Neuroplasticity provides the basis for many of our most fundamental processes including learning, memory and the recovery of function following injury. This thesis is concerned with the neurophysiological and functional correlates of sensorimotor neuroplasticity in the healthy and focal dystonic populations. My initial experiments were conducted to determine the functional correlates of neuroplasticity induced in the primary motor (M1) and primary sensory (S1) cortices during a grip lift task. In healthy subjects these experiments further quantified the role of M1 in the anticipatory control of grip force scaling and demonstrated a role for S1 in triggering subsequent phases of the motor plan. My second series of experiments served to extend these findings by examining the functional correlates of neuroplasticity induced in the supplementary motor area (SMA). This study provided evidence for the role of left SMA in the control of grip force scaling and a role for left and right SMA in the synchronization of grip force and load force during the grip-lift synergy. Afferent input is known to be a powerful driver of cortical reorganisation. In particular, the timing and pattern of afferent input is thought to be crucial to the induction of plastic change. In healthy subjects, I examined the neurophysiological effects of applying “associative” (synchronous) and “non-associative” (asynchronous) patterns of afferent input to the motor points or digits of the hand. I observed an increase in the volume and area of the cortical representation of stimulated muscles when associative stimulation was applied over the motor points of two hand muscles. This pattern of stimulation also caused the centres of gravity of the stimulated muscles to move closer together, mimicking the maladaptive changes seen in focal hand dystonia. Non-associative stimulation and stimulation applied to the digits did not produce such an effect. Task-specific focal dystonia is characterised by excessive representational plasticity resulting in cortical representations which are significantly larger, and demonstrate greater overlap, than those seen in healthy individuals. These changes are thought to be driven, in part, by repetitive movement patterns which promote associative patterns of afferent input over an extended time period. On the basis of this knowledge, I applied non-associative stimulation to the hand muscles of dystonic subjects. Following this intervention, I noted a contraction of representational maps and a separation in the centres of gravity of the stimulated muscles. These neurophysiological changes were accompanied by improvements on a cyclic drawing task. This thesis demonstrates the functional correlates of neuroplasticity in M1, S1 and SMA during object manipulation using a precision grasp. These findings further extend our knowledge on the mechanisms underlying effective grasp control and assist us in the development of future rehabilitation protocols for neurological conditions involving grasp dysfunction. In addition, this thesis is the first to demonstrate an improvement in both neurophysiological and functional measures in focal dystonia following a period of non-associative afferent stimulation. These results open up exciting new avenues for the development of effective treatment protocols in those with focal hand dystonia. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2010

La préhension manuelle est une des habilités de l’homme la plus développée et la plus utilisée dans la vie de tous les jours. Cette capacité nous permet de saisir et de manipuler des objets dans des configurations aussi nombreuses que complexes. Malheureusement, la main est aussi le siège de nombreuses blessures qui, de par l’importance de la préhension, sont fortement handicapantes. Face à ce constat, comprendre les contraintes mécaniques qui sont exercées dans les muscles, les tendons, les articulations et les ligaments lors de gestes de la vie quotidienne apparaît comme un enjeu majeur pour la prévention, la réhabilitation et l’ergonomie. L’objectif de ce travail doctoral était de développer un modèle biomécanique de la préhension permettant une estimation de ces variables non mesurables. A titre d’exemple,le paradigme de la pince pouce-index a été utilisé. Dans une première étude, les modèles biomécaniques de la pince disponibles dans la littérature ont été développés et comparés.Suite à cette évaluation, il a été constaté que ces modèles, en particulier le pouce,nécessitaient