185 research outputs found

    Morphology and Mechanical Properties of Plantar Fascia in Flexible Flatfoot: A Noninvasive In Vivo Study

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    From Frontiers via Jisc Publications RouterHistory: collection 2021, received 2021-06-20, accepted 2021-08-16, epub 2021-09-15Publication status: PublishedPlantar fascia plays an important role in human foot biomechanics; however, the morphology and mechanical properties of plantar fascia in patients with flexible flatfoot are unknown. In this study, 15 flexible flatfeet were studied, each plantar fascia was divided into 12 positions, and the morphologies and mechanical properties in the 12 positions were measured in vivo with B-mode ultrasound and shear wave elastography (SWE). Peak pressures under the first to fifth metatarsal heads (MH) were measured with FreeStep. Statistical analysis included 95% confidence interval, intragroup correlation coefficient (ICC1,1), one-way analysis of variance (one-way ANOVA), and least significant difference. The results showed that thickness and Young’s modulus of plantar fascia were the largest at the proximal fascia (PF) and decreased gradually from the proximal end to the distal end. Among the five distal branches (DB) of the fascia, the thickness and Young’s modulus of the second and third DB were larger. The peak pressures were also higher under the second and third MH. This study found a gradient distribution in that the thickness and Young’s modulus gradient decreased from the proximal end to the distal end of plantar fascia in the longitudinal arch of flexible flatfeet. In the transverse arch, the thickness and Young’s modulus under the second and third DB were larger than those under the other three DB in flexible flatfoot, and the peak pressures under the second and third MH were also larger than those under the other three MH in patients with flexible flatfoot. These findings deepen our understanding of the changes of biomechanical properties and may be meaningful for the study of pathological mechanisms and therapy for flexible flatfoot

    The Effect of Soft Tissue and Bone Morphology on the Stresses in the Foot and Ankle

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    The foot and ankle interface with the ground, thus they absorb reaction forces and initiate load distribution through the body. The plantar fascia (PF) is a flexible structure that absorbs reaction forces and distributes loading across the foot. It is frequently a source of foot pain especially when people have plantar fasciitis and/or diabetes mellitus. Finite element (FE) models of the foot and ankle were created to examine the function however, the plantar fascia is frequently modeled as a 1D tension only spring, which does not represent variations caused by injury and/or disease. As models move toward being patient specific, understanding what components of a model can be generic versus what should be patient specific is critical when minimizing the time to create and simulate results. The purpose of this dissertation was to develop 3D finite element foot and ankle models including different thickness of 3D solid plantar fascia (i.e., 3mm, 4mm, and 5mm) and different ankle positions (i.e., neutral position, 10° dorsiflexion, and 10° plantarflexion). Additionally, the effect of different thicknesses of cartilage (i.e., 0.5mm, 1.0mm, and 1.7mm) and bone morphology (health and injured) was investigated in a model of the talocrural joint. As the thickness of plantar fascia increased, the strains of plantar fascia were increased, and the peak plantar pressure moved from hindfoot to forefoot. Also, the peak plantar pressures were highest when the foot was in 10° of plantarflexion and lowest in the neutral position. Finally, contact area decreased with decreasing cartilage thickness, with a greater decrease in contact area in healthy ankles. In 3 models, contact stress increased as cartilage thickness decreased. The fourth model had little decrease in contact area, thus the contact pressures may have been affected more by bone morphology. In conclusion, in models of the foot and ankle, the plantar fascia can be generic if it is less than 4 mm thick, a variety of foot positions should be considered, and specific bone morphologies should be included in the ankle if there is a known pathology

    Myofascial release as a treatment choice for neuromuscular conditions : three randomized controlled trials and a systemic literature review

