Dissertations / Theses on the topic 'Thigh muscles'

Although traditional prevention and management strategies for hamstring injuries have focussed on optimising muscle strength, flexibility and endurance, incidence and/or recurrence rates of these injuries remains high. A theoretical framework was developed considering additional factors that increase the stabilising demand of the hamstrings. These factors included loss of related stability at the knee and lumbopelvic regions and extrinsic factors during functional and sporting activities. The aims of this research were to determine whether electromyographic (EMG) derived hamstrings, quadriceps and gluteal muscle activation patterns as well as isokinetic torque generation patterns could differentiate athletes who had incurred a hamstring injury from uninjured control athletes. It was hypothesised that the EMG activity of the injured participants would be decreased compared to uninjured control participants during maximal activities, but increased during weight bearing activities. The research included the identification of laboratory-based tasks relevant to the function of the hamstring muscles; test-retest reliability of EMG variables recorded during these tasks; and a comparative cross-sectional study of hamstring-injured (hamstring group, HG) and control athletes (control group, CG). Electromyographic activation patterns were determined during assessment of concentric and eccentric isokinetic strength of the thigh muscles, during transition from double- to single-leg stance, and forward lunging. Isokinetic and EMG onset and amplitude variables were compared both within- and between-groups. Despite no significant differences for peak torque, the HG injured limb generated lower average eccentric flexor torque towards the outer range of motion in comparison to the HG uninjured limb (P = 0.034) and the CG bilateral average (P = 0.025). Furthermore, the EMG root mean square (RMS) decrease from the start to the end range of the eccentric flexor contraction was greater for the HG injured limb hamstrings than the CG bilateral average. During the transition from double- to single-leg stance, the EMG onsets of the HG injured limb (biceps femoris [BF] P < 0.001, medial hamstrings [MH] P = 0.001), and the HG uninjured limb (BF P = 0.023, MH P = 0.011) were earlier in comparison to the CG bilateral average. The transition normalised EMG RMS was significantly higher for the HG injured side BF (P = 0.032), MH (P = 0.039) and vastus lateralis (VL, P = 0.037) in comparison to the CG bilateral average. During the forward lunge, no significant differences were observed within- and between-groups for the normalised EMG amplitude prior to and following initial foot contact. These results suggest that during maximal isokinetic eccentric flexor contractions, the average torque and EMG activity is decreased towards the lengthened position of the hamstring-injured limb. This may be due to structural changes or neurophysiological inhibitory mechanisms. During the static weight bearing task an earlier onset of the HG hamstring muscles was evident in comparison to controls. The hamstrings and the VL of the injured limbs were activated at greater normalised amplitude. The increased muscle activation in the hamstring-injured limbs during the support phase may indicate a greater demand towards stability of the kinetic chain or changes in proprioceptive function. Future research should consider the mechanisms and clinical implications underlying a loss of eccentric flexor torque towards the outer range of contraction, and investigate why increased activation of thigh muscles occurs during the static weight bearing task in hamstring-injured athletes.

Advances in magnetic resonance imaging (MRI) and analysis techniques have improved diagnosis and patient treatment pathways. Typically, image analysis requires substantial technical and medical expertise and MR images can su↵er from artefacts, echo and intensity inhomogeneity due to gradient pulse eddy currents and inherent e↵ects of pulse radiation on MRI radio frequency (RF) coils that complicates the analysis. Processing and analysing serial sections of MRI scans to measure tissue volume is an additional challenge as the shapes and the borders between neighbouring tissues change significantly by anatomical location. Medical imaging solutions are needed to avoid laborious manual segmentation of specified regions of interest (ROI) and operator errors. The work set out in this thesis has addressed this challenge with a specific focus on skeletal muscle segmentation of the thigh. The aim was to develop an MRI segmentation framework for the quadriceps muscles, femur and bone marrow. Four contributions of this research include: (1) the development of a semi-automatic segmentation framework for a single transverse-plane image; (2) automatic segmentation of a single transverseplane image; (3) the automatic segmentation of multiple contiguous transverse-plane images from a full MRI thigh scan; and (4) the use of deep learning for MRI thigh quadriceps segmentation. Novel image processing, statistical analysis and machine learning algorithms were developed for all solutions and they were compared against current gold-standard manual segmentation. Frameworks (1) and (3) require minimal input from the user to delineate the muscle border. Overall, the frameworks in (1), (2) and (3) o↵er very good output performance, with respective framework's mean segmentation accuracy by JSI and processing time of: (1) 0.95 and 17 sec; (2) 0.85 and 22 sec; and (3) 0.93 and 3 sec. For the framework in (4), the ImageNet trained model was customized by replacing the fully-connected layers in its architecture to convolutional layers (hence the name of Fully Convolutional Network (FCN)) and the pre-trained model was transferred for the ROI segmentation task. With the implementation of post-processing for image filtering and morphology to the segmented ROI, we have successfully accomplished a new benchmark for thigh MRI analysis. The mean accuracy and processing time with this framework are 0.9502 (by JSI ) and 0.117 sec per image, respectively.

Dissertation (Ph.D.)--Worcester Polytechnic Institute.
Keywords: active muscles, out-of-position, fracture mechanisms, impacts, KTH, dynamic ligament failure model. Includes bibliographical references (leaves 353-365).

