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المؤلفون: Emily L. Bishop, Chris Cowper-Smith, Chris A. McGibbon, Edmund Biden, Scott C.E. Brandon

المصدر: Frontiers in Bioengineering and Biotechnology, Vol 8 (2021)
Frontiers in Bioengineering and Biotechnology

مصطلحات موضوعية: musculoskeletal diseases, tibiofemoral force, Histology, lcsh:Biotechnology, Biomedical Engineering, tendon force, Bioengineering, Osteoarthritis, Knee Joint, medicine.disease_cause, Contact force, Weight-bearing, 03 medical and health sciences, 0302 clinical medicine, lcsh:TP248.13-248.65, medicine, Original Research, 030203 arthritis & rheumatology, Orthodontics, business.industry, Work (physics), Bioengineering and Biotechnology, knee brace, 030229 sport sciences, medicine.disease, musculoskeletal system, simulation, Sagittal plane, Brace, osteoarthritis, medicine.anatomical_structure, cruciate force, Quadriceps tendon, patellofemoral force, business, human activities, deep knee bend, Biotechnology

الوصف: Objective: Off-loader knee braces have traditionally focused on redistributing loads away from either the medial or lateral tibiofemoral (TF) compartments. In this article, we study the potential of a novel “tricompartment unloader” (TCU) knee brace intended to simultaneously unload both the patellofemoral (PF) and TF joints during knee flexion. Three different models of the TCU brace are evaluated for their potential to unload the knee joint.Methods: A sagittal plane model of the knee was used to compute PF and TF contact forces, patellar and quadriceps tendon forces, and forces in the anterior and posterior cruciate ligaments during a deep knee bend (DKB) test using motion analysis data from eight participants. Forces were computed for the observed (no brace) and simulated braced conditions. A sensitivity and validity analysis was conducted to determine the valid output range for the model, and Statistical Parameter Mapping was used to quantify the effectual region of the different TCU brace models.Results: PF and TF joint force calculations were valid between ~0 and 100 degrees of flexion. All three simulated brace models significantly (p < 0.001) reduced predicted knee joint loads (by 30–50%) across all structures, at knee flexion angles >~30 degrees during DKB.Conclusions: The TCU brace is predicted to reduce PF and TF knee joint contact loads during weight-bearing activity requiring knee flexion angles between 30 and 100 degrees; this effect may be clinically beneficial for pain reduction or rehabilitation from common knee injuries or joint disorders. Future work is needed to assess the range of possible clinical and prophylactic benefits of the TCU brace.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::128442d53f38629910f93d0f6e23b445

المؤلفون: Sebastian Klich, Krzysztof Ficek, Igor Krymski, Andrzej Klimek, Adam Kawczyński, Pascal Madeleine, Cesar Fernández-de-las-Peñas

المصدر: Frontiers in Physiology
Frontiers in Physiology, Vol 11 (2020)
Klich, S, Ficek, K, Krymski, I, Klimek, A, Kawczyński, A, Madeleine, P & Fernández-de-Las-Peñas, C 2020, ' Quadriceps and Patellar Tendon Thickness and Stiffness in Elite Track Cyclists : An Ultrasonographic and Myotonometric Evaluation ', Frontiers in Physiology, vol. 11, 607208 . https://doi.org/10.3389/fphys.2020.607208

مصطلحات موضوعية: musculoskeletal diseases, medicine.medical_specialty, tendon, Physiology, Vastus medialis, lcsh:Physiology, stiffness, 03 medical and health sciences, 0302 clinical medicine, Physical medicine and rehabilitation, track cycling, Physiology (medical), medicine, Original Research, lcsh:QP1-981, business.industry, maps, Track (disk drive), Stiffness, 030229 sport sciences, musculoskeletal system, thickness, Patellar tendon, Tendon, medicine.anatomical_structure, Sprint, Patella, Quadriceps tendon, medicine.symptom, business, human activities, 030217 neurology & neurosurgery