des améliorations pour permettre une évaluation physiologiquement réaliste lors de la préhension. Dès lors, plusieurs améliorations ont été proposées. Premièrement, une procédure expérimentale a été développée afin d’évaluer et d’inclure les participations mécaniques passives (ligaments, tissus mous, butées osseuses) de l'articulation trapèzométacarpienne. Deuxièmement, des mesures effectuées par IRM ont été utilisées afin d’intégrer l’action mécanique du muscle First Dorsale Interosseous dans l’équilibre du pouce,ce muscle étant alors négligé malgré son importance dans les tâches de préhension.Troisièmement, une méthode expérimentale permettant d’évaluer plus facilement et plus précisément, in situ, les axes de flexion/extension et d’adduction/abduction de l’articulation trapèzométacarpienne a été proposée et évaluée. Enfin, le modèle biomécanique incluant ces améliorations a été mis en œuvre dans une dernière étude ergonomique visant à étudier l’effet de la taille de l’objet manipulé sur les forces musculaires et articulaires. / Manual precision grip is one of man's most developed and most used ability in everyday lifeactivities. The negative outcome is the high exposure of the hand to repetitive stress injurieswhich are often very disabling. Thus, the understanding of the mechanical stress exerted inmuscles, tendons, joints and ligaments during gripping tasks appears as a major issue forinjury prevention, rehabilitation and ergonomic considerations. This doctoral work aimed atdeveloping a biomechanical model of the grip to estimate the unmeasurable internal loads. Asan example, the classical paradigm of the thumb - index finger grip was used. In a first study,the biomechanical models of the thumb available in the literature were compared and severalimprovements proposed in order to obtain more physiologically realistic predictions. First, anexperimental method was developed to evaluate and include passive structures moment intothe equilibrium of the trapeziometacarpal joint (TMC). Secondly, MRI was used to integratethe mechanical action of the First Dorsal Interosseous muscle at the TMC, since this musclehas commonly been neglected in thumb models but seems essential during pinch grip.Thirdly, the kinematic model which has to be used with the anthropometric data of tendonmoment arms was evaluated and compared to our proposition of a functional method toassess, in situ, the axes of rotation of the TMC. Finally, the biomechanical model includingthese improvements was implemented in an ergonomic study. We investigated the effect ofobject width on grip forces and muscles/joints loads. This doctoral work finds its consistencyin its desire to develop and apply the biomechanical modelling of the hand in the fields ofclinical and ergonomics.

Various aspects of performance (e.g., sprint speed, grip strength) are thought to be important determinants of the success of animals in natural activities such as foraging, mating, and escaping from predators. However, it is generally known that morphological properties enhancing one type of performance (e.g., speed) can lead to a reduction in another (e.g., strength). Such performance trade-offs have been quantified at the inter-specific level, but evidence at the inter-individual level remains equivocal. To test for the presence of a performance trade-off, I initiated a study on wild white-footed mice (Peromyscus leucopus). In summer 2016, I captured a total of 186 individuals, 87 of which were repeatedly phenotyped for grip strength and sprint speed. A significant positive relationship was found between body mass and grip strength (but not for sprint speed). Individual differences in performance were repeatable through time for both grip strength and sprint speed. Using a bivariate mixed model, I detected a significant negative correlation between grip strength and sprint speed at the among-individual level. By contrast, the within-individual correlation between grip strength and sprint speed tended to be positive, suggesting that some unquantified aspects of the mouse phenotype (e.g., body condition, age) may have a positive effect on both performance traits. Given the relatively low repeatability of grip strength and sprint speed, a failure to properly partition the correlation at the among- and within-individual level generates a counter-intuitive, positive correlation. This study is one the first to detect a performance trade-off at the among-individual level in a wild animal population.

