as the deformity of the stabilizer under various loading conditions were analyzed. Results: In most cases, the parallel setting of the plates ensures a better stabilization of the bone fragments than the perpendicular configuration. The most difficult conditions of stabilization were obtained for the lateral bone fragment. The value of the fragments’ displacements significantly increases for loading directions occurring with ascending flexion angle of the joint. Conclusions: In most cases, the parallel setting of the plates ensures a better stabilization of the bone fragments than the perpendicular configuration.

15

Body composition and specific and general strength indices as predictors of 100-m front crawl performance

Strzała Marek, Stanula Arkadiusz, Krężałek Piotr, Sadowski Wojciech, Wilk Robert, Pałka Tomasz, Sokołowski Kamil, Radecki-Pawlik Artur

Acta of Bioengineering and Biomechanics

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2020

|

Vol. 22, no. 4

51--60

EN

The purpose of this research was to examine the impact of body composition on the anaerobic ability to generate strength and power produced separately by upper and lower limbs during dry-land and in-water (propulsion force) tests. Further examination included the influence of all gathered anaerobic strength indices on the results of 100-m front crawl race. Methods: The study involved 26 male swimmers (age: 19.8 ± 2.48 years). Fat-free mass, total body water and muscle mass of arms, legs, and trunk were measured. Dry-land average work, maximal power generated in 40-second arm-cranking test, and work generated in 20 countermovement jumps were evaluated. The forces generated separately by arms and legs were assessed during 40-second tethered swimming. All indices of body composition were found strongly correlated with indices of average work and maximal power generated by arms and legs in dryland tests. Results: Muscle mass of arms and trunk moderately and strongly (r = 0.44–0.64) influenced the force generated by arms in tethered swimming. There was no significance in the relationship of leg muscle mass and force generated by legs in tethered swimming. Significant relationships were observed between the results of the 100-m front crawl and the muscle mass of the arms, trunk, legs, as well as the average work and maximal power in the arm-cranking test (r: 0.39–0.54). The average impulse of arm force and maximal leg force in tethered swimming moderately and significantly correlated with 100-m swimming results. Conclusions: The study concludes the relevance of developing muscle mass balanced to the body size, which is involved in propulsion force production in sprint front crawl swimming.

16

Attaching mass to the upper arm can increase throw distance in a modified javelin throw

Linthorne Nicholas, Heys Martin, Reynolds Tomas, Eckardt Nils

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 2

55--67

EN

The effectiveness of the whip-like coordination in throwing might be influenced by the inertial properties of the athlete’s arm. This preliminary study investigated the acute effect of attaching mass to the upper arm on the distance achieved in a modified javelin throw. The aim was to identify the optimum upper arm mass that maximizes throw distance. Methods: Three well-trained adult male athletes performed maximum-effort throws with an 800-g javelin training ball. A wide range of masses (0–1.5 kg) were attached to the upper arm and a 2D video analysis was used to obtain measures of the projection variables for each attached mass. Results: All three athletes showed an effect of attached arm mass on throw distance, and with the optimum mass the athlete’s throw distance was increased by 2.2 m, 1.2 m, and 0 m (7%, 4%, and 0%), respectively. The optimum mass was specific to the athlete (0.6 kg, 0.2 kg, and 0 kg) and changes in throw distance were mostly due to changes in release velocity rather than changes in release angle or release height. The experimental results were broadly similar to those obtained using a simple 2D mathematical model of throwing. Conclusions: These results indicate that some javelin throwers might see an increase in throwing performance when a mass is attached to their upper arm. However, the relationship between upper arm mass and throwing performance should be investigated further with studies on more athletes, projectiles of different mass, and other throwing events.

17

Uwarunkowania biomechaniczne stawu skroniowo-żuchwowego pod kątem pomiaru przemieszczenia ruchu żuchwy

Jadczak Kamila, Białek Rafał, Wiśnios Michał, Kuchta Marek

Przegląd Elektrotechniczny

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2019

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R. 95, nr 2

88--91

PL

Poniższy artykuł opisuje budowę oraz biomechanikę stawu skroniowo-żuchwowego pod względem pomiarów przemieszczenia żuchwy względem czaszki. Jest to wstęp do opracowania metody pomiaru przemieszczeń żuchwy w ramach projektu POIR.04.01.02-00-0029/17, którego celem jest opracowanie trójwymiarowego modelu stawu skroniowo-żuchwowego w celu odwzorowania działania aparatu kostno-chrzęstnowięzadłowego na potrzeby protetyki, ortodoncji i chirurgii ortognatycznej.

