Orientador: Edson Rosa Pimentel / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T11:50:11Z (GMT). No. of bitstreams: 1 Guerra_FlaviaDaRe_D.pdf: 2578763 bytes, checksum: 4d00d5fa99bb0b97be32b1a4af7e825a (MD5) Previous issue date: 2013 / Resumo: O tendão calcanear é o tendão mais acometido por ruptura, particularmente em atividades esportivas. O processo de cicatrização resulta em uma matriz extracelular (MEC) menos organizada o que reduz sua resistência à tensão e torna-o mais susceptível à recorrência de lesões. A terapia com o laser de baixa potência (LBP) tem se mostrado efetiva, porém existem resultados contraditórios com relação a seus protocolos. Propusemos-nos a avaliar os efeitos de diferentes terapias com o LBP em tendão calcanear parcialmente seccionado. Para tal foram utilizados ratos Wistar machos adultos, distribuídos em 7 grupos experimentais: G1- Tendão intacto; G2-Tendão seccionado; G3- lesão + LBP (4J/cm2-contínuo); G4- lesão + LBP (4J/cm2-20 Hz); G5- Tendão seccionado; G6- lesão + LBP (4J/cm2-contínuo); G7- lesão + LBP (4J/cm2-20 Hz até o 7º dia e 2 KHz do 8º ao 14º dia). G2, G3 e G4 foram eutanaziados no 8º dia após lesão, e G5, G6 e G7 no 15º dia. Foram realizadas as dosagens de proteínas não-colagênicas (PNC), glicosaminoglicanos (GAG) e hidroxiprolina (HOPro), além de eletroforese em gel de agarose, zimografia para MMP-2 e -9 e western blotting (WB) para colágeno I e III. O estudo estrutural foi feito por meio de lâminas coradas em hematoxilina-eosina (HE) e azul de toluidina (AT) além de análise e medidas de birrefringência por meio de microscopia de polarização. A análise funcional foi realizada por meio do Catwalk. Com relação à HOPro houve um decréscimo significativo em todos os grupos quando comparados ao G1, exceto G7. A dosagem de GAG revelou um aumento em todos os grupos exceto G5 e o gel de agarose mostrou um aumento no conteúdo de dermatan sulfado em todos os grupos transeccionados, sendo menos expressivo em G4 e G7. Nos cortes corados com AT os grupos transeccionados apresentaram maior metacromasia, em especial os grupos tratados. WB para colágeno I mostrou um aumento em G4 e G7. Quanto ao colágeno III G4 apresentou valores maiores quando comparado a G2. A zimografia para MMP-2 indicou maiores valores em G4 e G7. A MMP-9 aumentou em G3 e G4. A análise de birrefringência revelou acentuada desorganização em todos os grupos, com melhora significativa em G7. Os resultados do catwalk apontaram que, após a cirurgia os grupos que receberam o laser pulsado conseguiram apoiar melhor a pata quando comparado aos demais grupos. Nossos resultados mostram que o LBP contínuo e pulsado tem efeitos diferentes sobre o processo de reparo do tendão. O LBP pulsado atuou sobre o processo inflamatório possibilitando que o animal apoiasse melhor a pata ao caminhar e promoveu a síntese e organização do colágeno. Desta maneira acreditamos que este protocolo de tratamento pode ser adaptado para o uso em clínicas de reabilitação de maneira a acelerar o reparo e melhorar as características morfológicas, bioquímicas e funcionais deste tendão / Abstract: The Achilles tendon has a high incidence of rupture, particularly in sports activities. The healing process leads to a disorganized extracellular matrix (ECM) which reduces its tensile strength and lead to a high rate of injury recurrence. Low level laser therapy (LLLT) has been effective, but there are conflicting results regarding their protocols. Our purpose was to evaluate the effects of different therapies with LLLT in partially tenotomized Achilles tendon. Adult male Wistar rats were divided into 7 groups: G1 ? intact; G2 ? injured; G3 ? injured + LLL (4 J/cm2 continuous); G4 ? injured + LLL (4 J/cm2 ? 20 Hz); G5 ? injured; G6 ? injured + LLL (4 J/cm2 continuous); and G7 ? injured + LLL (4 J/cm2 ? 