الوصف: Track cyclists are required to perform short- and long-term efforts during sprint and endurance race events, respectively. The 200 m flying sprint races require maximal power output and anaerobic capacity, while the 4,000 m pursuit cyclists demand a high level of aerobic capacity. Our goal was to investigate spatial changes in morphological and mechanical properties displayed using 3D topographical maps of the quadriceps muscle and tendons after 200 m flying start and 4,000 m individual pursuit race in elite track cyclists. We hypothesized a non-uniform distribution of the changes in the quadriceps muscle stiffness (QMstiff), and acute alterations in quadriceps tendon (QTthick) and patellar tendon (PTthick) thickness. Fifteen men elite sprint and 15 elite men endurance track cyclists participated. Sprint track cyclists participated in a 200 m flying start, while endurance track cyclists in 4,000 m individual pursuit. Outcomes including QTthick (5–10–15 mm proximal to the upper edge of the patella), PTthick (5–10–15–20 mm inferior to the apex of the patella)—using ultrasonography evaluation, QMstiff, and quadriceps tendon stiffness (QTstiff) were measured according to anatomically defined locations (point 1–8) and patellar tendon stiffness (PTstiff)—using myotonometry, measured in a midway point between the patella distal and the tuberosity of tibial. All parameters were assessed before and after (up to 5 min) the 200 m or 4,000 m events. Sprint track cyclists had significantly larger QTthick and PTthick than endurance track cyclists. Post-hoc analysis showed significant spatial differences in QMstiff between rectus femoris, vastus lateralis, and vastus medialis in sprint track cyclists. At before race, sprint track cyclists presented significantly higher mean QTthick and PTthick, and higher QMstiff and the QTstiff, as compared with the endurance track cyclists. The observed changes in PTThick and QTThick were mostly related to adaptation-based vascularity and hypertrophy processes. The current study suggests that assessments using both ultrasonography and myotonometry provides crucial information about tendons and muscles properties and their acute adaptation to exercise. Higher stiffness in sprint compared with endurance track cyclists at baseline seems to highlight alterations in mechanical properties of the tendon and muscle that could lead to overuse injuries.

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URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::04937f3acbba33b526d53d2cb8364097
https://doi.org/10.3389/fphys.2020.607208

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المؤلفون: Jacob Edward Earp, Robert U Newton, Prue Cormie, Anthony John Blazevich

المصدر: Frontiers in Physiology
Frontiers in Physiology, Vol 7 (2016)

مصطلحات موضوعية: musculoskeletal diseases, quadriceps, Materials science, tendon, Physiology, Young's modulus, Squat, Concentric, lcsh:Physiology, 03 medical and health sciences, 0302 clinical medicine, viscoelastic, Physiology (medical), One-repetition maximum, medicine, Eccentric, Force platform, Original Research, fascicle, lcsh:QP1-981, Patellar ligament, 030229 sport sciences, Anatomy, musculoskeletal system, Tendon, medicine.anatomical_structure, patellar, Quadriceps tendon, rate of force development, 030217 neurology & neurosurgery, Biomedical engineering

الوصف: Introduction: Tendon dynamics influence movement performance and provides the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Methods: Ten resistance-trained men [squat one repetition maximum (1RM) to body mass ratio: 1.65 ± 0.12] performed parallel-depth back squat lifts with 60% of 1RM load at three different speeds: slow fixed-tempo (TS: 2-s eccentric, 1-s pause, 2-s concentric), volitional-speed without a pause (VS) and maximum-speed jump (JS). In each condition joint kinetics, quadriceps tendon length (LT), patellar tendon force (FT) and rate of force development (RFDT) were estimated using integrated ultrasonography, motion-capture and force platform recordings. Results: Peak LT, FT, and RFDT were greater in JS than TS (p

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URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2a20c41e65400a32b9fceb45c85b5b34
https://doi.org/10.3389/fphys.2016.00366

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