Bol je subjektivno, neprijatno opažanje i osećaj. Čovek često oseća bol u delu tela kojije znatno udaljen od mesta nastanka bola. U istraživanju je primenjena transverzalnametoda, jednokratnog merenja. Ispitivanjem je obuhvaćeno 136 ispitanika, aktivnihfudbalera, starosti 18-35 (20.49±3.73) godina. Sva merenja su vršena od 2006. do2016.godine. Ispitanici su ispunili anketu o postojanju bola u leđima, pre samogpočetka testiranja, gde su intenzitet bolnosti subjektivno procenili Rolandovom skalombola). Celokupan uzorak je stratifikovan proporcionalnom tehnikom u pet grupa naosnovu subjektivnog osećaja bola u leđima. Multivarijantnom metodom varijanseutvrđivane su razlike na generalnom sistemu uzorkovanih varijabli, prilikom čega jeustanovljeno da postoji statistički značajna razlika između navedenih grupa ispitanikapodeljenih na osnovu subjektivnog osećaja bola u leđima u izokinetičkim varijablamakoje su uzete u obzir ovim istraživanjem dok su Univarijantnom analizom varijanseutvrđene razlike u pojedinačnim varijablama. Iz navedenih empirijskih saznanja irelevantnih podataka iz stručne literature dobija se uvid u faktore koji utiču na bolnostanje određene regije, disfunkciju i slabost pojedinih mišićnih grupa, uticaj pojedinihmišićnih grupa na druge, kao i poremećaj u kinetičkom lancu lokomotornog aparatakod fudbalera. Samo istraživanje ukazuju na značaj i potrebu da se standardizujuprotokoli i konstruišu odgovarajući algoritmi za komparativnu sistematizaciju varijablidobijenih specifičnim ispitivanjima izokinetičkom dinamometrijom kod ispitanika kojise bave timskim sportom sa loptom (fudbal, kosarka, rukomet i dr). Dobijeni podaciposlužiće jednim delom kao deo monitoringa sportskog treninga, kao i efekatarazličitih trenažnih protokola na parametre mišićne snage kod fudbalera. Sportskomedicinski značaj na polju testiranja parametara mišićne snage izokinetičkomdinamometrijom se ogleda u prevenciji sportskih povreda ili u brzoj i efikasnojdijagnostici i terapiji istih, što značajno utiče na ekonomski aspekt, s obzirom da jeprofesionalni sport postao visoko komercijalizovan.
Pain is a subjective, uncomfortable perception and feeling. Human often feelspain in the part of the body that is significantly away from the place of origin of pain.The transversal method was performed during study, with a one-time measurement.The study included 136 subjects, active players, ages 18-35 (20:49 ± 3.73) years. Allmeasurements were carried out from 2006 to 2016. Before the start of the test,examinee completed the survey on the existence of back pain, where the intensity ofthe pain was subjectively assessed according to Roland pain scale. The entire sample was stratified by proportional technique into five groups, based on the subjective experience of back pain. Multivariate variance method for detection of differences in the general system of sampled variables, during which it was established that there is a statistically significant difference between the groups of examinee, who were divided on the basis of subjective experience of back pain of the isokinetic variables that are taken into account in this study while the univariate analysis of variance determined differences in the individual variables. From the empirical findings above and relevant information from technical literature, an insight was obtained into the factors that influence the painful condition of a particular region, dysfunction and weakness of certain muscle groups, the impact of certain muscle groups on others, as well as the disruption in the kinetic chain of the locomotor apparatus. The research highlights the importance of and the need to standardize protocols and construct appropriate algorithms for comparative systematization of variables obtained by isokinetic dynamometry specific trials in subjects who are engaged in team sports with a ball (football, basketball, handball, etc.). The data will serve partially as part of the monitoring of sports training, as well as the effects of various parameters of training protocols on muscle strength in football. Sports and medical significance in the field of testing parameters with isokinetic muscle strength dynamometry is reflected in the prevention of sports injuries or in the quick and efficient diagnosis and treatment of the same, which significantly affects the economic aspect, considering that professional sport has become highly commercialized.

Résumé de l'étude in vitro. L'objectif de cette étude in vitro était de créer un fantôme avec la même architecture musculaire (fibre, aponévrose ...) et les mêmes propriétés mécaniques que le muscle en condition passive et active. Deux fantômes homogènes ont été fabriqués avec différentes concentrations de plastisol pour simuler les propriétés élastiques du muscle en condition passive (50% plastisol) et active (70% de plastisol). Pour cela, des fils en Téflon (d = 0,9 mm) ont été insérés dans la partie supérieure du fantôme (50%) pour représenter les fibres musculaires. De plus, une feuille en matière plastique (8 x 15 cm) a également été placée au milieu du fantôme pour imiter la structure de l'aponévrose. Ensuite, des tests ERM ont été effectués à 90 Hz avec deux stimulateurs pneumatiques de différentes formes (tube en silicone, membrane circulaire) pour analyser l'effet du type du stimulateur sur la propagation des ondes. La longueur d'onde a été mesurée à partir des images phase et les propriétés élastiques (module de cisaillement) ont été calculées. Les deux fantômes (50% et 70%) ont montré des propriétés élastiques similaires à celles du muscle à l’état passif (2,40 ± 0,18 kPa) et actif (6,24 ± 0,21 kPa). Le stimulateur en forme de tube a donné des valeurs plus élevées (environ 1,2 kPa à 1,53 kPa). L'analyse du comportement des ondes a révélé un glissement le long de la feuille plastique. Ce phénomène a aussi été observé in vivo le long de l’aponévrose. L'onde a également été sensible à la présence des fils en téflon car des coupures, des trous, ont été identifiés au cours de la propagation de l’onde. Une nouvelle méthode de post-traitement a été créée pour mesurer les paramètres G' et G" à partir de tests ERM réalisés à plusieurs fréquences (60, 80, 100 Hz) et en utilisant des modèles rhéologiques. Cette méthode a été testée sur un fantôme (50%) qui n’avait pas d’inclusion. Les résultats des mesures viscoélastiques (G', G") ont été validés avec la technique HFVS (Hyper-Fréquence viscoélastique Spectroscopy). Des valeurs similaires, G' et G’’, ont été obtenues avec les deux techniques. Ce dernier résultat valide la nouvelle méthode de post-traitement pour mesurer les propriétés viscoélastiques. Résumé de l'étude in vivo. L'objectif de cette étude in vivo a été de développer des protocoles ERM pour caractériser les propriétés élastiques (module de cisaillement) des neuf muscles de la cuisse. Ces tests ont été effectués à une seule fréquence (90 Hz). Différents modules de cisaillement ont été trouvés entre les muscles. Le gracilis a révélé des propriétés élastiques plus élevées que les autres muscles. Ces différentes élasticités peuvent être dues à différentes compositions physiologiques et architecturales entre les tissus. Ensuite, les propriétés viscoélastiques des muscles ischio (ST, SM, et la BC) et du muscle Gr ont été déterminées en appliquant la nouvelle méthode de post-traitement des données (précédemment validée sur le fantôme 50%) avec des tests ERM multi fréquences (70, 90 et 120 Hz) et en utilisant des modèles rhéologiques. Les résultats ont montré que deux modèles rhéologiques, Zener et springpot, peuvent être utilisés pour mesurer les propriétés viscoélastiques des muscles à l’état passif. De plus, des résultats similaires ont été trouvés entre G "/ G ', obtenus expérimentalement à 90 Hz, et la valeur α du modèle de springpot
Summary of the vitro studies. The objective of this in vitro study was to create a phantom witch the same muscle architecture (fiber, aponeurosis …) and mechanical properties of muscle in passive and active states. Two homogeneous phantoms were manufactured with different concentrations of plastisol to simulate the muscle elastic properties in passive (50% of plastisol) and active (70% of plastisol) muscle conditions. Moreover, teflon tubing pipes (D = 0.9 mm) were thread in the upper part of the phantom (50%) to represent the muscle fibers and a plastic sheet (8 x 15 cm) was also included in the middle of the phantom to mimic the aponeurosis structure. Subsequently, MRE tests were performed at 90Hz with two different pneumatic drivers, tube and round shapes, to analyze the effect of the type of driver on the wave propagation. The wavelength was measured from the phase images and the elastic properties (shear modulus) were calculated. Both phantoms revealed elastic properties which were in the same range as in vivo muscle in passive (2.40 ± 0.18 kPa) and active (6.24 ± 0.21 kPa) states. The impact of the type of driver showed higher values with the tube (range: 1.2 kPa to 1.53 kPa). The analysis of the wave behavior revealed a sliding along the plastic sheet as it was observed for in vivo muscle study. The wave was also sensitive to the presence of the fibers where gaps were identified. A new post processing method was established to measure G’ and G” from experimental multi frequencies (60, 80, 100 Hz) MRE (MMRE) tests and rheological models. This method was tested on the phantom (50%) made without fiber. Cross validation of the viscoelastic (G’, G”) results was made with Hyper-Frequency Viscoelastic Spectroscopy (HFVS). Both techniques showed similar range of values for G’ and G” at the same frequencies. This last result validated our new data processing for the viscoelastic measurement. Summary of the in vivo studies. The objective of this in vivo study was to develop MRE protocols to characterize the elastic properties (shear modulus) of the nine thigh muscles. These tests were performed at a single frequency (90Hz). Different shear moduli were found between the muscles. The gracilis revealed the highest elastic properties compared to all the other muscles. These different elasticities may be due to different physiological and architectural compositions between the tissues. Then the viscoelastic properties of the ischio (ST, SM, and BC) and Gr muscles were determined based on our new data-processing method (validated on the phantom 50%) using MMRE tests (70, 90 and 120Hz) and rheological models. The results revealed that two rheological models, zener and springpot, can be used to measure the viscoelastic properties in passive state. A similar trend was found between the experimental ratios G”/G’ obtained at 90 Hz and the α value of the springpot model. The present MRE muscle protocol, and the viscoelastic data base, could be used as non-invasive diagnostic tools to evaluate tissue alterations, the progression of diseases, and the effect of treatments, such as the ongoing therapeutic trials for Duchenne muscular dystrophy