20 Hz until the 7th day and 2 kHz from 8?14 days). G2, G3 and G4 were euthanized 8 days after injury, and G5, G6 and G7 were euthanized on the 15th day. Quantification of non-collagenous protein (NCP), glycosaminoglycans (GAG) and hydroxyproline (HOPro) was performed, in addition to electrophoresis on agarose gel, zymography for MMP-2 and -9, western blotting (WB) for collagen types I and III. The structural analysis was done by hematoxylin-eosin (HE) and toluidine blue (TB) staines with in addition to birefringence measurements and analysis by polarization microscopy. Functional analysis was performed using the gait assessment of the animals in the Catwalk. Regarding HOPro there was a significant decrease in all groups when compared to the G1, except G7. The dosage of GAG showed an increase in all groups except G5 and agarose gel showed an increase in the content of dermatan sulfat in all transected groups, being less expressive in G4 and G7. In sections stained with TB the tenotomized groups showed metachromasia, particularly the treated groups. WB for collagen I showed an increase in G4 and G7. In G4 collagen III showed higher values when compared to G2. The zymography for MMPs-2 showed higher values for G4 and G7. MMP-9 increased in G3 and G4. Analysis of birefringence showed marked disorganization in all groups, with a significant improvement in G7. The catwalk results showed that after surgery, G4 had better results when compared to other groups. Our results show that the continuous and pulsed LLLT has different effects on the process of tendon repair. Pulsed laser acted on the inflammatory process improving the gait and promoting collagen synthesis and organization. Thus we believe that this treatment protocol can be adapted for use in rehabilitation clinics in order to accelerate the repair and enhance the morphological, biochemical and functional characteristics of the tendon / Doutorado / Anatomia / Doutora em Biologia Celular e Estrutural

Abstract The purposes of the present research were to compare the outcome after Achilles tendon rupture repair in two postoperative regimens, to compare Achilles tendon elongation in two postoperative treatment methods, to compare the effects of two postoperative methods on motor performance aspects such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination, to test the mechanical properties of the recently developed poly-L/D-lactide (PLDLA) sutures and Maxon® sutures when implanted in the Achilles tendons of rabbits, and to study the histological tissue reactions and biodegradation of these sutures under the same conditions. Isokinetic calf muscle strength scores at the last control check-up were excellent in 56% of the patients in the early motion group, good in 32%, fair in 8%, and poor in 4%, whereas the scores in the cast group were excellent in 29% of cases, good in 50% and fair in 21%. The ankle performance scores were excellent or good in 88% of the patients in the early motion group, fair in 4% and poor in 8%, whereas the scores in the cast group were excellent or good in 92% of cases and fair in 8%. No significant differences were seen between the two groups at 3 months and at the last control checkups with regard to pain, stiffness, subjective calf muscle weakness, footwear restrictions, range of ankle motion, isokinetic calf muscle strength or overall outcome. The complications included 1 re-rupture in the early motion group and 1 deep infection and 2 re-ruptures in the cast group. AT elongation occurred in both groups, but was somewhat less marked in the early motion group. The AT elongation curves rose at first and then fell slowly in both groups. The patients who had less AT elongation achieved a better clinical outcome. AT elongation did not correlate significantly with age, body mass index or isokinetic peak torques. The recovery of motor performance functions such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination did not depend on the two postoperative regimens. The motor functions of the operated leg had obviously recovered to the level of the non-operated leg 12 weeks after the operation. Sutures made of PLDLA were used successfully for Achilles tendon repair in rabbits. There was no significant difference between the in vitro and in vivo tensile strength retention of the sutures. By comparison with Maxon®, PLDLA was found to have a lower initial tensile strength but more prolonged strength retention. The breaking strength values of the Achilles tendons repaired with sutures of these types were not significantly different at 6 weeks. Intratendinous PLDLA sutures formed a thinner fibrous capsule during the 12-week follow-up period than did Maxon® sutures of the same diameter. The suture materials had not been totally absorbed by 12 weeks.

