O objetivo do presente estudo foi analisar as respostas cinemáticas e neuromusculares de diferentes saltos da patinação artística sobre rodas, com e sem patins, as respostas cinéticas dos mesmos saltos sem patins, e as respostas cinéticas e cinemáticas do countermovement jump (CMJ), drop jump (DJ) e squat jump (SJ), em patinadores de elite. Foram avaliados quatro patinadores de elite do Rio Grande do Sul, sendo estes uma mulher e um homem da categoria Junior e uma mulher e um homem da categoria Sênior. Os sujeitos participaram de três sessões: a primeira foi destinada à coleta das medidas antropométricas e à realização da contração isométrica voluntária máxima para normalização da eletromiografia, a segunda foi destinada à coleta das variáveis cinéticas, cinemáticas e neuromusculares sem patins, no laboratório, e a terceira foi destinada à coleta das variáveis neuromusculares e cinemáticas durante os saltos realizados com patins, no ginásio. Foram avaliados quatro saltos da patinação artística: Axel simples, Axel duplo, Mapes duplo e Mapes triplo. Os sujeitos executaram três saltos de cada tipo e foi selecionado aquele que estava melhor localizado dentro da zona de filmagem e que apresentou a melhor qualidade de execução. De acordo com os resultados, os patinadores homens foram mais potentes do que as mulheres durante os saltos verticais CMJ, DJ e SJ. Nos saltos da patinação os quatro atletas apresentaram maior impulso, potência máxima, altura e velocidade rotacional durante os saltos com mais rotações do que durante os saltos com menos rotações, enquanto a velocidade horizontal no take-off foi menor nos saltos com mais rotações. Na comparação entre os saltos Axel e Mapes, os patinadores demonstraram maior duração da propulsão no salto Axel do que no Mapes. Quanto à análise eletromiográfica, os músculos gastrocnêmio lateral, reto femoral, vasto lateral, bíceps femoral e glúteo máximo, apresentaram maior ativação durante os saltos com mais rotações, principalmente nas fases de propulsão e voo. Sugere-se que os resultados obtidos no presente estudo sejam considerados no planejamento de um treinamento específico, já que podem ser importantes para o desenvolvimento dos patinadores de elite, provavelmente sendo úteis também para os patinadores de outros níveis que almejam alcançar o nível internacional e obter sucesso em competições. / The aim of the present study was to analyze the kinematic and neuromuscular responses of different roller figure skating jumps, with and without skates, the kinetic responses of the same jumps without skates and the kinetic and kinematic responses of the countermovement jump (CMJ), drop jump (DJ) and squat jump (SJ), in elite skaters. Four elite skaters from Rio Grande do Sul were evaluated, including one Junior female, one Junior male, one Senior female and one Senior male. Each one took part in three experimental sessions: the first one was to collect the anthropometric data and to perform the maximum voluntary isometric contraction for electromyography normalization, the second one was to collect the kinetic, kinematic and neuromuscular variables, without skates, at the laboratory, and the third one was to collect the neuromuscular and kinematic variables during the jumps executed with skates, at the rink. Four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. Subjects executed three jumps of each type and one was selected for analysis based on the best recording area and on the overall quality of the jump. According to the results, male skaters were more powerful than female skaters during the vertical jumps CMJ, DJ and SJ. During the roller figure skating jumps, the four skaters demonstrated higher impulse, maximal power, height and rotational velocity during jumps with more rotations than during jumps with less rotation, while the horizontal velocity at take-off was lower in the jumps with more rotations. Comparing the Axel and Mapes jumps, the skaters demonstrated more duration at the propulsion phase in the Axel jump than in the Mapes. In regard to the electromyographic response, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation in the jumps with more rotations and mainly in the propulsion and flight phases. It is suggested that the results obtained in this study are considered in planning a specific training, since they may be important for the development of elite skaters, probably being also useful for skaters of other levels that aim to achieve the international level and succeed in competitions.