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    Introduction: Myofascial release (MFR) is a form of manual therapy that involves the application of a low load, long duration stretch to the myofascial complex, intended to restore optimal length, decrease pain, and improve function. MFR is being used to treat patients with a wide variety of conditions, but there is a scarcity of evidence to support its efficacy. Studies are emerging in this field with varying results and conclusions. Analysis of the recent research trials and reviews will be a better way to appraise the quality and reliability of such works. Objective: This work attempts to analyse and summarise the evidence from three randomised controlled trials (RCTs) and one systematic review of the effectiveness of MFR on various neuromuscular conditions and pain. Methodology: Effectiveness of MFR on tension type headache, lateral epicondylitis and chronic low back pain were the RCTs identified for the analysis. The systematic review selected analysed the published RCTs on MFR till 2014. The methodological qualities of the studies were assessed using the PEDro, Centre for Evidence-Based Medicine's (CEBM) Level of Evidence Scale, Risk of Bias (RoB) Analysis Tool and AMSTAR 2. Results: The RCTs analysed in this study were of moderate to high methodological quality (PEDro scale), with higher level of evidence (CEBM scale) and less bias (RoB). The effectiveness of MFR on tension type headache (TTH) was the first among the studies with a moderate methodological quality (6/10 in PEDro), with a 2b level of evidence on the CEBM scale. The study proved that direct technique or indirect technique MFR was more effective than the control intervention for TTH. The second RCT studied MFR for lateral epicondylitis (LE). The study was of a moderately high quality on the PEDro scale (7/10) with a 1b- level in CEBM. The MFR was found more effective than a control intervention for LE in computer professionals. The RCT on chronic low back pain (CLBP) also scored 7/10 in the PEDro scale and 1b in the CEBM scale. This study confirmed that MFR is a useful adjunct to specific back exercises and more helpful than a control intervention for CLBP. All three RCTs stated the usage of self-report measures and underpowered sample size as the major limitations along with a performance bias reported in the TTH trial. The systematic review demonstrated moderate methodological quality as per the AMSTAR 2 tool which analysed 19 RCTs for a result. The literature regarding the effectiveness of MFR was mixed in both quality and results. Omission of a risk of bias analysis was the major limitation of this review. The authors quoted that “MFR may be useful as either a unique therapy or as an adjunct therapy to other established therapies for a variety of conditions”. Conclusion: Critical appraisal is an important element of evidence-based medicine to carefully and systematically examine research to judge its trustworthiness, its value and relevance in a particular context. This review concludes that the three RCTs and the systematic review analysed were completed with moderate to good quality as per various quality measures, but with reported methodological flaws and interpretation biases. These studies with the critical appraisal can act as ‘pavements’ on which high quality future MFR trials and evidence can be built on

    The effect of foot orthoses on muscle activity and morphology, foot biomechanics and skin sensitivity

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    Foot orthoses with a medial wedge or medial arch support are commonly used to treat musculoskeletal pathologies by altering external forces applied to the foot, which could consequently alter internal forces generated by muscles. However, little is known about whether systematic changes in foot orthosis geometry result in systematic changes in activation of lower limb muscles. This PhD investigated the effects of foot orthoses on selected lower limb muscles. A systematic review was conducted to establish if evidence exists that footwear, foot orthoses and taping alter lower limb muscle activity during walking and running. The review identified some evidence that foot orthoses can decrease activity of tibialis posterior in early stance and possibly increase activity of peroneus longus in mid-late stance, while not altering activity of other lower limb muscles. Findings concerning the peroneus longus were limited by previous reports of the poor reliability of EMG recordings from this muscle. A reliability study was thereafter conducted to demonstrate a reliable protocol for recording EMG from the peroneus longus, using ultrasound guidance and small surface sensors to improve results. This technique was used in the subsequent study on the effect of foot orthoses on lower limb muscle activity. A study of the immediate effect of foot orthoses was undertaken, with the aim of establishing whether medial heel wedging and increased medial arch height affect EMG of shank muscles and foot and ankle moments/motion. Muscle activity was recorded from 23 healthy participants using surface EMG and fine-wire EMG (tibialis posterior) in combination with kinematic and kinetic data during walking in shoes with four different foot orthoses. Tibialis posterior activity decreased in early stance by 17% (p=0.001) with a Salfordinsole orthosis with an additional 8 mm increase in medial heel wedging and by 14% (p= 0.047) with a Salfordinsole orthosis with both a 6 mm increase in arch height and an 8 mm increase in heel medial wedging. The reduced tibialis posterior activity with medial wedging in combination with reduced external ankle eversion moment provides a possible link between foot orthosis design and biomechanical effect and could be used to inform treatment practice. Building on the literature review and the results of the immediate effects study, it was hypothesised that altered loading of the foot with long term use of foot orthoses would alter the mechanical work required of internal structures. The purpose of the final study in this PhD was to investigate any effect of using foot orthoses over three months on soft tissue morphology and skin sensitivity. Twenty three healthy participants wore an orthosis that changed peak pressure in the medial arch and the heel by 8%, while nineteen healthy participants continued to wear their convention footwear. There were no changes in skin sensitivity, or the thickness and cross sectional area of intrinsic foot muscles and connective tissue after three months of orthoses use. This finding provides evidence to challenge the view held by some that foot orthoses make muscles smaller (and weaker)

