Orientador: Fausto Bérzin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-21T20:25:06Z (GMT). No. of bitstreams: 1 CarranzaLopez_CarlosAlberto_M.pdf: 2138268 bytes, checksum: a9443199a187ae6526690dda5e8b63fe (MD5) Previous issue date: 2012 / Resumo: O osso hioide é um osso em forma de U que não se articula com nenhum outro osso, se localiza na parte anterior do pescoço e participa em funções importantes como deglutição, fala, mastigação e respiração. Para se manter estável, o osso hioide está suspenso por ligamentos, fascias e músculos. Diversos estudos em pessoas sem problemas dentários, esqueléticos nem funcionais demonstraram que o osso hioide localiza-se numa posição mais inferir nos homens que nas mulheres, mas nem sempre em todos os homens está nesta posição. O objetivo deste trabalho foi determinar se a posição do osso hioide tem relação com a atividade eletromiografica dos músculos supra-hioideos e infra-hioideos. Foram selecionados voluntariamente 16 homens classe I esquelética, sem problemas de disfunção temporomandibular, sem problemas visuais ou de respiração oral. Para avaliar a posição do osso hiode foram tomadas radiografias laterais em posição natural da cabeça de todos os voluntários e foi avaliado o triângulo hioideo. Para determinar a posição vertical do osso hióde, considerou-se a altura do triângulo hióide, valores menores a 3,4 mm foi considerado como posição superior do osso hioide (Grupo HS) e valores maiores a 4,6 mm como posição inferior do osso (Grupo HI). A atividade dos músculos supra-hioideos e infra-hioideos foi avaliada por meio da eletromiografia nas seguintes condições: repouso, isometria, protrusão, ápice da língua sobre o palato mole e deglutição. A comparação da raiz média quadrada (RMS) entre os grupos mostrou diferença significativa apenas para o movimento de protrusão. Este resultado poderia indicar uma maior sensibilidade dos fusos neuromusculares dos músculos supra-hioideos frente ao alongamento no grupo HS. Conclui-se que o os voluntários que tem o osso hioide numa posição superior apresentaram maior atividade dos músculos supra-hioide quando realizaram o movimento de protrusão / Abstract: The hyoid bone is a U-shaped bone and does not articulate with any other bone. He is located in front of the neck and participates in important functions such as swallowing, speaking, chewing and breathing. To remains stable, he is suspended by ligaments, fascia and muscles, as supra-hyoid and hyoid infra-hyoid muscles. Several studies in people without dental, skeletal or functional problems showed that hyoid bone is located in a lower position in men than in women, but not always he is in this position in all men. The aim of this study was to determine if the position of the hyoid bone interfere in electromyography activity of the supra hyoid and infra hyoid muscles. We selected voluntarily, 16 men skeletal Class I, without DTM, visual or mouth breathing problems. To assess the hyoid bone position were taken lateral radiographs of all volunteers and was assessed the hyoid triangle, too. To determine the vertical position of hyoid bone, it was considered the height of the hyoid triangle; values less than 3.4 was considered as upper position of the hyoid bone (Group UH) and values greater than 4.6 as lower position of the hyoid bone (Group LH). The activity of the supra hyoid and infra hyoid muscles were assessed by electromyography in following conditions: rest, isometrics, protrusion, tongue tip on the soft palate and swallowing. The comparison of the root mean square (RMS) between the groups showed a significant difference only for the movement of protrusion. This result could indicate a greater sensitivity of the neuromuscular spindles of supra hyoid muscles. We concluded that the volunteers that have upper position of hyoid bone showed higher activity of supra hyoid muscle when performed the protrusion movement / Mestrado / Anatomia / Mestre em Biologia Buco-Dental

M.Ing. / A great deal of work has been done in the field of hexapodous autonomous agents. However, in this dissertation the locomotion of a more complex organism - the octopod - will be studied. Biological neural behaviour will present a basis for the leg controllers, while classic backpropagation networks will be used to implement pattern generators. Full simulation of the biological scorpion leg will be implemented, thus a simulated leg consisting of six joint angles with 6 degrees of freedom. Simple locomotion on a flat substrate will be considered. In this dissertation the scorpion will be used as basis of simulation mainly due to the interesting leg architecture and intricate locomotory patterns during locomotion, hunting and burrowing. The locomotory models developed here may be modified to facilitate other terrestial octopodous agents.