O objetivo desse estudo é: (a) verificar o efeito do desgaste do calçado na Força de Reação do Solo (FRS) e na distribuição de pressão plantar e (b) verificar a influência do desgaste em calçados de diferentes destinações de uso. Três sujeitos participaram desse estudo, usando cada um quatro calçados de corrida, sendo dois de treinamento (T1 e T2) e dois de competição (C1 e C2). Os calçados foram submetidos ao uso correspondente a 300km. As coletas de dados foram feitas, com o calçado novo e após 100, 200 e 300km de uso, utilizando o sistema Gaitway e o sistema F-Scan. Nos calçados novos, na FRS, a Taxa de Crescimento1 (TC1) foi significativamente maior no calçado C2, do que nos calçados C1 e T2. Na distribuição de pressão plantar, pequena diferença foi observada na Área total (AT) e nos picos de pressão, entre os calçados. Na influência do desgaste nos resultados de grupo, na FRS, o TC1 apresentou valores semelhantes entre as condições Novo e 300km, portanto o choque mecânico não se alterou. Na fase ativa da FRS, oscilações pequenas foram observadas e atribuídas a possíveis variações naturais do movimento, conforme descrito por SERRÃO (1999) e WINTER (1991). Na distribuição de pressão, a AT apresentou um aumento significativo da condição Novo, para as demais condições de uso. O aumento da área foi atribuído à possível compactação do calçado, sendo que essa alteração justificaria a crença de que o calçado novo precise ser amaciado. Entre os picos de pressão analisados, apenas o Pico de Pressão do Antepé (PPA) apresentou diminuição significativa nos valores, da condição Novo para os 300km. Observou-se que após o desgaste imposto, o estresse mecânico se manteve ou se apresentou menor que nas condições iniciais. Na análise da influência do desgaste nos diferentes calçados, para TC1, as diferenças que inicialmente eram significativas tornaram-se não significativas, a partir dos 200km, entre os calçados C1, C2 e T2. Os parâmetros da fase ativa foram pouco influenciados, porém influenciados de forma distinta pelo desgaste, nos calçados analisados. Na distribuição de pressão plantar, a área de contato foi influenciada de forma distinta em cada calçado. Nos picos de pressão plantar, grandes variações foram observadas, porém não atribuíveis ao desgaste promovido no calçado. Conclui-se que o desgaste, correspondente a 300km, pouco alterou o choque mecânico e o estresse mecânico nos calçados analisados. Por meio da destinação de uso, não é possível prever a resposta de calçados de treinamento e de competição ao indivíduo, nem supor que a durabilidade do calçado de competição seja menor do que a do calçado de treinamento / The objective of this study is: (a) to verify the effect of footwear usage on the Ground Reaction Force (GRF) and on the Plantar Pressure Distribution and (b) to verify the influence of usage in footwear of different destinations of use. Three subjects had participated of this study, each one received four running shoes, two of them are designated for training regimen (T1 and T2) and two of them for competition (C1 and C2). The footwears were used for 300km. The data collections were made in four different moments, with new footwear and after 100, 200 and 300km of use, using the Gaitway system and the F-Scan system. When footwear was new, the Loading Rate1 (LR1) was significantly higher in footwear C2, than in the footwears C1 and T2. Analyzing plantar pressure distribution, small differences were observed in the Total Contact Area (TCA) and in the peak of pressure, between the footwears. In the analysis of the different usage stages, the LR1 presented similar values between the conditions New and 300km, therefore the mechanical shock did not enhanced. In the active phase of the GRF, small oscillations were observed and attributed to the possible natural variations of the movement itself, as described before by SERRÃO (1999) and WINTER (1991). In pressure distribution, the TCA showed a significant increase from the New condition, for the other conditions of use. The increase of contact area was attributed to the possible compactation of the footwear?s material, if so this would justify the belief that the new footwear needs to be softened. Considering all peak pressure variables, only Forefoot Peak Pressure (FPP) presented significant reduction in its values, from the New condition for 300km. Therefore it could be assumed that after corresponding usage of 300km, the mechanical stress remained the same or decreased compared with the earlier conditions of use. The shoes of different destinations when analyzed through the conditions, showed that the differences for LR1 that initially were significant had become not significant, from 200km, between the footwear C1, C2 and T2. In the pressure peaks plantar, great variations had been observed, however not attributable to the usage. The conclusion is that usage, correspondent 300km, has little effect on mechanical shock and on mechanical stress on the footwear analyzed in this study. By means of the use destination, it is not possible to foresee the answer of footwear to the individual, nor to assume that the durability of the footwear are worse in competition shoes than in training shoes