    Biomechanics of pressure ulcer in body tissues interacting with external forces during locomotion

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    2009-2010 > Academic research: refereed > Publication in refereed journalAuthor’s OriginalPublishe

    Consideration of monoarticular and biarticular mechanisms

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    Aktuelle In-vivo-Methoden zur Bewertung der Belastung und Dehnung der Achillessehne (AT) in der biomechanischen Literatur haben bestimmte EinschrĂ€nkungen, die sorgfĂ€ltig berĂŒcksichtigt werden mĂŒssen. Daher hatte die erste Studie zum Ziel, die AT-Dehnung und -Kraft wĂ€hrend der Fortbewegung mithilfe einer genauen, nicht-invasiven Methode zu messen. Die LĂ€nge der AT wurde unter BerĂŒcksichtigung ihrer KrĂŒmmung mit reflektierenden Folienmarkern von der Insertion am Fersenbein bis zum Übergang zwischen der Muskel-Sehnen-Verbindung des Musculus gastrocnemius medialis (GM-MTJ) gemessen. Die Kraft der AT wurde durch Anpassung einer quadratischen Funktion an die experimentelle Kraft-LĂ€ngen-Kurve der Sehne ermittelt, die aus maximalen freiwilligen isometrischen Kontraktionen (MVC) gewonnen wurde. Die Ergebnisse der zweiten Studie zeigen, dass eine Erhöhung der Gehgeschwindigkeit zu einer 21%igen Abnahme der maximalen AT-Kraft bei höheren Geschwindigkeiten im Vergleich zur bevorzugten Geschwindigkeit fĂŒhrt, wĂ€hrend die Nettobelastung der AT-Kraft am Sprunggelenk (ATF-Arbeit) in AbhĂ€ngigkeit von der Gehgeschwindigkeit zunimmt. DarĂŒber hinaus trugen eine frĂŒhere Plantarflexion, erhöhte elektromyografische AktivitĂ€t der Muskeln Sol und GM sowie der EnergieĂŒbertrag von Knie- zu Sprunggelenk durch die biartikulĂ€ren Musculi gastrocnemii zu einer 1,7- bzw. 2,4-fachen Zunahme der netto ATF-Mechanik-Arbeit bei Übergangs- und maximalen Gehgeschwindigkeiten bei. Das Ziel der dritten Studie war es, die in der ersten Studie vorgeschlagene Methode zu vereinfachen, indem die Anzahl der reflektierenden Folienmarker reduziert wurde, jedoch die hohe Genauigkeit beibehalten wurde. Die KrĂŒmmung der AT wurde mithilfe von reflektierenden Folienmarkern zwischen dem Ursprung des GM-MTJ und dem EinfĂŒhrungsmarker am Fersenbein beurteilt. Unsere Ergebnisse zeigen, dass eine Reduzierung der Anzahl der Folienmarker um 70% beim Gehen und um 50% beim Laufen zu einem marginalen Fehler fĂŒhren wĂŒrde und somit einen vernachlĂ€ssigbaren Effekt auf die LĂ€nge der AT und die maximale Dehnungsmessung hĂ€tte.Current in vivo methods to assess the Achilles tendon (AT) strain and loading in the biomechanics literature have certain limitations that require careful consideration. Therefore, the first study was to measure the AT strain and quantify AT force during locomotion with an accurate non-invasive method. AT length was measured considering its curvature using reflective foil markers from AT insertion at calcaneus to gastrocnemius medialis muscle-tendon junction (GM-MTJ). The force of the AT was calculated by fitting a quadratic function to the experimental tendon force-length curve obtained from maximum voluntary isometric contractions (MVC). The findings in second study indicate that an increase in walking speed leads to a 21% decrease in maximum AT force at higher speeds compared to the preferred speed, yet the net work of the AT force at the ankle joint (ATF-work) increased as a function of walking speed. Additionally, an earlier plantar flexion, increased electromyographic activity of the Sol and GM muscles, and knee-to-ankle joint energy transfer via the biarticular gastrocnemii contributed to a 1.7 and 2.4-fold increase in the net ATF-mechanical work in the transition and maximum walking speeds. The objective of the third study was to simplify the proposed method in the first study by reducing the number of foil reflective markers while preserving high accuracy. The AT curvature was assessed using reflective foil markers between the GM-MTJ origin and the calcaneal insertion marker. Our results indicate that reducing the number of foil markers by 70% during walking and 50% during running would result in a marginal error and, thus, a negligible effect on the AT length and maximum strain measurement