Sprint performance is one of the most highly prized faculties in the vast majority of sports, from short accelerations seen in team sports to high maximal speeds reached in track and field events. The capacity to accelerate rapidly and to reach very high speeds is an extremely desirable quality across the sports world. Although many factors influence sprint performance, the ability to produce high horizontal ground reaction forces (GRFs) throughout the sprint seems the ultimate determinant. This ability is inclusive of mechanical properties of the muscles, morphological features and neural mechanisms as well as the ability of the given athlete to orient horizontal GRFs. Moreover, it is known that muscle volume (MV) is closely' related to the ability to produce force and power in any given muscle, therefore, it is logical to suppose that larger muscles would be advantageous for sprint performance. However, enlargement of a muscle increases inertia in the segment and reduces angular acceleration and velocity, which is counterproductive for the goal of improving sprint performance. Thus, the aim of this thesis was to analyse the influence of thigh muscularity (quadriceps, hamstrings and adductors) in sprint performance by examining different populations with different levels of sprint performance and to study the adaptation of these muscles during sprint-training periods in national-level sprinters. In the first study (Study I), we analysed and compared thigh MVs, sprint performance and sprint mechanical properties (SMPs) from recreationally trained young men and male sprinters. Results from this study showed that sprinters accelerated better than trained males (ES = 2.12-3.68, P < 0.01), but more importantly, they were much faster at high speeds (ES= 4.53, P < 0.01). Sprinters also had larger thigh muscle volumes (ES = 1.12-2.11, P < 0.01), especially in the hamstring musculature. Moreover, strong correlations were found between hamstrings MV and sprint performance (r = -0.670, P < 0.01), and moderate correlations between adductors MVand sprint performance (r = -0.563, P < 0.05). Based on differences in thigh muscularity between these groups and the correlations found, we concluded that hamstrings muscularity plays an important role in sprint performance. Through the second study (Study II) we compared thigh muscularity, SMPs and performance between sprinters of both sexes. The analysis revealed that only normalised hamstrings MV differed between the sexes, being larger in males (ES = 1.26, P < 0.05), while quadriceps and adductors showed no differences. Males were much faster than females (ES = 5.01-6.68, P < 0.001) and exhibited greater SMPs (ES = 1.98-6.97, P < 0.01), especially at maximal velocity. As in Study I, strong correlations were found between hamstrings MV and sprint performance (r = -0.685, P < 0.01), and moderate between adductors MV and performance (r = -0.530, P < 0.05). Moreover, hamstrings muscularity was related to maximal velocity and not to maximal horizontal force, while adductors muscularity showed the opposite correlations. We concluded that hamstrings muscularity is more important than adductors muscularity in determining performance in sprinting. Moreover, hamstrings MV seems more important for reaching very high speeds than adductors MV. Finally, in the third study (Study Ill) we examined the effect of a 5-month sprint­ based training macrocycle (SBTM) on sprint performance, thigh MVs and SMPs of national-level sprinters. The athletes were tested before, during and after the SBTM. Sprinters improved their sprint performance in all distances analysed (ES = 0.46-1.11, P < 0.01) as well as improving maximal velocity (ES= 0.40, P < 0.01) and the ability to produce horizontal GRFs throughout the sprint (ES = 0.91, P < 0.01). Moreover, we observed a highly consistent hypertrophic pattern in quadriceps, hamstrings and adductors, with increases during the first half of the period of training and maintenance during the second half. Hamstrings and adductors increases were almost the same, and double that of quadriceps. The greater increase in hamstrings and adductors might be related to the prominent role of these muscle groups during sprinting.
La capacitat d'esprintar es una de les qualitats més apreciades en la majoria d'esports, des de les curtes acceleracions típiques d'esports col·lectius a les extremes velocitats màximes de curses de velocitat de l'atletisme. La capacitat d'accelerar ràpidament i aconseguir velocitats molt altes sempre és una qualitat molt desitjada dins el món de l'esport. Tot i que molts factors influencien el rendiment en l'esprint, sembla que la capacitat de produir grans forces horitzontals durant l'esprint és el determinant més important. Aquesta capacitat inclou propietats mecaniques dels músculs, factors d'arquitectura i morfologia muscular, propietats del sistema nerviós, com també l'habilitat de l'atleta per orientar endavant aquestes forces. D'altra banda, és sabut que el volum muscular (MV) està estretament lligat a la capacitat de produir força i potència d'un múscul, llavors, sembla lògic pensar que músculs més grossos suposaran un avantatge per al rendiment en l'esprint. Malgrat això, l'engrandiment d'un múscul implica un augment del seu moment d'inèrcia, i així mateix, una reducció de l'acceleració i velocitat angular del segment, la qual cosa és contraproduent per al bon rendiment en l'esprint. Així, l'objectiu de la tesi va ser analitzar la influència del desenvolupament dels grups musculars de la cuixa (quadriceps, isquiosurals i adductors) sobre el rendiment en esprint, analitzant diferents poblacions amb diferent nivell de rendiment, així com estudiar l'adaptació d'aquests grups musculars a un període d'entrenament d'esprint en velocistes de nivell nacional. En el primer estudi (Estudi I), vam analitzar i comparar els MVs de la cuixa, les propietats mecàniques de l'esprint (SMPs) i el rendiment en un grup d'homes joves actius i entrenats i un grup d'homes velocistes. Els resultats d'aquest estudi van mostrar que els velocistes acceleraven molt millor que els actius (ES = 2,12- 3,68; P < 0,01), però, sobretot, van ser molt més ràpids a velocitats altes (ES = 4 ,53; P < 0,01). Els velocistes també van mostrar tenir els músculs de la cuixa més grossos que els actius (ES = 1,12-2,11; P < 0,01), especialment els isquiosurals. A més, es van trobar fortes correlacions entre l'MV dels isquiosurals i el rendiment (r = -0,670; P < 0,01) i moderades entre l'MV dels adductors i el rendiment (r = -0,530; P < 0,05). Basant-nos en les diferències entre MVs entre grups, es va concloure que l'MV dels isquiosurals juga un paper important en el rendiment en l'esprint. En el segon estudi (Estudi II) vam comparar MVs de la cuixa, SMPs i rendiment entre velocistes de diferents sexes. Els resultats revelaren que només l'MV dels isquiosurals diferia entre sexes, essent més gran en els homes (ES = 1,26; P < 0,05), mentre que el de quadriceps i adductors no presentaven diferencies. Els homes van ser molt més rapids que les dones (ES = 5,01-6,68; P < 0,001) i mostraren SPMs molt superiors (ES = 1,98-6,97; P < 0,01), especialment la velocitat màxima. lgual que en el primer estudi, es van trobar fortes correlacions entre l'MV dels isquiosurals i el rendiment (r = -0,685; P < 0,01) i moderades entre l'MV dels adductors i el rendiment (r = -0,530; P < 0,05). A mes, l'MV dels isquiosurals va correlacionar amb la velocitat maxima i no ho va fer amb la força màxima horitzontal, mentre que l'MV dels adductors va mostrar correlacions oposades. Després de tot, vam concloure que el desenvolupament muscular dels isquiosurals sembla més important que el dels adductors de cara al rendiment en l'esprint. A mes, l'MV dels isquiosurals sembla més important que el dels adductors per aconseguir velocitats molt altes. Finalment, en el tercer i ultim estudi (Estudi Ill) vam analitzar l'efecte d'un període d'entrenament específic d'esprint (SBTM) de 5 mesos sobre el rendiment, els MVs de la cuixa i les SMPs en velocistes de nivell nacional. Els atletes van ser sotmesos a tests abans, durant i després de l'SBTM. Els resultats mostren que els velocistes van millorar el rendiment en totes les distàncies analitzades (ES= 0,46-1,11; P < 0,01), juntament amb una millora de la velocitat màxima (ES = 0,40; P < 0,01) i un increment de la producció de forces horitzontals durant l'esprint (ES = 0,91; P < 0,01). A mes vam observar un patró hipertròfic molt consistent en quadriceps, isquiosurals i adductors, amb increments en l'MV durant la primera meitat del període i manteniment durant la segona meitat. També vam veure que !'augment en l'MV d'isquiosurals i adductors va ser pràcticament igual, i fou el doble que el dels quadriceps. Aquest increment tan gran en isquiosurals i adductors, comparat amb els quadriceps, podria estar relacionat amb el rol que tenen aquests grups musculars en el rendiment en l'esprint.