A wide literature of predominantly behavioural experiments that use Stimulus Response Compatibility (SRC) have suggested that visual action information such as object affordance yields rapid and concurrent activation of visual and motor brain areas, but has rarely provided direct evidence for this proposition. This thesis examines some of the key claims from the affordance literature by applying electrophysiological measures to well established SRC procedures to determine the verities of the behavioural claims of rapid and automatic visuomotor activation evoked by viewing affording objects. The temporal sensitivity offered by the Lateralised Readiness Potential and by visual evoked potentials P1 and N1 made ideal candidates to assess the behavioural claims of rapid visuomotor activation by seen objects by examining the timecourse of neural activation elicited by viewing affording objects under various conditions. The experimental work in this thesis broadly confirms the claims of the behavioural literature however it also found a series of novel results that are not predicted by the behavioural literature due to limitations in reaction time measures. For example, while different classes of affordance have been shown to exert the same behavioural facilitation, electrophysiological measures reveal very different patterns of cortical activation for grip-type and lateralised affordances. These novel findings question the applicability of the label ‘visuomotor’ to grip-type affordance processing and suggest considerable revision to models of affordance. This thesis also offers a series of novel and surprising insights into the ability to dissociate afforded motor activity from behavioural output, into the relationship between affordance and early visual evoked potentials, and into affordance in the absence of the intention to act. Overall, this thesis provides detailed suggestions for considerable changes to current models of the neural activity underpinning object affordance.

Made available in DSpace on 2016-12-06T17:06:47Z (GMT). No. of bitstreams: 1 Marcio Fagundes Goethel.pdf: 1590838 bytes, checksum: 1839448bf478fedce4eed161ec9e8a38 (MD5) Previous issue date: 2012-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to analyze the characteristics of grip in Judo. The study included 08 athletes with a degree of black belt in Judo, male, over 18 years, competing at the international level and who seek to place the 2012 London Olympics. To characterize the types of grip that make up the judo technique to grab the opponent, there were shots of fighting athletes in training, was used a spreadsheet where identifies the type of grip on the judogi specific locations and also in relation to specific by hand. As for the quantification of the kind of grip on fighting, videos of international competitions were analyzed, was used a spreadsheet that quantifies the number of grips on each site judogi the opponent, so that later was made an indirect relationship with the spreadsheet data characterization and thus to obtain a quantification of the types of grip in international fights. For the measurement of handgrip dynamometers were used developed by Instrumentation Laboratory (LABIN/CEFID/UDESC). The handgrip strength was measured for 30 seconds, three times in the dominant hand and three times in the non dominant hand with measures interspersed in his hands, sitting, adapted from the American Society of Hand Therapists (ASHT). Was analyzed the following parameters of the Force vs. Time curve of the grip types identified, maximum force (FMAX), reaction time (TREACT), time to maximum force (TFMAX), growth rate of force (TXCRESC) and the Index fall of force (IQ). Among the results cited that were identified in all three ways to grip used by judokas: Full Palmar, digit-palmar and a third consisting of an association between Digit-palmar and lateral pinch. To check the difference in the use of forms of grip, between the dominant and non dominant hand was used Wilcoxon test where differences were found in the use of all forms of grip, in his hands. To see if there was a difference between the parameters of force-time curve of the ways to grip seen between the dominant and non dominant hand was used T test for paired data in the parametric data and Wilcoxon test for non-parametric, difference