    Avaliação ecogråfica da morfologia muscular perante situaçÔes de sobrecarga agudas e crónicas

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    Introduction: Ultrasound (US) has an important role in musculoskeletal (MSK) evaluation, allowing the study of muscle morphology and function. Muscle thickness (MT) and muscle echo-intensity (EI) are two important parameters that may quantify muscle structural adaptations to a variety of stimuli. US elastography can also offer semi-quantitative and/or quantitative assessment of tissue stiffness providing relevant information about adaptations of muscle mechanical properties. Purpose: The general aim of the studies presented in this thesis is to explore the potential of quantitative US imaging for assessing the adaptations and responses of the muscle tissue to increased contractile activity using B-mode US and US elastography. The studies were centred on the quadriceps femoris muscle and addressed the study of the effect of strength training and of acute muscle contractile activity on MT, EI and muscle stiffness. Materials and methods: Three different studies were conducted and reported along this thesis. A total of 64 young adults of both genders participated in the studies. The first study (N = 20) evaluated the intra- and inter-session (one week apart) reproducibility of MT and EI parameters and the role of plane of view (transverse vs. longitudinal) and ROI dimension on measurements’ accuracy using the intraclass correlation coefficient [ICC(3,1)], the standard error of measurement (SEM), and the smallest detectable change (SDC). Bland-Altman analysis was used to study the level of agreement between plane views and ROI sizes. The second study (N = 28) investigated the effect of a 15-week strength program on MT and EI in several regions of the heads of the quadriceps femoris. This study included a control group and two training groups performing concentric or eccentric strength training. During this study, changes in vastus lateralis’ (VL) stiffness in response to strength training were evaluated using quasi-static elastography (QSE). In the final study (N = 16), acute changes in VL’s stiffness associated with passive stretching, performance of short but intense contractile activity, and muscle isometric contractions were investigated by means of supersonic shear wave imaging (SSI). Results: Moderate to very high reliability was found for MT (intra-session, ICCs: 0.82- 0.99; inter-session, ICCs: 0.70-0.98) and EI (intra-session, ICCs: 0.74-0.97; inter-session, ICCs: 0.48-0.94). In general, reliability for MT and EI measures was higher in the transverse plane and when using a larger ROI, respectively. Measurements of EI taken with a small versus a large ROI are associated with a small bias and larger limits of Morphological ultrasound evaluation in acute and chronic muscle overloading agreement (LoA). In study 2, 15 weeks of strength training increased MT in the majority but not in all of the scanned regions. Strength training failed in changing EI in most of the quadriceps femoris, excepting in the VI and some regions of the VL. Strength training significantly increased VL’s stiffness. No differences were observed in our quantitative US parameters between concentric and eccentric training. The final study demonstrated an acute increase of around 10% in VL’s shear modulus as a result of