Abstract The Achilles tendon is the strongest and largest of human tendons, and its proper function is essential for normal gait. Most acute Achilles tendon injuries occur during sports, particularly in ball games. The purposes of this study were (1) to examine the incidence of total Achilles tendon rupture (ATR) over a 33-year period in the city of Oulu and to investigate its changes with respect to age, sex, and injury mechanism. (2) to compare ≥10-year outcomes of two postoperative regimens after ATR repair: early weightbearing with early mobilization versus early weightbearing with early immobilization in tension, (3) to compare clinical outcome and calf muscle strength recovery after conservative treatment or open surgical repair of acute ATR, followed by identical accelerated rehabilitation programs. The overall incidence per 100 000 person years increased from 2.1 in 1979 to 21.5 in 2011. The incidence increased in all age groups. The incidence of sports-related ruptures increased during the second 11-year period, whereas the incidence of non-sports-related ruptures increased steadily over the entire study period. Early mobilization and immobilization in tension after ATR repair resulted in similar clinical outcomes and isokinetic strengths. Regardless of patient satisfaction with the operative treatment, calf muscle strength did not recover normally, even at the 10-year follow-up. Surgery and conservative treatment of acute ATR resulted in similar Achilles tendon performance score after 18 months, but surgery restored calf muscle strength earlier. Surgery also resulted in better health-related quality of life in the domains of physical functioning and bodily pain. Conservative treatment with a functional protocol is recommended for a large majority of patients. However, patients with high physical expectations could still benefit from operative treatment. In conclusion, the incidence of ATR is rising, postoperative immobilization and early mobilization result in similar long-term results in terms of the Achilles tendon performance score and calf muscle function, and conservative treatment with a functional protocol is the preferred treatment for the majority of patients. / Tiivistelmä Akillesjänne on ihmisen suurin ja vahvin jänne ja sen kunnollinen toiminta on edellytys normaalille kävelylle. Suurin osa akillesjänteen repeämistä syntyy urheilussa, erityisesti pallopeleissä. Ensimmäisessä osatyössä oli tarkoitus selvittää täydellisten akillesjänteen repeämien esiintyvyys Oulussa 33 vuoden aikana ja selvittää potilaiden ikä ja sukupuoli sekä vammamekanismi. Toisessa osatyössä vertailtiin akillesjänteen repeämän hoitotuloksia 11 vuotta vamman jälkeen. Tässä tutkimuksessa verrattiin kahta erilaista leikkauksen jälkeistä hoitomenetelmää; toisessa sallittiin varhainen varaaminen ja nilkan liikuttelu kun taas toisessa sallittiin varhainen varaaminen, mutta nilkka kipsattiin ojennukseen. Kolmannessa osatyössä vertailtiin tuloksia leikattujen ja ilman leikkausta hoidettujen potilaiden välillä. Molemmat ryhmät hoidettiin samanlaisella irrotettavalla varaamisen sallivalla lastalla. Akillesjänteen repeämien esiintyvyys oli 2.1/100 000 vuonna 1979 ja nousi vuoteen 2011 mennessä 21.5/100 000:een ja nousua oli kaikissa ikäryhmissä. Urheiluun liittyvät repeämät lisääntyivät erityisesti jakson keskimmäisen 11-vuotis jakson aikana kun taas urheiluun liittymättömät repeämät lisääntyivät koko seurantajakson ajan. Vertailtaessa kahta erilaista leikkauksen jälkeistä hoitomenetelmää todettiin ettei potilaiden välillä ollut eroa kliinisissä mittareissa tai voimissa 11 vuotta vamman jälkeen. Vaikka potilastyytyväisyys oli hyvä ei pohkeen voima palautunut normaaliksi edes 11 vuotta vamman jälkeen. Vertailtaessa leikkauksella ja ilman leikkausta hoidettuja potilaita ei myöskään todettu eroja kliinisissä mittareissa, mutta kirurgisella hoidolla voima palautui hiukan nopeammin ja ero myös säilyi 18 kuukautta vammasta. Myös elämänlaatumittarilla mitattuna leikkauksella hoidetut olivat kivun ja fyysisen toiminnan osalta tyytyväisempiä. Suurimmalle osalle potilaista konservatiivinen hoito sopii erinomaisesti, mutta jotkut fyysisesti aktiiviset potilaat hyötynevät leikkaushoidosta.