The Sit-to-Stand (STS) transition is a voluntary daily activity that consists of rising from a sitting position to a standing position, an activity that is typically performed by a person several times a day. To undertake the activity successfully requires the coordination of the body limbs in order to transfer the body weight between the sitting and standing positions, maintaining the balance, in order to avoid a fall. A biomechanical analysis of the STS transition provides useful information about the motor ability and control strategy of a person and as such, it is commonly employed to assess functional performance, and as an indicator of lower limb strength in the elderly and in people with disabling diseases. The aim of the work described in this thesis was to investigate and analyse the STS transition in two groups of healthy subjects, a cohort (n=10) of younger adult participants (age range 28±2 years) and a cohort (n=10) of older adult participants (age range 56±8 years), in order to identify the differences in the performances within and between the two groups when the STS transition was undertaken at different speeds. The two groups of participants performed STS transition trials at three, different, self-selected speeds (normal, slow and fast) during which data was recorded from a caption systems, consisting of a set of six infrared-cameras and two force plates. The in-vivo data obtained was applied to a link segment biomechanical model enabling the kinematic contribution of the major body segments to the STS activity to be determined for each participant. A principal component analysis (PCA) was undertaken to identify any aggregate and segmental differences in the STS transition performance between speeds. In addition, a kinetic analysis was performed to determine the torque and power contributions of the lower limb joints during the STS transition. The results from the analysis showed that younger and older participants performed the STS transition with a similar pattern, but they used different strategies to ascend according to the speed at which the activity was being performed. The younger participants used the same strategy at slow speed than the older participants used at slow and normal speeds. Likewise, the younger participants used the same strategy at normal and fast speeds as the older participants used at fast speed. From the segmental analysis it was found that the upper-body and pelvis segments presented the larger variability than the other segments. From the joint analysis, the knee and hip joints were identified as the joints that provide the greatest contribution to the STS transition as they generated most of the power and torque required for the activity. The results obtained and the methodology developed could help clinicians with the diagnosis, planning and selection of treatment for patients with a lack of mobility. This type of analysis may also find application in fields such as robotics, ergonomics and sports training.

The eggbeater kick is a skill used frequently in water polo and synchronized swimming to elevate the upper body for shooting, passing, blocking or compete with the opponent for position in the water. The hips, knees, and ankles are involved in creating favourable orientations of the feet so that propulsive forces in the vertical direction can be created. Literature reporting the technique of the eggbeater kick is scarce and limited to description of kinematics or muscle activity. The relationship of the kinematics to the demands on specific muscles has not been established. The purpose of this study was to analyze the kinematics and muscle activity of the water polo eggbeater kick in fatigued and unfatigued states to provide foundational knowledge on which training programs can be based. Twelve water polo players were tested executing the eggbeater kick in the vertical position while trying to maintain as high a position as possible for the duration of the test. The test was terminated when the player could not keep the top of the sternum marker above water. Anthropometric data were collected using the ‘eZone’ method. Three dimensional coordinates for the lower limbs and two dimensional coordinates of the above water top of the sternum marker were obtained. Surface electromyography recorded the muscle activity of the Tibialis Anterior, Rectus Femoris and Biceps Femoris muscles on both legs. Differences between fatigued and unfatigued conditions and between dominant and nondominant sides were tested using a two factor ANOVA with repeated measures. Differences within subjects were also investigated on a subject by subject basis with regard to muscle activity. Results indicated differences for kinematic and muscle activity variables between fatigue levels. The amplitude of anatomic angles and speed of the feet decreased with fatigue. Significant differences were found between dominant and non-dominant sides for the ankle motion. The non-dominant ankle was more inverted and adducted than the dominant ankle during the knee flexion phase of the cycle. The Rectus Femoris muscle had consistent patterns across subjects, while Tibialis Anterior and Biceps Femoris muscles were more subject specific in their responses. The Rectus Femoris and the Biceps Femoris have an agonist/antagonist relationship during knee flexion and extension. The Tibialis Anterior was active for long periods in the cycle while dorsiflexing and inverting the foot. As a consequence activity in these muscles decreased with fatigue. These findings point towards the necessity for players and coaches to address specific motions and muscles during the training of the eggbeater technique. Future work should focus on developing eggbeater kick training programs that address specific strength and flexibility.