La compréhension du comportement musculaire est un champ d'investigation primordial dans divers domaines tels que le sport, le crash automobile et la médecine. Peu de techniques in vivo permettent aujourd'hui de caractériser les propriétés mécaniques du muscle. Aussi, l'objectif de ce travail est de développer une méthode d'identification in vivo à partir demesures de champs de déplacement. La méthode d'identification est composée de 3 étapes interdépendantes. La première consiste à réaliser une IRM de la cuisse pour segmenter manuellement différents tissus musculaires (quadriceps, ischios, gracilis et sartorius) et le tissu adipeux. Un comportement Néo-Hookéen est choisi pour modéliser le comportement hyperélastique (C10, D). Dans un second temps, un dispositif expérimental de compression est développé pour mesurer le champ de déplacement in vivo à partir des techniques d'imagerie échographique et de Corrélation d'Images Numériques. Finalement, une méthode inverse est mise en œuvre pour identifier les paramètres C10 et D de chaque tissu. Par le biais d'un exemple numérique, l'erreur sur les paramètres identifiés est évaluée. Les cartographies des champs de déplacement expérimentaux confirment les observations qualitatives obtenues sur les images échographiques et sont validées par les champs de déformation obtenus par approximation diffuse. Une faible erreur d'identification (C10<3%, D<7%) est obtenue à partir de l'exemple numérique, et les paramètres mécaniques identifiés sont en accord avec la littérature. Ces résultats valident la démarche inverse mise en œuvre qui permettra, à terme, de suivre l'évolution des pathologies et de mener des simulations prédictives.

Thesis (M. Ed.)--Bowling Green State University, 2005.
Includes bibliographical references (leaves 38-44). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Objective: The main purpose of this study was to investigate the effect of acute quadriceps pain, caused by delayed onset muscle soreness (DOMS), on long-term habitual muscle activity in knee extensors and flexors. A second purpose was to investigate the effect of DOMS on controlled muscle activation in the laboratory, and to compare this with the habitual recordings. Methods: Eighteen healthy subjects (10 females and 8 males, mean age 23 years, range 20-31) participated in the study. Surface electromyography (sEMG) was recorded bilaterally from vastus lateralis, rectus femoris, vastus medialis and biceps femoris on two weekdays with one day of rest between recordings. The laboratory tests (standing, walking in stairs, standing up from a seated posture, isometric contraction, and maximal voluntary contraction [MVC]) were performed before the long-term field recordings. Body posture (sitting, standing, and walking) was recorded with an accelerometer, and heart rate was recorded with electrocardiography (ECG). Immediately after the first long-term recording, the subjects performed an eccentric exercise (Barbell lunges) with use of the dominant leg only. Pressure pain threshold (PPT), pain scored on visual analogue scale (VAS) and maximum force during a maximal isometric contraction were used to assess symptoms of DOMS. Results: There were no differences in time spent in different body postures or heart rate between the first and second long-term recording. DOMS was indicated by a significant reduction of PPT in the quadriceps muscle, a significant raised VAS-score, and a significant reduction in maximum knee extension force in the exercised leg. Habitual sEMG activity (median sEMG level, μV) of the antagonist in the exercised thigh increased from first to second long-term recording during seated posture, while sEMG activity in the exercised vastus medialis decreased from first to second long-term recording during periods with standing posture (P<.05 for both comparisons). Thigh sEMG activity remained unchanged for the untrained leg in all postures during the long-term recordings. During the laboratory tests, sEMG activity of the antagonist of the painful thigh increased during walking in stairs (P=.003), but remained unchanged in other controlled contractions. When comparing standing posture in the laboratory with standing posture during the long-term field recording, the same tendency was observed, i.e., decreased agonist and increased antagonist activity in the exercised leg. Conclusion: The present findings indicate that DOMS has no or only moderate effect on muscle activity, and the results indicates that the responses to muscle pain is not so stereotypical as suggested by the pain adaption model. Thus, the current findings support the notion that pain models should include a task dependency aspect. Key words: Delayed onset muscle soreness, electromyography, vastus lateralis, rectus femoris, vastus medialis, biceps femoris, posture, habitual activity patterns, vicious cycle theory, pain adaption model