lying only in the Index fall of force of the Full palmar. To correlate the use of a way to grip with the behavior of their parameters from force-time curve was used Pearson's correlation test for parametric data and Spearman correlation test for non-parametric, and correlation was found in four cases. Two correlations were positive: use of Digit-palmar grip and the maximum force Full Palmar in the dominant hand and Full Palmar grip use and time to the maximum force in the non dominant hand. The other two correlations are presented as negative: Full Palmar grip use and maximum force Palmar grip in the dominant hand and the use of the association of Digit-palmar and lateral pinch and reaction time of lateral pinch grip on non dominant hand. The data obtained from the study demonstrate the difference function and use of the hands of judo, and how the usage is correlated with the parameters of force-time curve, explaining a specific conditioning. / O objetivo deste trabalho foi analisar as características da preensão manual no Judô. Participaram do estudo 08 praticantes de judô com graduação de faixa preta, do sexo masculino, maiores de 18 anos, que competem em nível internacional e que buscam vaga para a Olimpíada de Londres 2012. Para a caracterização dos tipos de preensão que compõem a pegada do Judô, foram realizadas filmagens dos atletas desempenhando pegadas no treinamento, utilizou-se uma planilha onde se identifica o tipo de preensão em locais específicos do judogui e com especificidade também em relação à mão. Já para a quantificação do tipo de preensão em lutas, vídeos de competições internacionais foram analisados, utilizou-se uma planilha que quantifica o número de pegas em cada local do judogui do adversário, para que posteriormente fosse realizada uma relação indireta com os dados da planilha de caracterização e assim obtivesse-se uma quantificação dos tipos de preensão em lutas internacionais. Para a mensuração da preensão manual foram utilizados dinamômetros desenvolvidos pelo Laboratório de Instrumentação (LABIN/CEFID/UDESC). A Força de preensão manual foi avaliada durante 30 segundos, três vezes na mão dominante e três vezes na mão não dominante com mediadas intercaladas entre as mãos, na posição sentada, adaptada da Sociedade Americana de Terapeutas da Mão (ASHT). Foram analisados os seguintes parâmetros da curva de Força x Tempo dos tipos de pega identificados, Força máxima (FMAX), Tempo de reação (TREACT), o Tempo até a força máxima (TFMAX), Taxa de crescimento da força (TXCRESC) e o Índice de queda da força (IQ). Entre os resultados cita-se que foram identificadas no total três formas de pega utilizadas pelos judocas: Palmar Plena, Dígito-palmar e uma terceira que consiste em uma associação entre Dígito-palmar e Pinça Lateral. Para verificar a diferença no uso das formas de pega, entre a mão dominante e não dominante foi utilizado o Teste de Wilcoxon onde foi encontrada diferença no uso de todas as formas de pega, entre as mãos. Para verificar se existia diferença entre os parâmetros da curva força x tempo das formas de pega identificadas entre a mão dominante e não dominante foi utilizado Teste T para dados pareados nos dados paramétricos e Teste de Wilcoxon para os não paramétricos, encontrando diferença somente no Índice de queda da força de preensão Palmar Plena. Para correlacionar o uso de uma forma de pega e o comportamento de seus respectivos parâmetros da curva força x tempo foi utilizado o Teste de Correlação de Pearson para os dados paramétricos e o Teste de Correlação de Spearman para os não paramétricos, sendo que foi encontrada correlação em quatro casos. Duas correlações obtiveram resultado positivo: uso de preensão Dígito-palmar e a força máxima Palmar Plena na mão dominante e o uso da preensão Palmar Plena e o tempo até a força máxima na mão não dominante. As outras duas correlações se apresentaram como negativas: uso da preensão Palmar Plena e a força máxima de preensão Palmar na mão dominante e uso da associação Dígito-palmar e Pinça Lateral e o tempo de reação da preensão de Pinça Lateral na mão não dominante. Os dados obtidos com a pesquisa demonstram a diferença de função e de utilização das mãos dos judocas, bem como de que forma a utilização se correlaciona com parâmetros da curva de força x tempo, explicando um condicionamento específico.