performing maximal isometric, concentric, and eccentric contractions. The shear modulus of the VL also increased when the knee moved from 10Âș to 50Âș and then to 90Âș flexion. Finally, a linear relationship between the shear modulus and the level of isometric muscle contraction was observed. Conclusions: Ultrasound measures of MT and EI show moderate to very high reliability. The reliability and agreement of MT and EI measurements are improved in transverse scans and with larger ROIs. QSE could demonstrate an increase in muscle stiffness as a result of strength training. SSI proved to be a good method to investigate muscle mechanical properties changes associated with muscle function. These results emphasise the value of an objective and quantifiable muscle US evaluation for studying muscle adaptation to exercise training and muscle function, in general.Introdução: A ultrassonografia tem um papel importante na avaliação mĂșsculoesquelĂ©tica, permitindo o estudo da morfologia e função muscular. A espessura muscular e a eco- intensidade muscular sĂŁo dois parĂąmetros importantes que podem quantificar as adaptaçÔes estruturais musculares, quando o musculo Ă© submetido a determinados estĂ­mulos. A elastografia por ultrassonografia pode, tambĂ©m, oferecer uma avaliação semi-quantitativa e/ou quantitativa da rigidez do tecido, fornecendo informaçÔes relevantes sobre as adaptaçÔes das propriedades mecĂąnicas musculares. Objetivo: O objetivo geral, dos estudos apresentados nesta tese, Ă© explorar o potencial da imagem quantitativa ultrassonogrĂĄfica, de forma a avaliar as adaptaçÔes e as respostas do tecido muscular ao aumento da atividade contrĂĄtil, usando a elastografia e a ultrassonografia em modo-B. Os estudos foram centrados no mĂșsculo do quadricĂ­pite femoral e abordaram o estudo do efeito do treino de força e da atividade contrĂĄtil muscular na espessura muscular, eco-intensidade e rigidez muscular. Materiais e mĂ©todos: TrĂȘs diferentes estudos foram realizados e descritos ao longo desta tese. Um total de 64 jovens adultos de ambos os gĂ©neros participaram dos estudos. No primeiro estudo (N = 20), foi analisada a reprodutibilidade da espessura muscular e da eco-intensidade dos quatro mĂșsculos que compĂ”em o quadricĂ­pite femoral. Para isso foram adquiridas trĂȘs imagens em modo B, nos planos longitudinal e transversal, em dois momentos distintos. A eco-intensidade foi medida usando dois tamanhos diferentes de regiĂŁo de interesse, um representado por uma forma retangular, medindo 70 mm2 e um outro representando o mĂĄximo do mĂșsculo apresentado na imagem ultrassonogrĂĄfica, evitando as fĂĄscias superficial e profundas do mesmo. A precisĂŁo das medidas foi, entĂŁo, analisada usando o Coeficiente de correlação intra-classe [ICC (3,1)], o erro padrĂŁo de medição (SEM) e a menor alteração detectĂĄvel (SDC). A anĂĄlise de Bland-Altman foi utilizada para estudar o nĂ­vel de concordĂąncia entre os planos de imagem ultrassonogrĂĄficos e os diferentes tamanhos da regiĂŁo de interesse. No segundo estudo (N = 28), analisou-se o efeito de um programa de treino de força, com duração de 15 semanas, sobre espessura muscular e ecointensidade em trĂȘs diferentes regiĂ”es de cada um dos quatro mĂșsculos que representam o quadricĂ­pite femoral: reto femoral, vasto intermĂ©dio, vasto medial e vasto lateral. Este estudo incluiu um grupo de controlo e dois grupos