O objetivo deste estudo foi determinar a influência das características de três tipos de mochila através de parâmetros biomecânicos e fisiológicos selecionados. Foram voluntários 49 carteiros (30±7 anos, 1,74±0,62 m e 72,6±11,8 kg), que utilizaram 3 tipos de mochilas: mochila lateral simples (MLS), mochila lateral com cinto pélvico (MLCP) e mochila dupla com cinto pélvico (MDCP). Os sujeitos andaram durante 10 minutos sobre esteira rolante Trotter instrumentada com duas plataformas de força de reação do solo Kistler, utilizando um analisador de gases que analisou os gases expirados. As variáveis cinéticas da locomoção apresentaram diferenças significativas entre as mochilas. As variáveis cinemáticas não mostraram diferenças significativas. A ventilação apresentou diferenças entre MLCP (23,2±5,4 L · min-1) e MLS (22,5±5,0 L · min-1) e MDCP (22,3±4,8 L · min-1) e o consumo de oxigênio apresentou diferenças entre MDCP (14,6±4,1 mL · kg-1 · min-1) e MLS (15,1±3,6 mL · kg-1 · min-1) e MLCP (15,2±4,3 mL · kg-1 · min-1). Os dados dinâmicos apontaram para benefícios do uso da MLS, e os dados fisiológicos apontaram para benefícios do uso da MDCP. Embora os dados tenham apresentado diferenças estatísticas, estas não foram de magnitudes representativas, assim, a MDCP parece induzir maior demanda metabólica e a MLS menor estresse físico. / The aim of this study was to determine the influence of the satchel construction characteristics in selected biomechanical and physiological parameters during the accomplishment of the locomotion of mailmen pedestrians. 49 mailmen had been voluntary (30±7 years, 1.74±0.62 m and 72.6±11.8 kg), which had used 3 types of satchels, simple lateral satchel (MLS), lateral satchel with pelvic belt (MLCP) and double satchel with pelvic belt (MDCP). The subjects had walked 10 minutes on Trotter treadmill instrumented with two Kistler force platforms, using a gas analyzer that made analyzes of the exhaled gases. Fy1 presented differences between MLS (1.35±0.10) and MLCP (1.37±0.11) and MDCP (1.37±0.10), like others FRS parameters. The step and strike lengths had not been sensible to the different satchels. The VE presented differences between MLCP (23.2±5.4 L · min-1) and MLS (22.5± 5.0 L · min-1) and MDCP (22.7±4.8 L · min-1) and the VO2, presented differences between MDCP (14.6± .1 mL · kg-1 · min-1) and MLS (15.1±3. 6 mL · kg-1 · min-1) and MLCP (15.2±4.3 mL · kg-1 · min-1). The dynamic data had pointed to benefits using MLS, but the physiological data had indicated to benefits using MDCP. Although the data have presented statistical differences, but these had not been representative magnitudes, thus, the MDCP seems to induce bigger metabolic demand and MLS the lesser physical stress.

Esta tese objetivou investigar as características biomecânicas da corrida com mínima proteção para a planta do pé, bem como o efeito do treinamento sob estas condições sobre o aparelho locomotor. Para isso, 3 experimentos foram realizados: o experimento 1 caracterizou a realização da corrida e o efeito do treinamento com os pés descalços sobre parâmetros biomecânicos da corrida; o experimento 2 testou o efeito da transição de 4 meses do calçado tradicional para o minimalista, manipulando-se o calçado esportivo; e o experimento 3 comparou indivíduos habituados ao uso do calçado com indivíduos habituados a movimentos em condições de mínima proteção. Uma esteira equipada com plataformas de força (Sistema Gaitway) e um eletromiógrafo (EMG 1000 Sistema Lynx) foram utilizados para a aquisição dos dados biomecânicos. Agudamente, os 3 experimentos mostraram interferência negativa da proteção plantar reduzida sobre parâmetros da força de reação do solo (FRS). Contudo, no experimento 1 observou-se possibilidade de menor ocorrência de primeiro pico da FRS em indivíduos habituados a movimentos com mínima proteção, significando sobrecarga externa reduzida. Os experimentos 1 e 2 evidenciam melhora do controle de sobrecarga externa em função de 4 meses de treinamento com mínima proteção, diminuindo em até 54,4% o choque mecânico. Conclui-se que, forma aguda e em indivíduos não adaptados, as condições de mínima proteção podem interferir negativamente no movimento e no controle das cargas externas, aumentando a sobrecarga imposta ao aparelho locomotor durante a corrida. Contudo, a experiência em mínima proteção, principalmente adotada de forma crônica e específica, influencia positivamente o gerenciamento das cargas mecânicas, melhorando o controle de choque e rendimento / This thesis aimed to investigate the biomechanical characteristics of running with minimal protection for the foot, as well as the training effects upon the human body under this condition. For that, three experiments were performed: experiment 1 compared individuals accustomed to the use of footwear with individuals accustomed to motor tasks in conditions of minimal protection; the second experiment characterized the running barefoot and the effects of 4-month training barefoot upon its biomechanical parameters; and experiment 3 tested the effects of 4-month transition from traditional running shoe to the minimalist shoe, only manipulating the footwear. A treadmill equipped with force platforms (System Gaitway) and an electromyography (EMG 1000 - Lynx System) were used to measure the biomechanical variables. Acutely, the 3 experiments showed negative interference of minimal protection upon parameters of the ground reaction force (GRF). However, the experiment 1 presented the possibility of lower first peak of GRF occurrence in the participants who are adapted to minimal protection condition, what means decreased external load. The experiments 2 and 3 showed improvements in the external forces control as a response to 4 months of adaptation in minimal protection running, what could decrease about 54,4% of mechanical stress. In conclusion, the minimal protection condition can negatively influence the movement and stress control in a acute way and in individuals who are not adapted to minimal protection condition, increasing the overload imposed to human body during running. However, the adaptation to minimal protection condition, mainly in a chronicle and specific way, exert a positive influence upon the management of mechanical loads, improving impact control and performance

