The purpose of this study was to estimate and compare the moment arm length of the patellar tendon (d) during passive knee extension using three different reference landmarks; instant centre of rotation (ICR), tibiofemoral contact point (TFCP) and geometrical centre of the posterior femoral condyles (GCFC). Measurements were taken on the right leg on seven healthy males during passive knee rotation performed by the motor of a Cybex Norm isokinetic dynamometer. Moment arms lengths were obtained by analysing lateral X-ray images recorded using a GE FlexiView 8800 C-arm videofluoroscopy system. The d-knee joint angle relations with respect to GCFC and ICR were similar, with decreasing values from full knee extension (~5.8 cm for d (GCFC) and ~5.9 cm for d (ICR)) to 90 degrees of knee flexion (~4.8 cm for both d (GCFC) and d (ICR)). However, the d (TFCP)-knee joint angle relation had an ascending-descending shape, with the highest d (TFCP) value (~5 cm) at 60 degrees of knee flexion. There was no significant difference between the GCFC and ICR methods at any knee joint angle. In contrast, there were significant differences (P < 0.01) between d (ICR) and d (TFCP) at 0 degrees , 15 degrees , 30 degrees and 45 degrees of knee flexion and between d (GCFC) and d (TFCP) at 0 degrees , 15 degrees and 30 degrees of knee flexion (P < 0.01). This study shows that when using different knee joint rotation centre definitions, there are significant differences in the estimates of the patellar tendon moment arm length, especially in more extended knee joint positions. These differences can have serious implications for joint modelling and loading applications.
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http://dx.doi.org/10.1007/s00421-008-0968-3 | DOI Listing |
Diabetes Obes Metab
January 2025
School of Exercise and Health, Shanghai Frontiers Science Research Base of Exercise and Metabolic Health, Shanghai University of Sport, Shanghai, China.
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Anal Chem
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Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
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View Article and Find Full Text PDFSoft Matter
January 2025
Physical Chemistry, Chemistry Centre, Lund University, SE-22100 Lund, Sweden.
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View Article and Find Full Text PDFAm J Cancer Res
December 2024
Department of General Surgery, Liaoning University of Traditional Chinese Medicine Affiliated Hospital Shenyang 110032, Liaoning, China.
The involvement of axillary lymph nodes (ALNs) is a critical prognostic factor affecting patient management and outcomes in breast cancer (BC). This study aims to comprehensively analyze the clinical data of BC patients, evaluate ultrasonic signs of ALNs, and explore the implications of a prediction model for ALN metastasis (ALNM) in early-stage BC patients based on ultrasonic features and clinical data. This study retrospectively analyzed ultrasonic features and clinical data from 216 patients diagnosed with unilateral invasive BC.
View Article and Find Full Text PDFWe present a comprehensive genetic investigation of Late Neolithic (LN) and Early Copper Age (ECA) populations living in the Carpathian Basin, leveraging whole genome data from 125 previously unreported individuals. Using population genetics, kinship analyses and the study of networks of identity-by-descent haplotype segment sharing, we elucidate the social and genetic dynamics of these communities between 4800-3900 cal BCE. Despite changes in settlement patterns, burial practices, and material culture, we document a high degree of genetic continuity.
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