The aim of our study was to assess eccentric-exercise-induced changes in passive knee joint torque, passive knee joint stiffness and shear modulus at of the hamstring muscles. We hypothesized that eccentric exercise would elicit an increase in all outcomes. Fourteen healthy volunteers (age = 25.5±4.7 years) performed eccentric exercise protocol. Before and after 0h, 1h, 24h and 48h, we measured the shear modulus of hamstring muscles using shear-wave elastography and passive knee joint stiffness on isokinetic dynamometer. After eccentric exercise, the shear modulus of biceps femoris increased after 0h (22.4 ± 34.1 %; p = 0.021) and for semitendinosus after 0h (14.5 ± 4.9 %), 1h (16.2 ± 6.5 %) and 24h (16.6 ± 8.3 %) (p = 0.005-0.015). There were no changes for semimembranosus and no changes in passive knee joint moment measures. There were also no correlations between the two methods. Eccentric exercise increased shear modulus of hamstring muscles, while passive joint torque was not affected. This suggests that shear-wave elastography could be more sensitive than torque measures to intra-muscular changes induced by eccentric exercise.
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http://dx.doi.org/10.4081/ejtm.2022.10567 | DOI Listing |
Med Sci Sports Exerc
December 2024
Department of Rehabilitation Sciences, Ghent University, Ghent, BELGIUM.
Purpose: Eccentric calf training for Achilles tendinopathy shows variable success in athletes. Recent insights suggest a role for tendon fluid flow (exudation or redistribution) during exercise, which explains post-exercise reductions in thickness and increases in stiffness of the tendon. This fluid flow is thought to be beneficial as it may promote tendon remodeling, reduce intratendinous pressure, and alleviate pain.
View Article and Find Full Text PDFSci Rep
January 2025
Human Movement Biomechanics Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium.
The treatment of Achilles tendinopathy is challenging, as 40% of patients do not respond to existing rehabilitation protocols. These protocols neglect individual Achilles tendon (AT) characteristics, which are crucial for healing of the tendon tissue. Although prior studies suggest an optimal strain for AT regeneration (6% tendon strains), it is unclear if current protocols meet this condition.
View Article and Find Full Text PDFNutrients
December 2024
School of Sport, Exercise & Nutrition, College of Health, Massey University, Palmerston North 4410, New Zealand.
Background: Consuming collagen hydrolysate (CH) may improve symptoms of exercise-induced muscle damage (EIMD); however, its acute effects have not been compared to dairy protein (DP), the most commonly consumed form of protein supplement. Therefore, this study compared the effects of CH and DP on recovery from EIMD.
Methods: Thirty-three males consumed either CH ( = 11) or DP ( = 11), containing 25 g of protein, or an isoenergetic placebo ( = 11) immediately post-exercise and once daily for three days.
Eur J Sport Sci
January 2025
Nutrition and Sports Performance Research Group, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland.
This study aimed to investigate the effects of performing either eccentric-only (ECC) or eccentric-concentric (ECC-CON) back squats (BS) with a supramaximal load on countermovement jump (CMJ) performance. Changes in front thigh skin surface temperature and mechanical properties (oscillation frequency and stiffness) of the vastus lateralis were also examined. Fourteen male powerlifters participated in this study (age: 22.
View Article and Find Full Text PDFEur J Appl Physiol
December 2024
LFE Research Group, Department of Health and Human Performance. Faculty of Physical Activity and Sport Sciences, Universidad Politécnica de Madrid, Calle de Martín Fierro, 7, 28040, Madrid, Spain.
Purpose: To investigate the acute effects of eccentric-based resistance exercise and sex-hormone fluctuations on P1NP and β-CTX-1 concentrations in premenopausal females.
Methods: Nine eumenorrheic females and ten oral contraceptive (OC) users performed eccentric-based resistance exercise, consisted of 10 × 10 repetitions of parallel back squats with a 4-s eccentric phase, in the early-follicular (EFP), late-follicular (LFP) and mid-luteal (MLP) phases of the menstrual cycle (MC) or in the withdrawal (WP) and active pill-taking (APP) phases of the OC cycle.
Results: 17β-oestradiol (pg·ml) was lower in EFP (36.
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