The incidence of restenosis has been shown to be correlated with the overstretching of the arterial wall during an angioplasty procedure. It has been proposed that slow balloon inflation results in lower intramural stresses, therefore minimizing vascular injury and restenosis rate. The analysis of the biomechanics of the arterial tissue might contribute to understand which factors trigger restenosis. However, few mechanical data are available on human arteries because of the difficulty of testing artery samples often obtained from autopsy while arteries are still considered "fresh". Various solutions mimicking the physiological environment have been used to preserve artery samples from harvesting to testing. In vitro mechanical testing is usually preferred since it is difficult to test arteries in vivo. Uniaxial and biaxial testing has been used to characterize anisotropic materials such as arteries, although methodological aspects are still debated. Several objectives were formulated and analyzed during the making of this thesis. In one study, the effect of deformation rate on the mechanical behavior of arterial tissue was investigated. The effect of several preservation methods, including cryopreservation, on the mechanical properties of porcine thoracic aortas was also analyzed. Finally, the differences in the mechanical behavior between three different types of sample geometry and boundary conditions were compared under uniaxial and equi-biaxial testing. Thoracic aortas were harvested within the day of death of pigs from a local slaughterhouse. Upon arrival, connective tissue was removed from the external wall of the artery. Then the artery was cut open along its length and cut out in rectangular samples for uniaxial testing, and square and cruciform samples for biaxial testing. Samples belonging to the freezing effect study were preserved for two months at -20°C and -80°C in isotonic saline solution, Krebs-Henseleit solution with 1.8 M dimethylsulfoxide, and dipped in liquid nitrogen. Samples belonging to the deformation rate effect study were tested uniaxially and equi-biaxially at deformation rates from 10 to 200 %/s. The uniaxial and biaxial experiments were simulated with the help of an inverse finite element software. The use of inverse modeling to fit the material properties by taking into account the non-uniform stress distribution was demonstrated. A rate-dependent isotropic hyperelastic constitutive equation, derived from the Mooney-Rivlin model, was fitted to the experimental results (i.e. deformation rate study). In the proposed model, one of the material parameters is a linear function of the deformation rate. Overall, inverse finite element simulations using the proposed constitutive relation accurately predict the mechanical properties of the arterial wall. In this thesis, it was found that easier attachment of samples (rectangular and cruciform) is accomplished using clamps rather than hooks. It was also found that the elastic behavior of arteries is nonlinear and non-isotropic when subjected to large deformations. Characterization of the arterial behavior at large deformations over a higherdeformation range was achieved using cruciform samples. The mechanical properties of arteries did not significantly change after preservation of arteries for two months. Under uniaxial and biaxial testing, loading forces were reduced up to 20% when the deformation rate was increased from 10 to 200 %/s, which is the opposite to the behaviour seen in other biological tissues. The differences observed in the mechanical behavior of fresh and thawed samples were not significant, independently of the storing medium or freezing temperature used. The lack of significant differences observed in the freezing study was likely due to the small number of samples tested per storing group. Further studies are required to clarify the impact of cryopreservation on extracellular matrix architecture to help tailor an optimized approach to preserve the mechanical properties of arteries. From the results obtained in the deformation rate study, it is concluded that the stiffness of arteries decreases with an increase in the deformation rate. In addition, the effect of deformation rate was observed to be higher than the effect of anisotropy. The inverse relationship between stiffness and deformation rate raises doubts on the hypothesized relationship between intramural stress, arterial injury, and restenosis. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

No description available.

With the popularity of outdoor activities like hiking, the demands of certain types of employment, or being a student, an individual’s ability to carry a load is an important mobility consideration. By understanding the changes to an individual’s gait when supporting a backpack load, an individual’s ability to carry heavy loads for prolonged periods could be improved. Most biomechanical studies have examined the changes in able-bodied gait when carrying a load. However, research is lacking on the effect of backpack loads on amputee gait patterns. This project examined the effects of a backpack load on the gait patterns of unilateral transtibial amputees. Ten participants performed walking trials on four surfaces (level ground, uneven ground, walking up an incline, and walking down an incline), without a pack and with a pack. A total of 40 trials were collected per subject, with 10 trials collected on each surface. Three-dimensional motion data were collected with an eight-camera Vicon Motion Analysis system to describe limb motion as well as compare kinematic outcomes between tasks and conditions. Force platform data were collected during the level ground trials and used to calculate kinetic measures for both limbs. With the addition of the pack changes were seen on each surface, with different changes occurring to each limb. The ramp up surface created the most changes when comparing the two conditions. The only change seen across all four surfaces was a decrease in ankle dorsiflexion before push-off on the prosthetic limb. The two next most common changes were increases in knee and hip flexion during weight-acceptance.