EN

The following article describes the structure and biomechanics of the temporo-mandibular joint in terms of measurements of the mandibular dislocation relative to the skull. This is the introduction to the development of the method of measurement of mandibular movements as part of the project POIR.04.01.02-00-0029 / 17, whose aim is to develop a three-dimensional model of the temporomandibular joint to reproduce the operation of the osteochlear-ligament apparatus for the needs of prosthetics, orthodontics and orthognathic surgery.

18

Effects of X-ray on fibroblast mechanical properties

Heydarian Ashkan, Khorramymehr Siamak, Vasaghi-Gharamaleki Behnoosh

Journal of Theoretical and Applied Mechanics

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2019

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Vol. 57 nr 4

999--1008

EN

Concerning the widespread use of X-rays to detect various diseases, such as oral and dental ones, it is essential to study the effects of this radiation on living cells. From the past, genetic effects and cell death because of X-rays have been studied. In addition, the effect of this ionizing radiation on the mechanical properties of the cell and cytoskeleton has been studied, but different results have been obtained based on different models. In this study, post-culture gingival fibroblast cells were classified into two groups of control and radiation with Nano Magnetic Particles functionalized by folic acid. The cells of the radiation group were exposed to X-rays of 3 mGy·cm2 . The specimens were undergone static creep test by a magnetic tweezer. Spring and damper coefficients were obtained based on the viscoelastic solid modeling. The static and dynamic stiffness of the groups was also calculated. The maximum deformation was decreased after radiation from 0.049 ± 0.01 µm to 0.029 ± 0.01 µm and the static stiffness of the model was 1.6 times decreased. Also, the gel point frequency for the control group was 27 Hz and for the radiation group was 7.5 Hz. The results show that the static and dynamic stiffness of the cells decreases after radiation, and less deformation appears in the cells after irradiation. These changes can be due to the breakdown of membrane chemical bonds and activation of actin fibers after radiation.

19

Wpływ buta typu Walker z zegarem na zmianę parametrów kinematycznych w stawach kończyn dolnych w chodzie

Lann vel Lace Karol, Błażkiewicz MIchalina

Aktualne Problemy Biomechaniki

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2019

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z. 17

35--42

PL

Celem pracy jest określenie wpływu różnych ustawień ortezy typu Walker na zmianę kątów w stawach kończyn dolnych podczas chodu. W badaniach wzięło udział 10 zdrowych osób. Do badań czterech rodzajów chodu -jeden bez ortezy i trzy w różnych ustawieniach ortezy wykorzystano system Vicon. Udowodniono, że sposób ustawienia ortezy ma istotny wpływ na zmianę kątów w stawie kolanowym i biodrowym kończyny dolnej, na której jest noszona orteza. Bardzo korzystny jest brak wpływu ortezy na kinematykę kończyny wolnej od ortezy.

EN

The aim of the work is to determine the effect of various settings of Walker type orthosis on lower limb kinematics parameters during walking. 10 healthy people participated in the study. The Vicon system was used to test four types of the gait - one without an orthosis and three in different orthosis settings. It has been proven that the way the orthosis is positioned has a significant impact on changing the angles in the knee and hip joints of the lower limb, on which the orthosis is worn. The absence of the orthotic effect on the kinematics of the limb free from orthosis is very beneficial.

20

Ocena stabilności posturalnej podczas strzelania

Błażkiewicz Michalina, Kędziorek Justyna, Bańkowska Sylwia, Wit Andrzej

Aktualne Problemy Biomechaniki

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2019

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z. 17

5--10

PL

Celem pracy była ocena stabilności posturalnej podczas strzelenia z łuku. W badaniach wzięły udział dwie grupy: zawodowi łucznicy oraz amatorzy, tzn. osoby, które nigdy nie strzelały z łuku. Badania zostały przeprowadzone przy użyciu systemu Vicon i platform Kistler. Do obliczeń zostały eksportowane położenia środka masy ciała. Następnie została policzona długość drogi CoM w przestrzeni 3D oraz współczynniki entropii próbkowej. Wykazano, że długość drogi CoM w przestrzeni 3D jest istotnie (p = 0.0001) dłuższa u łuczników podobnie jak współczynnik entropii próbkowej wzdłuż osi pionowej (p = 0.0117).

EN

The aim of the work was to assess postural stability during archery. Two groups participated in the study: professional archers and amateurs, i.e. people who never shot a bow. The tests were carried out using the Vicon system and Kistler platforms. Body mass center positions were exported to calculations. Next, the CoM distance in 3D space and sample entropy coefficients were calculated. It was shown that the distance of the CoM path in 3D space is significantly (p = 0.0001) longer in archers, similarly as the sample entropy coefficient along the vertical axis (p = 0.0117).