O objetivo deste estudo foi avaliar o efeito dos tempos de aplicação 3, 4 e 5 minutos por ERA do ultrassom terapêutico (UST) na organização das fibras de colágeno em lesão do tendão do calcâneo de ratos. Foram utilizados quarenta ratos machos Wistar, dos quais 32 sofreram tenotomia total do tendão do calcâneo e foram divididos em 5 grupos: GC, sem tenotomia e tratamento; GT, com tenotomia e sem tratamento; UST3, UST4 e UST5 submetidos à tenotomia e tratados com UST nos tempos de 3, 4 e 5 minutos por área de radiação efetiva respectivamente. Os animais foram submetidos à primeira aplicação do UST foi 24 horas após a cirurgia de tenotomia. A irradiação ultrassônica foi aplicada com os seguintes parâmetros: 1 MHz, modo pulsado com 20% do ciclo de trabalho (2 ms de emissão / 8 ms de intervalo), frequência de 100 Hz, 0,5 W / cm² de intensidade e ERA de 0,5 cm². A aplicação foi realizada 1x/dia. Os animais foram sacrificados após a 10ª sessão de tratamento, no 12º dia pós-operatório. Os tendões foram retirados cirurgicamente para análise da organização das fibras colágenas através do método de birrefringência (retardo óptico - OR). As fibras colágenas mostraram melhor agregação e organização no grupo UST3, UST4 e UST5 quando comparado ao GT (p<0.05) e o UST5 apresentou melhor resposta na comparação intergrupos. Conclui-se que o UST, aplicado no tempo de 5 minutos por área de radiação efetiva, apresentou a melhor dose-resposta quanto à organização das fibras colágenas no reparo tecidual de tendões de ratos / The aim of this study was to evaluate the effect of application times 3, 4 and 5 minutes ERA of therapeutic ultrasound in the organization of the collagen fibers in rat calcaneal tendon injury. Forty male Wistar rats were used, of which 32 underwent complete tenotomy of the calcaneal tendon and were divided into 5 groups: GC without tenotomy and treatment; GT tenotomy with and without treatment; UST3, UST4 UST5 and submitted to tenotomy treated with therapeutic ultrasound at times 3, 4 and 5 minutes per effective radiating area respectively. The animals were submitted to the first application of therapy US tenotomy 24 hours after surgery. Ultrasonic irradiation was applied with the following parameters: 1 MHz, pulsed mode at 20% duty cycle (2ms transmission / 8 ms interval), frequency 100 Hz, 0.5 W / cm² intensity and ERA 0.5 cm². The application was performed 1x / day. The animals were sacrificed after the 10th treatment session, on the 12th postoperative day. The tendons were surgically removed for analysis of the organization of the collagen fibers through birefringence method (optical delay - OR). The collagen fibers showed better aggregation and organization in group UST3, UST4 and UST5 when compared to the GT (p <0.05) and UST5 showed better response in the intergroup comparison. We conclude that the UST, applied in time of 5 minutes for effective radiation area, presented the best dose-response as the organization of the collagen fibers in tissue repair of rat tendons

Syftet med denna systematiska litteraturöversikt var att jämföra radiell mot fokuserad stötvågsbehandling samt att undersöka effekten utav stötvågsbehandling för att reducera smärta och återfå fysisk funktion vid Akillestendinopati. Litteraturöversikten har följt checklistan PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis). Inklusionskriterier till litteraturöversikten är utformade efter PICO (population, intervention, control, outcome) och databaser som använts är PubMed, SPORTDiscus, CINAHL, Scopus och Web of Science. Data har analyserats narrativt och tillförlitligheten hos utfallen har bedömts med GRADE.Sju studier inkluderades till litteraturöversikten varav fyra studier som utfört radiell och tre studier som utfört fokuserad stötvågsbehandling som intervention. En signifikant skillnad för smärtreduktion sågs i två av studierna för båda behandlingarna. När radiell stötvågsbehandling användes hade interventionsgrupperna en högre smärtreduktion än kontrollgrupperna och när fokuserad stötvågsbehandling användes hade kontrollgrupperna en högre smärtreduktion än interventionsgrupperna. En signifikant skillnad för återställande utav den fysiska funktionen i ankeln sågs i tre studier för radiell stötvågsbehandling och två studier för fokuserad stötvågsbehandling. Där radiell stötvågsbehandling användes hade interventionsgrupperna en större ökad fysisk funktion än kontrollgrupperna och där fokuserad stötvågsbehandling användes hade kontrollgrupperna en större ökad fysisk funktion än interventionsgrupperna.Radiell