Aim: The purpose of this study was to evaluate the relationship between weightlifting performance (snatch, clean and jerk, and total) and variables obtained from the isometric mid-thigh pull (IMTP). Methods: Twelve weightlifters, ranging from novice to advanced, performed the IMTP 10 days after a competition. Correlations were used to evaluate relationships between variables of the IMTP and absolute and scaled competition results. Results: Unscaled competition results correlated strongly with IRFD (0-200ms: r=0.567-0.645, 0-250ms: r=0.722-0.781) while results correlated weakly with Peak IRFD (5ms window, r=0.360-0.426). Absolute peak force values correlated very strongly with absolute values for the competition performance (r=0.830-0.838). Force at 100ms, 150ms, 200ms and 250ms also correlated strongly with competition results (r=0.643-0.647, r=0.605-0.636, r=0.714-0.732, r=0.801-0.804). Similar findings were noted for allometrically scaled values. Conclusion: Measures of average IRFD probably represent a more relevant variable to dynamic performance than does Peak IRFD (5ms). Maximum isometric strength also is likely to have a strong role in weightlifting performance.

Aim: The purpose of this study was: 1) to investigate the alterations and relationships among training variables, performance variables, and physiological variables and 2) investigate the effects of strength training on potentiation complexes. Methods: The study enrolled nine D-1 collegiate throwers and four control subjects. The throwers participated in an 11-week resistance training and throws program. Resistance training volume load and throwing volume were recorded for 11 weeks. Measurements of maximal strength (isometric mid-thigh pulls) and dynamic mid-thigh pulls (DMTP) across a spectrum of loads: Males- 60kg, 140kg, 180kg, 220kg, 140kg, 30% isometric peak force (IPF), Females- 60kg, 80kg, 100kg, 120kg, 80kg, 30% IPF), were measured at weeks 1, 7, and 11. The control group was tested for isometric maximum strength at T1 (week 1) and T3 (week 11) Results: The throwers increased at each time point in isometric peak force (IPF), allometrically scaled IPF (IPFa), and isometric impulse. The throwers strength (IPF and IPFa) was significantly greater than the controls and the throwers experienced statistically significant changes in maximum strength from T1 to T3 when compared to the controls. The throwers demonstrated statistically significant changes in total load variables (variable for load 1+ load 2 + load 3 etc.) for DMTPs. Conclusion: As a whole these data suggest a potential for increased performance capabilities specific to throwing. Some data trends indicate that potentiation can occur as a result of performing a heavy pull before a lighter one. However, increasing maximum strength as a result of focusing on strength training did not enhance this potentiation effect.

Background: Epidemiological findings indicate a higher risk of muscular thigh strain injury during the latter stages of both halves of soccer match-play, with muscular fatigue highlighted as a key etiological factor in injury causation. Anthropometric, biomechanical and physiological differences present in the Black African population may elicit unique thigh injury risk profiles, different from those of European and American players. Objectives: The purpose of the current research was to investigate the impact of soccer-specific fatigue on the risk of hamstring and quadricep injury in amateur Black African soccer players, in both the dominant and non-dominant legs. Methods: Participants were required to perform a soccer matchplay simulation (SAFT⁹⁰), consisting of multidirectional and utility movements, as well as frequent acceleration and deceleration. Selected physical, physiological and psychophysical responses were collected at specific time intervals throughout fatigue protocol performance. Results: Heart rate responses were observed to increase significantly (p<0.05) in response to the start of both halves, and remain elevated (but showing no further significant increase) during the performance of the remainder of the fatigue protocol. Significant (p<0.05) changes in both concentric and eccentric isokinetic variables of the knee flexors and extensors highlight the effect of muscular fatigue on performance in soccer match-play. Eccentric hamstring peak torque was observed to decrease significantly over time (60°.s⁻ₑ=17.34%, 180°.s⁻ₑ=18.27%), with significant reductions observed during both halves. The functional H:Q ratio at 180°.s⁻ₑ indicated a significant decrease over time (10.04%), with a significant decrease indicated during the second half of the SAFT⁹⁰ protocol. The passive half time interval did not result in significant changes in isokinetic variables. Isokinetic strength, work and power indicated no significant effects of leg dominance.. ‘Central’ and ‘Local’ ratings of exertion were observed to increase significantly (p<0.05) as a function of exercise duration. Conclusion: The overall reduction in both the eccentric hamstring peak torque and the functional strength ratio was illustrated to be similar to that of other soccer-specific fatigue research. As a result, the risk of thigh strain injuries is suggested to be similar regardless of playing level and race. These time dependent changes may have implications for competitive performance and increased predisposition to hamstring strain injuries during the latter stages of both halves of match-play

The influence that trunk and pelvis posture has on lower limb muscle activation in single leg stance is unknown. Normative surface EMG data on 8 hip and thigh muscles was collected in a single group containing 22 young asymptomatic males, monitored using the VICON motion analysis system. Paired clinically relevant test postures demonstrated changes in trunk position in the sagittal plane and pelvis position in the frontal plane had the greatest effect on muscle activation.