Made available in DSpace on 2016-12-06T17:07:24Z (GMT). No. of bitstreams: 1 Marcelo.pdf: 656486 bytes, checksum: f5d59d173920ae86c82f60ae88deaef7 (MD5) Previous issue date: 2010-03-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this study was to evaluate the parameters of the isometric handgrip strength curves in highly trained judo athletes from different categories. 44 judo athletes who were participating of the VII Troféu Brasil, which took place in Porto Alegre, RS and 25 Physical Education students participated of this study. The handgrip strength was evaluated using a dynamometer built at LABIN, located on CEFID/UDESC. The evaluation of the judo athletes was performed during the championship weighing, in Porto Alegre, and the evaluation of the students was performed at LABIN. The handgrip strength was evaluated for 10 seconds, with one attempt on the dominant hand and one attempt on the non dominant hand, on the seated position adapted from the ASHT. The parameters evaluated were Maximum force (FMAX), Time to maximum force (T100), impulse to maximum force (imp100), rate of decrease (IQ) and impulse (imparea1). For the analysis regarding the athletes, the individuals were divided into three groups, according to their body mass (MC), into two groups according to their results and into two groups according to T100. To eliminate the influence of MC over the strength values recorded on both tests and allow the comparison between individuals of different categories and consequently of different body sizes, the allometric scaling was performed on the FMAX. After the statistical analysis was conducted, differences between the lighter and heavier categories in the handgrip strength curve parameters were found. In this case, the correction of the strength values by the corrected MC eliminated the influence of the MC for the categories. Concerning the result of the competition, relative values highlighted the differences between the groups. It is suggested that further studies are conducted, investigating the handgrip strength in judo athletes, for a better understanding of the differences between he categories and a closer investigation to the sport. / O objetivo deste trabalho foi avaliar os parâmetros das curvas de força de preensão manual isométrica em judocas de alto nível competitivo e de diferentes categorias. Participaram do estudo 44 judocas participantes do VII Troféu Brasil, realizado em Porto Alegre, RS. Para a mensuração da preensão manual foi utilizado um dinamômetro de preensão manual desenvolvido no Laboratório de Instrumentação (LABIN), do Centro de Ciências da Saúde e do esporte (CEFID) da Universidade do Estado de Santa Catarina (UDESC). A avaliação dos judocas foi realizada durante a pesagem da competição, em Porto Alegre, e a dos estudantes foi realizada no LABIN. A preensão manual foi avaliada durante 10 segundos, uma vez na mão dominante e uma vez na mão não-dominante, na posição sentada, adaptada da Sociedade Americana de Terapeutas da Mão (ASHT). Foram analisadas a Força máxima (FMAX), o Tempo até a força máxima (T100), impulso até a força máxima (imp100); Índice de queda (IQ) e o impulso total (imparea1). Para as análises, os judocas foram divididos em três grupos de acordo com a massa corporal (MC), em dois grupos de acordo com o resultado na competição e para a análise em função do T100 em dois grupos. No intuito de eliminar a influência da MC sobre os valores de força registrados em ambos os testes e possibilitar a comparação entre indivíduos de diferentes categorias e conseqüentemente de diferentes tamanhos corporais, foi realizado o ajuste alométrico na FMAX pela MC1, MC0,67 e MC0,393. Depois de realizada a análise estatística, foram encontradas diferenças entre as categorias mais leves e as mais pesadas de judocas em parâmetros da curva de preensão tanto sem quanto com ajuste alométrico. O ajuste alométrico da força pela MC0,393 pareceu eliminar a influência da MC na força para judocas de diferentes categorias. Considerando o resultado da competição o MC0,393 evidenciou a diferença de força entre os grupos em valores ajustados, sendo os melhores colocados mais fortes tanto absoluta quanto relativamente. Sugere-se que mais estudos sejam realizados investigando a força de preensão manual em judocas, buscando um maior entendimento das diferenças apontadas entre as diferentes categorias e uma maior aproximação da prática do esporte.