The varied impact parameters that characterize an impact to the head have shown to influence the resulting type and severity of outcome injury, both in terms of the dynamic response, and the corresponding deformation of neural tissue. Therefore, when determining head injury risks through event reconstruction, it is important to understand how individual impact characteristics influence these responses. The effect of inbound mass had not yet been documented in the literature. The purpose of this study was to determine the effects of inbound mass on the dynamic impact response and brain tissue deformation. A 50th percentile Hybrid III adult male head form was impacted using a simple pendulum system. Impacts to a centric and a non-centric impact location were performed with six varied inbound masses at a velocity of 4.0 m/s. The peak linear and peak angular accelerations were measured. A finite element model, (UCDBTM) was used to determine brain deformation, namely peak maximum principal strain and peak von Mises stress. Inbound mass produced significant differences for peak linear acceleration for centric (F(5, 24) = 217.55, p=.0005) and non-centric (F(5, 24) = 161.98, p=.0005), and for peak angular acceleration for centric (F(5, 24) = 52.51, p=.0005) and non-centric (F(5, 24) = 4.18, p=.007) impact locations. A change in inbound mass also had a significant effect on peak maximum principal strain for centric (F(5, 24) = 11.04, p=.0005) and non-centric (F(5, 24) = 5.87, p =.001), and for peak von Mises stress for centric (F(5, 24) = 24.01, p=.0005) and non-centric (F(5, 24) = 4.62, p=.004) impact locations. These results indicate the inbound mass of an impact should be of consideration when determining risks and prevention to head and brain injury.

Knee-ankle-foot orthoses (KAFOs) are full leg braces for individuals with knee extensor weakness, designed to support the person during weight bearing activities by preventing knee flexion. KAFOs typically result in an unnatural gait pattern and are primarily used for level ground walking. A novel variable resistance orthotic knee joint was designed and evaluated to address these limitations. This low profile design fits beneath normal clothing. Mechanical and biomechanical testing demonstrated that the design resisted knee motion during stance phase, released the knee joint without restricting the knee’s range of movement, and provided flexion resistance during stair descent. Design modifications and related testing procedures were developed to further improve joint performance and to validate the design prior to testing on individuals with knee extensor weakness.

Since the introduction of helmets the incidence of traumatic brain injuries (TBI) in ice hockey has greatly decreased, but the incidence of concussions has essentially remained unchanged. Despite goaltenders in ice hockey being the only players on the ice for the entire game, few have assessed the performance of ice hockey goaltender masks. In ice hockey, goaltenders are exposed to impacts from collisions, falls and projectiles. The objective of this study was to assess the protective capacity of ice hockey goaltender masks for three accident events associated with concussion. A helmeted and unhelmeted medium NOCSAE headform were tested under conditions representing three common accident events in ice hockey. Falls were reconstructed using a monorail drop. A pneumatic linear impactor was used to reconstruct collisions and projectile impacts were reconstructed using a pneumatic puck launcher. Three impact locations and three velocities were selected for each accident event based on video analysis of real world concussive events. Peak resultant linear acceleration, peak resultant rotational acceleration and rotational velocity of the headform were measured. The University College Dublin Brain Trauma Model (UCDBTM) was used to calculate maximum principal strain (MPS) and von Mises stress in the cerebrum. The results demonstrated the importance of assessing the protective capacity of ice hockey goaltenders masks for each accident, as each event created a unique response. A comparison of unhelmeted and helmeted impacts revealed ice hockey goaltender masks are effective at reducing the risk of both concussion and TBI for falls and projectiles, but less so for collisions. Further, the risk of more serious injuries was found to increase for falls and collisions as impact velocity increased. The results highlight the importance of impacting multiple locations when assessing the protective capacity of ice hockey goaltenders masks, as different impact locations result in unique responses. Overall this study demonstrated ice hockey goaltenders masks capacity to reduce the risk of concussion across three accident events.