Purpose: Descriptive data on the aspects of site specific in vivo tendon strain with varying knee joint angle are non-existent. The present study determines and compares surface and deep layer strain of the patellar tendon during isometric contractions across a range of knee joint angles.
Methods: Male participants (age 22.0±3.4) performed ramped isometric knee extensions at knee joint angles of 90°, 70°, 50° and 30° of flexion. Strain patterns of the anterior and posterior regions of the patellar tendon were determined using real-time B-mode ultrasonography at each knee joint angle. Regional strain measures were compared using an automated pixel tracking method.
Results: Strain was seen to be greatest for both the anterior and posterior regions with the knee at 90° (7.76±0.89% and 5.06±0.76%). Anterior strain was seen to be significantly greater (p<0.05) than posterior strain for all knee angles apart from 30°, 90°=(7.76vs. 5.06%), 70°=(4.77vs. 3.75%), and 50°=(3.74vs. 2.90%). The relative strain (ratio of anterior to posterior), was greatest with the knee joint angle at 90°, and decreased as the knee joint angle reduced.
Conclusions: The results from this study indicate that not only are there greater absolute tendon strains with the knee in greater flexion, but that the knee joint angle affects the regional strain differentially, resulting in greater shear between the tendon layers with force application when the knee is in greater degrees of flexion. These results have important implications for rehabilitation and training.
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http://dx.doi.org/10.1016/j.jbiomech.2017.06.038 | DOI Listing |
Sci Rep
January 2025
Department of Radiology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Chuanshan Road No. 69, Hengyang, 421001, Hunan, China.
To determine the diagnostic performance of dual-energy CT (DECT) virtual noncalcium (VNCa) technique in the detection of bone marrow lesions (BMLs) in knee osteoarthritis, and further analyze the correlation between the severity of BMLs on VNCa image and the degree of knee pain. 23 consecutive patients with clinically diagnosed knee osteoarthritis were underwent DECT and 3.0T MRI between August 2017 and November 2018.
View Article and Find Full Text PDFOrthop Surg
January 2025
School of Exercise and Health Sciences, Xi'an Physical Education University, Xian, China.
Objective: Patellofemoral pain syndrome (PFPS) is a common knee issue, and hip joint function significantly affects knee health. Gluteus activation exercises are a promising treatment for PFPS. This study aims to investigate the impact of gluteal muscle activation exercises on the muscle involvement and movement patterns of young male patients with PFPS.
View Article and Find Full Text PDFJ Knee Surg
January 2025
Orthopedics, Seoul National University Bundang Hospital, Seongnam, Korea (the Republic of).
Categorization of alignment into phenotypes can be useful for predicting and analyzing postoperative alignment changes after opening-wedge high tibial osteotomy (OWHTO). The purposes of this study were (1) to develop a machine learning model for the predicting the Coronal Plane Alignment of the Knee (CPAK) phenotypes of final alignment after OWHTO, and (2) to analyze predictive factors for final alignment phenotypes. Data were retrospectively collected from 163 knees that underwent OWHTO between March 2014 and December 2019.
View Article and Find Full Text PDFJ Knee Surg
January 2025
Department of Orthopaedic Surgery, University of Louisville, Louisville, Kentucky.
Stiffness after total knee arthroplasty (TKA) can lead to decreased function and patient dissatisfaction. Manipulation under anesthesia (MUA) is often performed to improve range of motion (ROM); however, there is no consensus on indications or timing. The purpose of this study was to compare clinical results and patient-reported outcome measures (PROMs) between patients who underwent MUA versus those with an uncomplicated postoperative course following primary TKA.
View Article and Find Full Text PDFBrucellosis, caused by a facultative intracellular gram-negative coccobacillus, is one of the most common zoonotic infections worldwide. Very rarely, brucellosis can cause periprosthetic joint infections (PJI). In this case-based literature review, we summarize the current medical literature regarding Brucella PJI, with the aim to raise awareness among clinicians, particularly in non-endemic areas.
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