TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Müller, Steffen A1 - Mayer, Frank T1 - Ultrasound evaluation of the patellar tendon cross-sectional area and its relation to maximum force T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 714 EP - 714 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - König, Niklas A1 - Mayer, Frank T1 - Reliability of variables defining mechanical and material properties of the achilles tendon T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 238 EP - 239 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - König, Niklas A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Inter-rater reliability and measurement error of sonographic muscle architecture assessments JF - Journal of ultrasound in medicine N2 - Objectives-Sonography of muscle architecture provides physicians and researchers with information about muscle function and muscle-related disorders. Inter-rater reliability is a crucial parameter in daily clinical routines. The aim of this study was to assess the inter-rater reliability of sonographic muscle architecture assessments and quantification of errors that arise from inconsistent probe positioning and image interpretation. Results-Inter-rater reliability was good overall (ICC, 0.77-0.90; IRV, 9.0%-13.4%; bias LoA, 0.2 +/- 0.2-1.7 +/- 3.0). Superior and inferior pennation angles showed high systematic bias and LoA in all setups, ranging from 2.0 degrees +/- 2.2 degrees to 3.4 degrees +/- 4.1 degrees. The highest IRV was found for muscle thickness (13.4%). "When the probe position was standardized, the SEM for muscle thickness decreased from 0.1 to 0.05 cm. Conclusions-Sonographic examination of muscle architecture of the medial gastrocnemius has good to high reliability. In contrast to pennation angle measurements, length measurements can be improved by standardization of the probe position. KW - gastrocnemius muscle KW - inter-rater variability KW - muscle architecture KW - musculoskeletal ultrasound KW - sonography Y1 - 2014 U6 - https://doi.org/10.7863/ultra.33.5.769 SN - 0278-4297 SN - 1550-9613 VL - 33 IS - 5 SP - 769 EP - 777 PB - American Institute of Ultrasound in Medicine CY - Laurel ER - TY - CHAP A1 - Hain, Gerrit A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Achilles tendon cross-sectional area changes during maximal voluntary isometric plantar-flexion contraction in healthy individuals. T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 47 EP - 47 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Hain, Gerrit A1 - Fröhlic, Katja A1 - Mayer, Frank T1 - Reliability of sonographic assessment of Achilles tendon cross-sectional area at rest and maximal voluntary contraction T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 47 EP - 47 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Risch, Lucie A1 - Cassel, Michael A1 - Messerschmidt, Janin A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Consistency and reliability of examining intratendinous blood flow in Achilles tendinopathy patients using doppler ultrasonography T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 46 EP - 46 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Reschke, Antje A1 - Cassel, Michael A1 - Intziegianni, Konstantina A1 - Mayer, Frank T1 - Intra- and inter-rater reliability of sonographic cross-sectional area measurements in asymptomatic patella tendons T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2014 SN - 0195-9131 SN - 1530-0315 VL - 46 IS - 5 SP - 927 EP - 928 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - König, Niklas A1 - Müller, Steffen A1 - Fröhlich, Katja A1 - Mayer, Frank T1 - Ultrasonography for the assessment of the structural properties of the Achilles tendon in asymptomatic individuals: An intra-rater reproducibility study JF - Isokinetics and exercise science : official journal of the European Isokinetic Society N2 - BACKGROUND: Reproducible measurements of tendon structural properties are a prerequisite for accurate diagnosis of tendon disorders and for determination of their mechanical properties. Despite the widely used application of Ultrasonography (US) in musculoskeletal assessment, its