stötvågsbehandling verkar kunna fungera för att reducera smärta och öka fysisk funktion vid Akillestendinopati. Tillförlitligheten för utfallen vid fokuserad stötvågsbehandling är för låg för att kunna dra någon slutsats om vilken typ av stötvågsbehandling som är mest effektiv. Ifall det varit känt vilken typ av stötvågsbehandling som ger bäst resultat hade det varit en bra vägledning för vårdpersonal som arbetar med stötvågsbehandling. / The purpose of this review was to compare radial versus focused shock wave therapy and to review shock wave therapies usage to reduce pain and increase physical function for the Achilles tendinopathy.The review has followed PRISMA’s checklist while using PubMed, SPORTDiscus, CINAHL, Scopus and Web of Science databases. Data has been analyzed narratively and the evidence of the outcomes has been assessed.A significant difference in pain reduction was seen within two studies for both interventions. Where radial shock wave therapy was administered the intervention groups had a higher pain reduction than the control group. Where focused shock wave therapy was administered the control group had a higher pain reduction than the intervention group. A significant difference in the restoration of physical function was seen within three studies for radial shock wave therapy and two studies for focused shock wave therapy. Where radial shock wave therapy was administered the intervention groups had a greater increased physical function than the control groups and where focused shock wave treatment was administered the control groups had a greater increased physical function than the intervention groups.Radial shock wave therapy seems to be effective to reduce pain and increase physical function in the Achilles tendinopathy. The evidence of the results for focused shock wave therapy is too low to draw any conclusion, or allow us to compare the two methods. Had the studies allowed for a direct comparison between the two methods, this could have led to a guide for healthcare professionals.

No description available.

Diplomová práce Účinky rázové vlny v léčbě tendinopatie Achillovy šlachy 1 Abstract This thesis focuses on the observation of the effects of low-energetic focused extracorporeal shock wave therapy (ESWT) in the treatment of Achilles tendinopathy. The theoretical part summarizes the current knowledge of anatomical, histological, kinesiological and biomechanical aspects of Achilles tendon (AT), as well as pathological processes, which can be described as Achilles tendinopathy, their differential diagnosis and treatment options. Last but not least, we present up-to-date information on the physical principles and biological effects of ESWT, not only in the treatment of AT diseases. The main goal of our research was to determine the effectiveness of low-energetic focused ESWT in the treatment of Achilles tendinopathy in comparison to the placebo group. The subject of observation was not only changes in clinical manifestations, but also possible changes in the morphology of AT using ultrasonography (USG). Methods: A total of 20 patients with symptomatic Achilles tendinopathy was included in the study, while only 18 of them completed the entire program, and therefore only the results of these patients were evaluated. They were randomly divided into two groups in 1:1 ratio. Group A was treated by ESWT with...

In this study, we examined how hill running affects the Achilles tendon, which is a common location for injuries in runners. Twenty females ran for 10 min on three randomly selected grades (-6%, 0%, +6%). Achilles tendon (AT) cross-sectional area (CSA) was imaged using Doppler ultrasound and peak vertical forces were analyzed using high-speed (240 Hz) videography. A metabolic cart and gas analyzer ensured a similar metabolic cost across grades. Data were analyzed using a forward selection regression. Results showed a decrease in AT CSA from pre-run to post-run (p = .0001). Peak vertical forces were different across grades (p = .0001) with the largest occurring during downhill running and smallest during uphill running. The results suggest that the Achilles tendon is affected by running and a decrease in CSA appears to be a normal response. The AT CSA does not differ between grade conditions when metabolic cost of running is matched, suggesting an adaptive effect of the AT. Coaches and athletes can use this knowledge to develop workout protocols that transition runners to downhill running and allow them to adapt to these greater forces.