Repeat sprint ability has been investigated thoroughly, however optimal training methodology to improve RSA remains elusive. Both kinetic and physiological viewpoints have been used to scrutinize aspects of RSA including, initial sprint performance (anaerobic power), maximal cardiorespiratory fitness (VO2max), lactate threshold, anaerobic capacity (mean power), muscle activation (EMG), and local muscle oxygenation kinetics. To our knowledge no study has utilized maximal strength levels as a separate factor among a homogenous group of cardiorespiratory fitness individuals (as determined by peak VO2 during RSA). The purpose of this study was to better understand the relationship between maximal strength, muscular characteristics, and cycling RSA- respective to muscle oxygenation responses. Fifteen participants completed fifteen 10-second maximal effort sprints on a cycle ergometer interspersed with 30-seconds passive recovery. Respiratory, muscle oxygenation, and kinetic responses were monitored continuously and evaluated relationships with maximal strength and muscular architecture as determined by isometric mid-thigh pull and ultrasonography respectively. A series of 2 x 15 mixed design, group x time, ANOVA’s were used to evaluate the effects of group and or sprint on muscle oxygenation kinetics. Strong individuals were found to have significantly greater levels of muscle oxygenation usage, recovery and the respective rates; p = 0.01, p = 0.02, p

The purpose of this experiment was to investigate skeletal muscle blood flow and glucose uptake in m. biceps (BF) and m. quadriceps femoris (QF) 1) during recovery from high intensity cycle exercise, and 2) while wearing a compression short applying ~37 mmHg to the thigh muscles. Blood flow and glucose uptake were measured in the compressed and non-compressed leg of 6 healthy men by using positron emission tomography. At baseline blood flow in QF (P = 0.79) and BF (P = 0.90) did not differ between the compressed and the non-compressed leg. During recovery muscle blood flow was higher compared to baseline in both compressed (P<0.01) and non-compressed QF (P<0.001) but not in compressed (P = 0.41) and non-compressed BF (P = 0.05; effect size = 2.74). During recovery blood flow was lower in compressed QF (P<0.01) but not in BF (P = 0.26) compared to the non-compressed muscles. During baseline and recovery no differences in blood flow were detected between the superficial and deep parts of QF in both, compressed (baseline P = 0.79; recovery P = 0.68) and non-compressed leg (baseline P = 0.64; recovery P = 0.06). During recovery glucose uptake was higher in QF compared to BF in both conditions (P<0.01) with no difference between the compressed and non-compressed thigh. Glucose uptake was higher in the deep compared to the superficial parts of QF (compression leg P = 0.02). These results demonstrate that wearing compression shorts with ~37 mmHg of external pressure reduces blood flow both in the deep and superficial regions of muscle tissue during recovery from high intensity exercise but does not affect glucose uptake in BF and QF. © 2013 Sperlich et al.

:doi 10.1371/journal.pone.0060923

The purpose of this study was to investigate the kinetic and morphological adaptations that occur during distinct phases of a block periodized training cycle in weightlifters. Athlete monitoring data from nine experienced collegiate weightlifters was used. Isometric mid-thigh pull (IMTP) and ultrasonography (US) results were compared to examine the effects of three specific phases of a training cycle leading up to a competition. During the high volume strength-endurance phase (SE) small depressions in rate of force development (RFD) but statistically significant (p ≤ 0.05) increases in vastus lateralis cross-sectional area (CSA), and body mass (BM) were observed. The lower volume higher intensity strength-power phase (SP) caused RFD to rebound above pre-training cycle values despite statistically significant reductions in CSA. Small to moderate increases only in the earlier RFD time bands (<150 >ms) occurred during the peak/taper phase (PT) while CSA and BM were maintained. Changes in IMTP RFD and CSA from US reflected the expected adaptations of block periodized training phases. Changes in early (<100 >ms) and late (≥150 ms) RFD time bands may not occur proportionally throughout different training phases. Small increases in RFD and CSA can be expected in well-trained weightlifters throughout a single block periodized training cycle.

"Mammalian skeletal muscle is a very complicated biological structure to model due to its non-homogeneous and non-linear material properties as well as its complex geometry. Finite element discrete one-dimensional Hill-based elements are largely used to simulate muscles in both passive and active states. There are, however, several shortfalls to utilizing one-dimensional elements, such as the impossibility to represent muscle physical mass and complex lines of action. Additionally, the use of one-dimensional elements restricts muscle insertion sites to a limited number of nodes causing unrealistic loading distributions in the bones. The behavior of various finite element muscle models was investigated and compared to manually calculated muscle behavior. An improved finite element muscle model consisting of shell elements and Hill-based contractile truss elements in series and parallel was ultimately developed. The muscles of the thigh were then modeled and integrated into an existing 50th percentile musculo-skeletal model of the knee-thigh-hip complex. Impact simulations representing full frontal car crashes were then conducted on the model and the pre-loading effects from active thigh muscles on the femur were investigated and compared to cadaver sled test data. It was found that the active muscles produced a pre-load femoral axial force that acted to slightly stabilize the rate of stress intensification on critical stress areas on the femur. Additionally, the active muscles served to direct the distribution of stress to more concentrated areas on the femoral neck. Furthermore, the pre-load femoral axial force suggests that a higher percentage of injuries to the knee-thigh-hip complex may be due to the effects of active muscles on the femur. "

Tyrimo objektas: fantominio skausmo ir raumenų jėgos pokytis po kineziterapijos ir grįžtamojo ryšio. Tyrimo tikslas: įvertini kineziterapijos ir grįžtamojo ryšio poveikį fantominiams skausmams ir šlaunies raumenų jėgai po šlaunies amputacijos. Hipotezė: manome, kad taikant kineziterapiją ir grįžtamąjį ryšį po šlaunies amputacijos, fantominių skausmų intensyvumas sumažės ir šlaunies raumenų jėga padidės labiau, nei taikant kineziterapiją be grįžtamojo ryšio. Uždaviniai: 1. Palyginti fantominių skausmų intensyvumą ir šlaunies raumenų jėgą po šlaunies amputacijos kineziterapijos pradžioje ir po įprastinės be grįžtamojo ryšio kineziterapijos. 2. Palyginti fantominių skausmų intensyvumą ir šlaunies raumenų jėgą po šlaunies amputacijos kineziterapijos pradžioje ir po kineziterapijos kartu su grįžtamuoju ryšiu. 3. Palyginti įprastinės kineziterapijos ir kineziterapijos kartu su grįžtamuoju ryšiu poveikį fantominių skausmų intensyvumui ir šlaunies raumenų jėgai. Rezultatai: Tyrimo pradžioje, kontrolinės grupės tiriamieji fantominį skausmą įvertino 6,17±0,75, tiriamosios grupės tiriamieji – 6,83±0,75 balais. Tyrimo pabaigoje, kontrolinė grupė – 5,86±0,75, tiriamoji grupė – 5,17±0,75 balais. Prieš kineziterapiją kontrolinėje grupėje, po amputacijos, šlaunį tiesiančių raumenų jėga buvo 3,00±0,00, lenkiančių – 3,33±0,52, pritraukiančių – 2,83±0,51 ir atitraukiančių – 2,50±0,55 balų; tiriamojoje grupėje, šlaunį lenkiančių raumenų jėga buvo 3,17±0,47, tiesiančių – 3,00±0,00... [toliau žr. visą tekstą]
The object: effects of physiotherapy with mirror therapy for phantom pain and thigh muscle strength after transfemoral. The objective: the alteration of phant pain and thigh muscle after physiotherapy and mirror therapy. Hyptohesis: We consider, that the application of physiotherapy with mirror therapy helps to reduce phantom pain and improve muscle strenght better than physiotherapy without mirror therapy. The aims: 1. To compare phantom pain and muscle force in the beginning of physiotherapy and after physiothepy. 2. To compare phantom pain and muscle force in the beginning of physiotherapy and after physiotherapy with mirrot therapy. 3. To compare physiotherapy with mirror therapy and physiotherapy without mirror therpy for phantom pain and muscle force. Results: Beginning of the study, the control group subjects phantom pain score 6.17 ± 0.75, experimental group subjects - 6.83 ± 0.75 points. End of the study, the control group - 5.86 ± 0.75, experimental group - 5.17 ± 0.75 points. Before physical therapy in the control group after the amputation, the thigh muscle stretching force was 3.00 ± 0.00, flexion - 3.33 ± 0.52, attracting - 2.83 ± 0.51 and distracting - 2.50 ± 0.55 scores, the experimental group, the thigh, the muscle strength was 3.17 ± 0.47, stretching - 3.00±0.00, attracting - 2.67±0.47 and distracting-2.83±0.37 points. Application of physical therapy procedures, after 3 weeks, the control group, after the amputation, the thigh flexion strength was 4.33 ± 0... [to full text]