operator dependency and lack of standardization influences the consistency of the measurement. OBJECTIVE: To evaluate the intra-rater reproducibility of a standardized US method assessing the structural properties of the Achilles tendon (AT). METHODS: Sixteen asymptomatic participants were positioned prone on an isokinetic dynamometer with the knee extended and ankle at 90. flexion. US was used to assess AT-length, cross-sectional area (CSA), and AT-elongation during isometric plantarflexion contraction. The intra-rater reproducibility was assessed by ICC (2.1), Test-Retest Variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]), and Standard-Error of Measurement (SEM). RESULTS: Measurements of AT-length demonstrated an ICC of 0.93, TRV of 4.5 +/- 3.9%, Bias +/- LoA of -2.8 +/- 25.0 mm and SEM of 6.6 mm. AT-CSA showed an ICC of 0.79, TRV of 8.7 +/- 9.6%, Bias +/- LoA of 1.7 +/- 19.4 mm(2) and SEM of 5.3 mm(2). AT-elongation revealed an ICC of 0.92, TRV of 12.9 +/- 8.9%, Bias +/- LoA of 0.3 +/- 5.7 mm and SEM of 1.5 mm. CONCLUSIONS: The presented methodology allows a reproducible assessment of Achilles tendon structural properties when performed by a single rater. KW - Ultrasonography KW - Achilles tendon KW - reproducibility KW - isokinetic Y1 - 2015 U6 - https://doi.org/10.3233/IES-150586 SN - 0959-3020 SN - 1878-5913 VL - 23 IS - 4 SP - 263 EP - 270 PB - IOS Press CY - Amsterdam ER - TY - THES A1 - Intziegianni, Konstantina T1 - Influence of age and pathology on Achilles tendon properties under functional tasks T1 - Einfluss von Alter und Pathologie auf Eigenschaften der Achillessehne während funktionaler Aufgaben N2 - Prevalence of Achilles tendinopathy increases with age, leading to a weaker tendon with predisposition to rupture. Previous studies, investigating Achilles tendon (AT) properties, are restricted to standardized isometric conditions. Knowledge regarding the influence of age and pa-thology on AT response under functional tasks remains limited. Therefore, the aim of the thesis was to investigate the influence of age and pathology on AT properties during a single-leg vertical jump. Healthy children, asymptomatic adults and patients with Achilles tendinopathy participated. Ultrasonography was used to assess AT-length, AT-cross-sectional area and AT-elongation. The reliability of the methodology used was evaluated both Intra- and inter-rater at rest and at maximal isometric plantar-flexion contraction and was further implemented to investigate tendon properties during functional task. During the functional task a single-leg vertical jump on a force plate was performed while simultaneously AT elongation and vertical ground reaction forces were recorded. AT compliance [mm/N] (elongation/force) and AT strain [%] (elongation/length) were calculated. Differences between groups were evaluated with respect to age (children vs. adults) and pathology (asymptomatic adults vs. patients). Good to excellent reliability with low levels of variability was achieved in the assessment of AT properties. During the jumps AT elongation was found to be statistical significant higher in children. However, no statistical significant difference was found for force among the groups. AT compliance and strain were found to be statistical significant higher only in children. No significant differences were found between asymptomatic adults and patients with tendinopathy. The methodology used to assess AT properties is reliable, allowing its implementation into further investigations. Higher AT-compliance in children might be considered as a protective factor against load-related injuries. During functional task, when higher forces are acting on the AT, tendinopathy does not result in a weaker tendon. N2 - Die Prävalenz der Achillessehenentendinopathie steigt mit zunehmendem Alter, was zu einer geschwächten Sehnenstruktur mit Prädisposition zur Ruptur führt. Frühere Studien, welche Achillesssehnen(AS)-Eigenschaften untersuchten, beschränkten sich auf standardisierte isometrische Bedingungen. Der Einfluss von Alter und Pathologie auf das AS-Verhalten während funktioneller Bewegungen ist unklar. Das die Ziel der vorliegenden