Inledning: 70% av alla skador av det främre korsbandet (ACL) sker vid icke-kontakt-situationer. En låg kokontraktionsratio mellan hamstrings och quadriceps (H:Q) kan ses som en riskfaktor för ACL. Få studier är gjorda kring detta i samband med enbenslandningar på olika underlag. Syfte: Syftet med studien var att undersöka kokontraktionen mellan rektus femoris och biceps femoris samt ground reaction force (GRF) vid drop landing från 30 cm på stabilt respektive instabilt underlag. Metod: Tre män deltog i studien. Studien utfördes i ett rörelselabb där deltagarna utförde enbenslandningar på stabilt respektive instabilt underlag. Muskelaktivitet mättes med elektromyografi (EMG) i musklerna rektus femoris och biceps femoris. GRF mättes med kraftplatta. EMG-amplituden beräknades i relation till respektive deltagares maximum voluntary isometric contraction (MVIC). Medelvärde och standardavvikelse för respektive muskel, H:Q-kokontraktionsratio och högsta uppmätta GRF (N/kg) beräknades. Resultat: EMG visade en högre aktivitet i rektus femoris jämfört med biceps femoris vid landning på respektive underlag. På gruppnivå visade biceps femoris minskad aktivitet vid landning på instabilt underlag och H:Q-kokontraktionsration minskade. Högsta uppmätta GRF visade en tendens att minska vid landning på instabilt underlag. Konklusion: Den minskade aktiviteten i biceps femoris vid instabilt underlag var oväntad vilket eventuellt kan förklaras med det låga deltagarantalet, den interindividuella variationen och val av underlag. Mer forskning behövs med ett större urval för att få ett mer tillförlitligt resultat. Det vore även intressant att standardisera och mäta knäledsvinkeln och inkludera mer utmanande instabila underlag. Detta skulle kunna bidra till ökade kunskaper kring olika underlag vid preventions- och rehabiliteringsträning.

The prevalence of asymmetry in performance research has increased in recent years with mixed results. Much of the performance research has focused on unilateral jumping activities attempting to show relationships to other performance variables. However, bilateral ground reaction forces (bGRF) from jumps are more frequently assessed in athlete monitoring programs and the asymmetry from those jumps could be a simple addition to data already being collected. Research into bGRF asymmetries is lacking and no studies have addressed longitudinal changes. Additionally, research into the relationship of asymmetries to performance have infrequently used athletes. For these reasons, this dissertation will focus on bGRFs by assessing reliability, determining the relationship to performance, and tracking longitudinal changes among collegiate athletes. These data indicate that impulse has high absolute (ICC > 0.87) and relative (CV < 3.22) reliability values and should be the preferred metric for assessing jumping asymmetry. As well, a combination of the braking and propulsive phase above body mass has higher correlations (r = -0.25 to -0.49) to jumping performance compared to the propulsive phase alone (r = -0.09 to 0.26). Males and female soccer players have differing relationships with asymmetry as males had the greatest correlations between weighted countermovement jump (CMJ) asymmetry and weighted CMJ performance (r = -0.49), whereas females produced their greatest correlations with unweighted CMJs (r = -0.43). Additionally, all statistically significant correlations between asymmetry and performance were negative. Athletes with higher asymmetry values typically realize improvements over time without specific interventions, whereas athletes with lower values may not experience many fluctuations. Overall, asymmetry has negligible relationships to strength lev els (r = 0.30 to with strength training. 0.22) but seems to be associated with the improved motor coordination Indeed, athletes with higher asymmetry values involved even displayed trends of greater performance gains over time.