O sistema antibloqueio de freios ABS (Antilock Braking System) é um dispositivo eletrônico-mecânico que complementa o sistema de freio tradicional e tem como objetivo fazer com que as rodas não travem na ocorrência de uma frenagem de emergência ou sob condições de alto perigo como superfície muito escorregadia, chuva forte ou gelo. Como resultado, o veiculo não perde a dirigibilidade fazendo com que o motorista consiga efetuar uma parada muito mais segura e, na maior parte dos casos, num espaço menor do que quando este sistema não se encontra a bordo do veiculo, mesmo que essa não seja a missão principal do ABS. Esta dissertação vai apresentar as diferenças que existem na frenagem de um mesmo bitrem, quando esse está equipado com diferentes tipos de ABS. O termo que vai determinar a \"qualidade\" da frenagem é a eficiência da mesma, ou seja, que percentagem de desaceleração máxima é atingida pelo binômio veículo-ABS numa frenagem em linha reta e pista seca e também com aderência diferenciada lado a lado. Para poder fazer essas estimações simulou-se o sistema de freios ABS com o software Matlab/Simulink. Foi desenvolvido um modelo em multicorpos introduzindo todas as características físicas e dinâmicas de um bitrem. Dados foram obtidos durante as simulações: velocidades, acelerações, forças verticais e tangenciais nas superfícies de contato das rodas, além da eficiência de frenagem. Uma característica fundamental dessa simulação tem sido o fato do bitrem ter dois semireboques ao invés de um só, o que faz com que o veículo combinado às vezes apresente um comportamento diferente do esperado. Foram simuladas as seguintes versões de ABS: 4s4m, 4s3m, 4s2m, 2s2m e 2s1m, sob condições de aderência simétrica e valor 0,6 e condições assimétricas com valores 0,6 e 0,2. No cavalo mecânico, o sistema ABS usado foi o mesmo ao longo da simulação, um 2s2m no eixo dianteiro e 4s4m no tandem. Com condições assimétricas de aderência, a ordem de eficiência dos sistemas foi: o 4s4m (menor distância de parada), depois foi o 4s2m e depois vieram o 4s3m, o 4s2m, o 2s2m e o 2s1m em último lugar. / The ABS braking system (Antilock Braking System) is an electronic-mechanical device which along with a conventional braking system is conceived to make the wheels don\'t lock in consequence of an emergency braking or dangerous road conditions such as slippery or icy asphalt or even heavy rain. As a result, car doesn\'t lose control and driver is enabled to perform a much safer stop. It could also require a shorter distance to a full stop although that is not the first purpose of ABS. This dissertation expects to spot the noticeable differences when a truck is stopped with different versions of the ABS. The \"quality\" of breaking is going to be set trough the braking efficiency parameter, i.e. a comparison between the deceleration reached and the maximum reachable by both truck and road conditions, over a straight path and both equal and different grip coefficient on the sides of the truck. The Matlab/Simulink software was used to simulate an ABS breaking system. A multibody model was developed including all physical and dynamical properties of a truck. Every single relevant data was displayed and monitored: velocity, acceleration, vertical and tangential forces on the common surface tire-ground, besides braking efficiency. One remarkable feature of the simulation was the fact that this modelled truck pulls two trailers, which can get to unusual or unexpected behaviour. Namely, the following ABS versions were tested: 4s4m, 4s3m, 4s2m, 2s2m and 2s1m, under symmetric grip of 0,6 and asymmetric grip values of 0,6 and 0,2. The tractor head used invariably a 2s2m on the front axle and 4s4m on the rear tandem. When it comes to asymmetric conditions the ABS versions were ranked this order: 4s4m, 4s2m, 4s3m, 2s2m and finally 2s1m.

Introduction: A complex interaction between muscles, tendons, bones, joints and nerves are required for optimal function of the human hand. It is known that an individual’s grip strength is vital for performance of physical demanding tasks such as strength training with free weights. Strength training including a thicker grip around the bar may enhance the strength of the grip in the athlete without other special routines for grip strength development. The purpose of this investigation was to examine the difference in performance in multiple repetitions in two strength training exercises using two different sizes on the bar, to look for correlations between grip strength of the subjects hand and the amount of repetitions executed with two different size of the bar and finally the correlation of hand size and the amount of repetitions executed with two different size of the bar. Method: 15 strength training men (23,9 ± 4,1 years), underwent measurements of hand size, maximum grip strength, 1 repetition maximum (1RM), a 80 % of 1RM weight strength test with two different  bar sizes. Results: The results from the present investigation indicates a 21,1 % reduction of 80 % of 1 RM weight performance in repetitions executed in the bench press with the thicker diameter of the bar and a 66,2 % reduction in repetitions executed with a 80 % of 1 RM weight in the lying bench row with the thicker diameter of the bar. The size of the hand or the maximum grip strength does not influences the performance in the 80 % of 1 RM strength test. Conclusion: With support of the results from this present investigation the size of the bar diameter significant influences the performance in maximum repetitions executed in a set in strength training with free weights, in a rowing exercise the repetitions executed reduced with 66,2 % and in the bench press the reduction of executed repetitions were 21,1 % with the thicker diameter of the bar. The size of the hand do not influences the performance of maximal executed repetitions with the thicker bar diameter. Maximal grip strength has no influence of the performance according to the findings of this investigation.