Genom att generera mer information om hälsenan i form av dess elasticitet kan förhoppningsvis fler slutsater nås gällande diagnostik och behandling. Elastografi med hjälp av ultraljud skulle kunna vara en metod för att bidra med denna information. För att utföra detta anpassades en mjukvara utifrån ett grundläggande basprogram för elastografimätningar, utvecklat av företaget Verasonics, för att kunna utföra elastografi av hälsenan genom programmering i matlab. Tidigare undersökningsmetoder för elastografi är utvecklade för större organ, varför anpassningen innebar att använda metoder som även ger tillförlitlig information för mindre organ. För att göra detta anpassades först mjukvaran för en mindre fantom med liknande djup som hälsenan. När det konstaterats att skjuvningsvågor genererats på rätt avstånd kunde sedan mätningar göras på hälsenan. Genom att bestämma hastigheten av de genererade skjuvningsvågorna kunde sedan skjuvmodulen, följt av elasticitetsmodulen, beräknas för vävnaden. Denna bestämdes först genom grupphastigheten av skjuvningsvågorna, vilket är den metod som används vid större organ, följt av fashastigheten av skjuvningsvågorna vilket tar hänsyn till vågens dispersion. Detta gav då hälsenans elasticitetsmodul enligt grupphastighet samt fashastighet som sedan kunde jämföras. Slutligen gick det att konstatera att elasticitetsmodulen kommer att variera beroende på vilken typ av hastighet denna härleds från. Detta indikerar då på att sjuvningsvågen interagerar med organets gränsyta vilket orsakar dispersion. / Generating more information about the achilles tendon, such as its elasticity, will hopefully lead to more conclusions and results within both diagnostics as well as treatment. Elastography by ultrasound could be a method to contribute with this information. To do so, a basic software,provided and developed by the company Verasonics for elastography was specialized to fit the achilles tendon by programing in matlab. Earlier methods to perform elastography are developed for larger organs, hence the adjustment will include methods that acquire trustworthy information from smaller organs. To do so the adjustment of the software was first made to work on a smaller phantom with similar symmetry as the achilles tendon. When it was confirmed that shear waves were generated at the correct distance this enabled further measurements on the achilles tendon. By deciding the speed of the generated shear waves the shear modulus, followed by the elastic modulus, could then be estimated for the tissue. This was first decided by the group velocity of the shear waves, as the usual method done on larger organs, followed by the phase velocity that also takes dispersion in mind. The result could then be used to obtain the elastic modulus of the achilles tendon based on group and phase velocity for further comparison.The conclusion was then that the elastic modulus will depend on what kind of velocity it is derived from. This indicates that the shear wave interacts with the organ's boundaries which causes dispersion.

Aktuelle In-vivo-Methoden zur Bewertung der Belastung und Dehnung der Achillessehne (AT) in der biomechanischen Literatur haben bestimmte Einschränkungen, die sorgfältig berücksichtigt werden müssen. Daher hatte die erste Studie zum Ziel, die AT-Dehnung und -Kraft während der Fortbewegung mithilfe einer genauen, nicht-invasiven Methode zu messen. Die Länge der AT wurde unter Berücksichtigung ihrer Krümmung 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-Längen-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 führt, während die Nettobelastung der AT-Kraft am Sprunggelenk (ATF-Arbeit) in Abhängigkeit von der Gehgeschwindigkeit zunimmt. Darüber hinaus trugen eine frühere Plantarflexion, erhöhte elektromyografische Aktivität der Muskeln Sol und GM sowie der Energieübertrag von Knie- zu Sprunggelenk durch die biartikulären 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 Krümmung der AT wurde mithilfe von reflektierenden Folienmarkern zwischen dem Ursprung des GM-MTJ und dem Einführungsmarker 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 führen würde und somit einen vernachlässigbaren Effekt auf die Länge der AT und die maximale Dehnungsmessung hätte. / 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.