The purpose of this study was to determine the acute effects of heavy resistance exercise on agility performance in court-sport athletes. Five men (age: 20.6 ± 1.9 years; body mass: 79.36 ± 11.74 kg; body height: 1.93 ± 0.09 m) and five women (age 21.2 ± 2.7 years; body mass: 65.8 ± 10.18 kg; body height 1.77 ± 0.08 m) volunteered to participate in the present study. All subjects were NCAA Division II athletes who currently participated in tennis or basketball and all had previous resistance training experience of at least one year. In a counterbalanced design, agility performance during a 10 m shuttle test was assessed following either a dynamic warm-up (DW) or heavy resistance warm-up (HRW) protocol. The HRW protocol consisted of three sets of squats at 50, 60, and 90% of 1-RM. Agility performance was captured using an eight camera motion analysis system and the mechanical variables of stride length, stride frequency, stance time, flight time, average ground reaction force, as well as agility time were recorded. No significant differences were reported for the HRW and DW protocols for any of the mechanical variables (p>0.05), although there was a trend towards the HRW protocol producing faster agility times compared to the control protocol (p = 0.074). Based on the trend towards a significant effect, as well as individual results it is possible that HRW protocols could be used as an acute method to improve agility performance in some court-sport athletes.

The purpose of this study was to determine the acute effects of heavy resistance exercise on agility performance in court-sport athletes. Five men (age: 20.6 ± 1.9 years; body mass: 79.36 ± 11.74 kg; body height: 1.93 ± 0.09 m) and five women (age 21.2 ± 2.7 years; body mass: 65.8 ± 10.18 kg; body height 1.77 ± 0.08 m) volunteered to participate in the present study. All subjects were NCAA Division II athletes who currently participated in tennis or basketball and all had previous resistance training experience of at least one year. In a counterbalanced design, agility performance during a 10 m shuttle test was assessed following either a dynamic warm-up (DW) or heavy resistance warm-up (HRW) protocol. The HRW protocol consisted of three sets of squats at 50, 60, and 90% of 1-RM. Agility performance was captured using an eight camera motion analysis system and the mechanical variables of stride length, stride frequency, stance time, flight time, average ground reaction force, as well as agility time were recorded. No significant differences were reported for the HRW and DW protocols for any of the mechanical variables (p>0.05), although there was a trend towards the HRW protocol producing faster agility times compared to the control protocol (p = 0.074). Based on the trend towards a significant effect, as well as individual results it is possible that HRW protocols could be used as an acute method to improve agility performance in some court-sport athletes.

No description available.

The unprecedented growth in participation in collegiate athletics has been accompanied by an increase in injury burden. The complex and multifactorial nature of sports injuries highlights the importance of monitoring athletes prospectively using a novel and holistic biopsychosocial approach, as opposed to contemporary practices that silo these facets of health. Data collected over two competitive, basketball seasons were used in a principal component analysis (PCA) model with the following objectives: i) Determine if on-court, sensor-derived and force-plate-derived countermovement jump (CMJ) biomechanics were correlated, ii) determine the reliability of the biomechanical principal components (PCs) and psychological state metrics (e.g., self-reported pain, etc.) across five preseason weeks, iii) investigate whether biomechanical PCs were correlated with psychological state across a season, and iv) explore whether subject-specific meaningful fluctuations could be detected using minimum detectable change statistics. Weekly CMJ (force plates) and on-court data (inertial measurement units), as well as psychological state (questionnaire) data were collected on the women’s basketball team at McMaster University for two seasons. It was found that on-court and CMJ biomechanics were correlated both between and within systems (r = |0.10, 0.94|; p < 0.05), suggesting that PCA would be an effective method to summarize data. The derived PCs displayed excellent reliability (ICC > 0.9), while psychological state metrics displayed moderate-to-good reliability (ICC = 0.71 – 0.89). While many relationships (n = 27) were identified between biomechanical PCs and psychological state metrics, no overarching associations were identified at the group level. However, subject-specific relationships were identified in case-studies, highlighting the potential utility of “red-flagging” meaningful fluctuations from normative biomechanical and psychological patterns. Overall, this work demonstrates the potential of advanced analytical modeling to characterize components of student-athlete performance, health, and well-being, and the need for more tailored and patient-centered athletic monitoring practices. / Thesis / Master of Science (MSc)