Arbeit war es daher, den Einfluss des Alters und Pathologie auf AS-Eigenschaften während einen einbeinigen vertikalen Sprung zu untersuchen. Es wurden gesunde Kinder, asymptomatische Erwachsene und Patienten mit Achillessehnene-ndinopathie eingeschlossen. Sonographisch wurden AS-Länge, -Querschnittsfläche (cross-sectional area) und -Dehnung gemessen. Intra- und inter-rater Reliabilität der genutzten Methoden wurden sowohl in Ruhe als auch unter maximaler isometrischer Plantarflexion bestimmt und nachfolgend zur Untersuchung der funktionellen AS-Eigenschaften implementiert. Hierzu wurde ein einbeiniger vertikaler Sprung auf einer Kraftmessplatte absolviert und zeitgleich AS-Compliance sowie vertikale Bodenreaktionskräfte regsitriert. AS-Compliance [mm/N] (Dehnung/Kraft) und AS-Verformung [%] (Dehnung/Länge) wurden kalkuliert. Die Gruppenunterschiede wurden in Bezug auf Alter (Kinder vs. Erwachsene) und Pathologie (Erwachsene vs. Patienten) evaluiert. Bei der Bewertung der verwendeten Methode wurde eine gute bis sehr gute Reliabilität mit geringer Variabilität zur Beurteilung der AS-Eigenschaften erreicht. Während der einbeinigen Sprünge zeigte sich eine statistisch signifikant höhere AS-Dehnung bei Kindern verglichen zu Erwachsenen. Ein statistisch signifikanter Kraft-Unterschied bestand zwischen den Gruppen nicht. AS-Compliance und –Verformung waren ausschließlich statistisch signifikant höher bei den Kindern. Keine signifikanten Unterschiede zwischen Erwachsenen und Patienten wurden gefunden. Die Methodik zur Bestimmung der AS-Eigenschaften ist zuverlässig, was deren Implementierung in weitere funktionelle Untersuchungen ermöglicht. Die höhere funktionelle AS-Compliance bei Kindern kann als Schutz vor Überlastungsschäden diskutiert werden. Während funktioneller Aufgaben, bei denen höhere Kräfte auf die AS wirken, ging das Vorhandensein einer Tendinopathie nicht mit einer schwächeren Sehne einher. KW - Achilles tendon KW - tendinopathy KW - age KW - reliability KW - tendon mechanical properties KW - Achillessehne KW - Tendinopathie KW - Alter KW - Sehnen mechanische Eigenschaften Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-398732 ER - TY - JOUR A1 - Intziegianni, Konstantina A1 - Cassel, Michael A1 - Rauf, S. A1 - White, S. A1 - Rector, Michael V. A1 - Kaplick, Hannes A1 - Wahmkow, Gunnar A1 - Kratzenstein, S. A1 - Mayer, Frank T1 - Influence of Age and Pathology on Achilles Tendon Properties During a Single-leg Jump JF - International journal of sports medicine N2 - Prevalence of Achilles tendinopathy increases with age leading to a weaker tendon with predisposition to rupture. Conclusive evidence of the influence of age and pathology on Achilles tendon (AT) properties remains limited, as previous studies are based on standardized isometric conditions. The study investigates the influence of age and pathology on AT properties during single-leg vertical jump (SLVJ). 10 children (C), 10 asymptomatic adults (A), and 10 tendinopathic patients (T) were included. AT elongation [mm] from rest to maximal displacement during a SLVJ on a force-plate was sonographically assessed. AT compliance [mm/N]) and strain [%] was calculated by dividing elongation by peak ground reaction force [N] and length, respectively. One-way ANOVA followed by Bonferroni post-hoc correction (=0.05) were used to compare C with A and A with T. AT elongation (p=0.004), compliance (p=0.001), and strain were found to be statistically significant higher in C (27 +/- 3mm, 0.026 +/- 0.006[mm/N], 13 +/- 2%) compared to A (21 +/- 4mm, 0.017 +/- 0.005[mm/N], 10 +/- 2%). No statistically significant differences (p0.05) was found between A and T (25 +/- 5mm, 0.019 +/- 0.004[mm/N], 12 +/- 3%). During SLVJ, tendon responded differently in regards to age and pathology with children having the most compliant AT. Higher compliance found in healthy tendons might be considered as a protective factor against load-related injuries. KW - children KW - tendinopathy KW - compliance KW - dynamic KW - ultrasonography Y1 - 2016 U6 - https://doi.org/10.1055/s-0042-108198 SN - 0172-4622 SN - 1439-3964 VL - 37 SP - 973 EP - 978 PB - Thieme CY - Stuttgart ER -