de treino, em que um realizou um protocolo de treino concĂȘntrico e o outro de treino excĂȘntrico. Durante este estudo, as alteraçÔes na rigidez do vasto lateral, em resposta ao treino de força foram avaliadas usando a elastografia quasi-statica, semi-quantitativa. No Ășltimo estudo (N = 16), foram analisadas as alteraçÔes agudas na rigidez de vasto lateral associadas ao alongamento passivo, ao desempenho de atividade contrĂĄtil de curta duração, mas intensa e Ă s contraçÔes isomĂ©tricas musculares usando a elastografia de onda supersĂłnica por cisalhamento. Resultados: Foi encontrada uma alta ou muito alta reprodutibilidade para espessura muscular (intra-sessĂŁo, ICCs: 0,82-0,99; inter-sessĂŁo, ICCs: 0,70-0,98) e eco-intensidade (intra-sessĂŁo, ICCs: 0,74-0,97; inter-sessĂŁo, ICCs: 0,48-0,94). Em geral, a reprodutibilidade para os valores da espessura muscular foi maior no plano transversal e no que diz respeito aos valores da eco-intensidade verificou-se uma melhor reprodutibilidade quando foi utilizada uma regiĂŁo de interesse de maiores dimensĂ”es. Um pequeno viĂ©s e menores valores de concordĂąncia caracterizam as medidas de cointensidade obtidas com uma regiĂŁo de interesse maior ou menor. No estudo 2, os participantes submetidos a 15 semanas de treino de força revelaram o aumento da sua espessura na maioria das regiĂ”es musculares avaliadas, mas nĂŁo em todas. NĂŁo foram encontradas alteraçÔes significavas dos valores da eco-intensidade com a realização do treino de força na maioria dos mĂșsculos do quadricĂ­pite femoral, excepto para o vasto intermĂ©dio e para algumas regiĂ”es do vasto lateral.Por outro lado, o treino de força aumentou significativamente a rigidez do vasto lateral. NĂŁo foram observadas diferenças significativas nos parĂąmetros quantitativos ultrassonogrĂĄficos entre o treino concĂȘntrico e excĂȘntrico. O Ășltimo estudo demonstrou um aumento agudo de cerca de10% nos valores da rigidez do vasto lateral como resultado da realização de contraçÔes mĂĄximas isomĂ©tricas, concĂȘntricas e excĂȘntricas. Os valores da rigidez do vasto lateral tambĂ©m aumentaram durante a flexĂŁo do joelho de 10Âș para 50Âș e posteriormente para 90Âș. Finalmente, observou-se uma relação linear entre os valores de rigidez do vasto lateral e o nĂ­vel de contração muscular isomĂ©trica do quadricĂ­pite femoral. ConclusĂ”es: As medidas ultrassonogrĂĄficas da espessura muscular e eco-intensidade mostram uma reprodutibilidade moderada a muito alta. A reprodutibilidade e a concordĂąncia das medidas de espessura muscular e eco-intensidade sĂŁo maiores no plano transversal e quando Ă© utilizada uma regiĂŁo de interesse de maior dimensĂŁo. A elastografia semi-quantitativa mostrou existir um aumento significativo na rigidez muscular como resultado do treino de força. A elastografia por onda de cisalhamento supersĂłnica Ă© um bom mĂ©todo para investigar as alteraçÔes das propriedades mecĂąnicas musculares associadas Ă  função muscular. Estes resultados enfatizam a importĂąncia de uma avaliação objetiva e quantificĂĄvel dos mĂșsculos por ultrassonografia, para estudar a adaptação muscular ao treino e função muscular, no geral

    The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies

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    The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice
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