This report is a part of the research project "A New Model for Deformation of Carton Board Packages by Manual Handling". This project is a collaboration between Örebro University and two companies engaged in carton board packages. This report describes whether Syntouch's BioTac is an appropriate tool, compared with a consumer study when investigating the grip stiffness of consumer packaging. Syntouch's BioTac is an artificial sensor designed to imitate the force of a human fingertip. The concept of grip stiffness is used in the packaging industry to describe the packaging’s properties to withstand clamping pressure when handling by the user. That is, the robustness of the packaging. The carton board packaging should perceive as stiff, firm to grip and not deform during handling. The purpose is to perform laboratory tests with the BioTac sensor, to see if the sensor can be used as a measurement method for grip stiffness of card board materials. / Denna rapport som ingår i forskningsprojektet ”A New Model for Deformation of Carton Board Packages by Manual Handling”. Detta projekt är ett samarbete mellan Örebro Universitet och två företag som arbetar med förpackningar. I denna rapport beskrivs och analyseras om Syntouch’s BioTac är ett lämpligt verktyg, i jämförelse med en konsumentstudie vid undersökning av en förpacknings greppstyvhet. Syntouch’s BioTac är en konstgjord sensor som är utformad för att imitera kraften som en mänsklig fingertopp har. Greppstyvhet är ett begrepp som används i förpackningsindustrin och beskriver förpackningens egenskaper att kunna motstå klämtryck vid hantering. Det vill säga förpackningens robusthet. Förpackningen skall uppfattas som styv, greppvänlig och skall ej deformeras vid hantering. Syftet med det här arbetet är att utföra laborativa tester med sensorn BioTac, för att se om sensorn kan användas som en objektiv mätmetod för greppstyvhet för olika förpackningsmaterial.

A pilot study comparing the influence by different crease geometry on the grip stiffness of carton board packages has been executed. For this purpose, Syntouch Biotac, Lloyd LR5K tensiletester and crease measurements have been used. In total, 40 packages were manufactured and tested for this report. It was found that different crease geometries do have an effect on the difference in stiffness before and after collapse load. It was also found that vibration signals from Syntouch Biotac could be used to differentiate between different crease geometry at the instant of collapse load in the majority of cases. For continued work it is proposed that the same method used in this report should be applied on a larger number of packages. This is proposed so that a more thorough statistical analysis can be performed. It is also proposed, for continued work, that the interlaminar bonds between the plies of the carton boards be examined to gain a better understanding of the damage progress at the instant of collapse load. / En förstudie över fyra olika big-geometriers inverkan på greppstyvhet av kartongförpackningar har utförts. Syntouch Biotac, tryckprovare och bigmätningar har använts för ändamålet. Totalt har 40 kartongförpackningar tillverkats och testats för denna rapport. Det fanns att big-geometrier har en inverkan på skillnaden mellan styvhet innan och efter kollapslast av kartongförpackningen. Det fanns även att vibrationsutslag från Syntouch Biotac kunde skilja olika big-geometrier åt vid kollapslast i majoriteten av fall. Till fortsatt arbete föreslås att använda likadan metod på flera kartongförpackningar för att kunna utföra en nogrannare statistisk analys samt att undersöka styrkan hos de interlaminära bindningarna mellan kartongskikten för att bättre förstå skadeförloppet vid kollapslast.