Made available in DSpace on 2014-07-29T15:25:13Z (GMT). No. of bitstreams: 1 TESE ANA LUIZA NETO JUNQUEIRA 2009.pdf: 346064 bytes, checksum: dd50393164905524036f6c970157aff8 (MD5) Previous issue date: 2009-08-13
This study is the first randomized controlled clinical trial for assessing the immunogenicity and reatogenicity of the Butang® vaccine in full term newborns, who were given the first vaccine dose within the first 12 hours of life, comparing two regions of application for the vaccine: anterolateral thigh (ALT) and ventrogluteal (VG). Butang® response was assessed in 224 newborns who were given the vaccine in the VG region and 250 in the ALT one. Both groups were similar regarding gender, weight, timing interval between doses of the vaccine and maternal characteristics. When comparing Butang® immunogenicity, we verified that the proportion of babies who developed anti-HBs protecting titres after three vaccine doses in the VG region was of 97.8% (IC 95%: 94.8 99.3) with geometric mean titer (GMT) of 427.5 mUI/mL (IC 95%: 344.9 530.0), similar to those who were given in the ALT region (97.6%; IC 95%: 94.8 99.1; GMT: 572.0 mUI/mL; IC 95%: 471.1 694.6), which provides evidence that this place is appropriate for hepatitis B vaccination. Eleven newborns did not respond to Butang®, being six of them vaccinated in the VG region and five in the ALT. The most of them were male, one factor which seems to interfere with hepatitis B vaccine response. We verified an increasing proportion of local reactions and fever according to the number of doses given. In addition, after the third dose the proportion of induration (4.0 vs. 11.4) was higher among babies who were given the vaccine in the ALT region when compared to those who were given in the VG region (p < 0,05). No association was observed concerning maternal anti-HBs titres and newborn vaccine response. The evidences of this study showed that the VG region is a safe and immunogenic site to hepatitis B vaccine administration in newborns.
Este estudo trata-se do primeiro ensaio clínico randomizado controlado, para avaliação da imunogenicidade e reatogenicidade da vacina Butang® em recém-nascidos a termo, que receberam a primeira dose da vacina nas primeiras doze horas de vida, comparando duas regiões de aplicação do imunógeno: ventro glútea (VG) e vasto lateral da coxa (VLC). A resposta à Butang® foi avaliada em 224 RN vacinados na região VG e 250 na VLC. Os dois grupos foram semelhantes quanto ao sexo, peso, intervalo de tempo entre as doses da vacina e características maternas. Ao comparar a imunogenicidade da Butang®, verificou-se que a proporção de crianças que desenvolveu títulos protetores de anti-HBs após a vacinação na região VG foi de 97,8% (IC 95%: 94,8-99,3) com média geométrica dos títulos (GMT) de anti-HBs de 427,5 mUI/mL (IC 95%: 344,9 530,0), sendo semelhante às vacinadas na região VLC (97,6%; IC 95%: 94,8 99,1; GMT: 572,0 mUI/mL; IC 95%: 471,1 694,6), evidenciando, portanto, esses locais como apropriados para a administração do imunógeno. Onze RN não responderam à Butang® com títulos protetores, sendo que cinco foram vacinados na região VG e seis na VLC. A maioria dessas crianças era do sexo masculino, um fator que parece interferir na resposta vacinal contra hepatite B. Em geral, observou-se uma proporção maior de reações locais e febre de acordo com o número de doses recebidas. Além disso, após a terceira dose da vacina, a proporção de enduração foi menor (4,0 vs. 11,4) em crianças vacinadas na região VG do que nas vacinadas na VLC (p < 0,05). Não foi observada qualquer associação entre títulos de anti-HBs maternos e resposta vacinal dos seus conceptos. As evidências deste estudo mostram que a região VG é um local seguro e imunogênico para a administração da vacina contra hepatite B em lactentes.

The aim of this investigation was to design and construct a prototype anthropomorphic thigh model which could assess the effectiveness of thigh protectors. This involved utilising data generated from living subjects and cadavers to select the soft tissue component of the model.

The increase in tissue extensibility and joint range of motion through stretching has often been demonstrated. However, the existence of an optimal stretch duration has not been proven and the identification of an ideal number of repetitions of a stretch has received little attention in the literature. The purpose of this study was to examine and clarify the relationship of duration and number of repetitions of a stretch and their effect on changes in hamstring extensibility (HE) resulting from a stretching program. The HE of 33 subjects who were randomly assigned to a control group or one of three treatment groups was assessed before and after a three-week stretching program. The subjects in the three treatment groups stretched once a day, five times a week, and either once for 15 seconds (1 X 15), twice for 15 seconds (2 X 15), or once for 30 seconds (1 X 30). A repeated measures ANOVA showed no statistically significant effect for treatment group (P=0.181) or for treatment by pre- and post-treatment measurements (P=0.140), but indicated a significant difference between pre- and post-treatment measurements (P<0.001). The HE of the control group (which did not stretch) changed only slightly (0.9��, SD 5.7), the 1 X 15 and 1 X 30 groups improved more clearly (4.2��, SD 3.1 and 3.8��, SD 6.7, respectively), and the 2 X 15 group's HE increased the most (6.8��, SD 3.9). The results suggest that varying durations and repetitions of a stretch may influence the magnitude of improvement of HE. However, with the relatively low power (0.46) in the present study, no statistically significant difference between stretching protocols of 1 X 15 seconds, 2 X 15 seconds, and 1 X 30 seconds could be found.
Graduation date: 1997

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2003.
Includes bibliographical references (leaves 207-212). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Background: No consistent findings have been reported regarding the relationship between aging muscle size and strength. This may be due to the use of an inaccurate method of muscle quantification, anatomical cross-sectional area, and a limited study of muscle group and contraction type. There is little normative data on thigh muscle size and strength, or the nature of relationships among muscle groups of the thigh in a healthy older population. Purpose: 1) To determine the relationship between muscle volume (MV) of the knee flexors, knee extensors, and hip abductors, and their associated muscle strength and fatigue. 2) To investigate the reliability and validity of stereology to determine MV, and to establish the reliability of a protocol to measure hamstring muscle fatigue. 3) To investigate thigh circumference, and determine whether or not it is representative of MV and/or strength. 4) To establish normative strength ratios for this population. Subjects: Healthy older males and females, 51-80 years old. Methods: MV was calculated from MRl’s of the subject’s legs, using stereology. lsokinetic and isometric strength was measured on the Kin-Com Dynamometer, and muscle fatigue was measured using EMG during an 80% maximum voluntary contraction (MVC). Thigh circumference was determined using a Lufkin steel tape measure. Results: Average MV was 1529.57 ± 500.54 cm³ for the quadriceps, 776.46 ± 231.65 cm³ for the adductors, and 613.59 ± 159.73 cm³ for the hamstrings. All three muscle groups showed a good to excellent relationship between MV and strength (r=0.76-0.91). Thigh circumference measures at 10 cm had a strong relationship with size (r=0.55-0.72) and strength (r=0.93) of all muscle groups. Isometric strength ratios were 0.41 for hamstring : quadriceps, and 0.37 for adductor : hamstrings, where MV ratios were 0.51 and 1.03 respectively. The hamstring : quadriceps endurance time ratio was 1.74. Conclusions: The reliability of using stereology to measure MV of the thigh muscles was established, showing strong relationships between thigh muscle size and strength. Muscle strength ratios, and the evidence supporting thigh circumference measures at proximal sites on the thigh to represent functional muscle groups, will assist therapists in the treatment of healthy older adults.
Medicine, Faculty of
Graduate

碩士
國立陽明大學
物理治療暨輔助科技學系
100
Background: Mountaineering and hiking have become a popular and common activity, but related researches in Taiwan focus mainly on physiological reactions much more than musculoskeletal system. However, the foreign experiments can’t transfer directly due to the unique forest environment in Taiwan, chronic mountaineering injuries and derivative benefits on specific physical performances wait for further study. Therefore, it is important to investigate the possible relation between mountaineering habit and musculoskeletal or knee cartilage changes. Purpose: This research compared the difference of sports injuries, body composition, thigh muscle function and femoral cartilage characteristics between different age groups and among different mountaineering experiences to explore the possible effects of mountaineering activities. Methods: This study was a cross-sectional, exploratory design. 84 healthy male were recruited, including 43 people with regular mountaineering habit, who divided into high-mountain group (HM) (55.6±4.27 y/o) and low-mountain group (LM) (57.2±3.4y/o), 21 age-matched men without exercise habit were allotted to no exercise group (NE) and the remainders were 21 young men in young group (YM) (57.2±3.4y/o). After signing a consent form, participants started to fill three questionnaires which were self-designed sports-related injuries questionnaire, WOMAC index and IPAQ short version, and then underwent physical examinations on body composition, knee flexors and extensors strength test, and footscan. Last procedure was ultrasound elastography evaluation over femoral cartilage. One-way ANOVA was employed to assess continuous data of four groups, differences before and after stress in four groups were examined with two-way repeated measures ANOVA, and multiple linear regression was used to identify the most significant prediction model for cartilage morphology. Statistical significant was set at P＜0.05. Results: HM presented the best knee strength compared with weakest performances in NE and was significant higher in right knee flexors. About femoral cartilage thickness, YM showed the thickest cartilage and significant better than NE, but didn’t obvious differ from HM and LM. The percentage of vigorous activity showed correlation with R’t quadriceps muscle quality (MQ) (r=0.38) and L’t quadriceps MQ (r= 0.33). The predict factors of femoral cartilage thickness were age, height, strength of knee flexors and extensor, quantity of vigorous activity, and mountaineering; the predict factors of femoral cartilage brightness were muscle mass percentage in lower extremity (LE), body weight (BW) and asymmetry index (ASI). Conclusions: Knee strength, activity quantity, mountaineering performance, muscle mass percentage in LE, BW and ASI were predict factors to cartilage morphology and which can be improved by acquired cultivation. Besides, no obvious femoral cartilage defects were discovered in mountaineering groups and a tendency of decreasing aging rate was found in knee strength and thickness. Therefore, mountaineering and hiking can probably be a recommended sport to middle-old aged men who without existing knee cartilage dysfunction.

Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Homoeopathy, Technikon Natal, 1997.
The purpose of this study was to investigate the effect of the administration of homoeopathic dilutions of phosphocreatine and glycogen on the anaerobic work capacity of humanthigh muscle. It was hypothesized that there would be an increase in the anaerobic work capacity after one week, and that this effect would persist for a further four weeks. The experimentwas performed according to the protocol of a double - blind clinical trial. The subjects were male caucasians between 17 and 23 years of age, all in good health for the duration of the test period. Sixteen subjects took doses of Phosphocreatine 4 CH and Glycogen 4 CH three times daily for 7 days (the experimental group). Twenty one different subjects took a placebo preparation at a similar dosage. The placebo preparation was 20 % ethanol in water, making it impossible to distinguish it by taste from the experimental preparation. Tests were performed on the Akron isokinetic tester. TIrree tests were performed by each subject: an initial test, and follow - up tests on days 7 and 35. The tests were in the form of explosive flexion and extension of the leg, with a maximum displacement of 195 degrees per second, for 30 seconds. The accumulated work done in flexion and extension was calculated. The subjects were instructed to continue in their normal lifestyle for the duration of the test period. Statistical analysiswas carried out, using the Wilcoxon signed - rank test to test for intra - group variation, and the Mann - Whitney U test to test for inter - group variation. Intra - group analysis of the variance revealed statistically significant increases in work done in the first and second follow - up tests for both the experimental and placebo groups. Inter - group analysis revealed that the groups were not statistically different in any of the parameters tested. Because the anaerobic work capacity increased in both the experimental and placebo groups, we conclude that the preparation was not the cause of the increase. We speculate that the increase could be due to psychological factors, such as differingresponses to motivation, and familiarity with the procedure in the follow - up tests, and physiological factors such as meals eaten or missed before the tests were performed.
M