J Musculoskelet Neuronal Interact
June 2024
Objectives: The aim of this study was to compare torque-velocity profiles, muscle architecture, tendon dimensions, and bilateral-symmetry between competitive cyclists (CY), competitive runners (RN), ice-hockey players (IH), basketball players (BP), and physically-active individuals (CN) (n=10 for each group).
Methods: Vastus lateralis (VL) muscle and patellar tendon (PT) structures were determined with B-mode ultrasonography, and maximal knee extensor isokinetic torque was assessed at three different velocities.
Results: Optimal torque and velocity were lower in runners than CY, BP and IH (p<0.
Purpose: Unaccustomed eccentric contractions generally result in a long-lasting contractile impairment, referred to as prolonged low-frequency force depression (PLFFD), and delayed-onset muscle soreness (DOMS). We here used repeated drop jumps (DJs) as an eccentric contraction model and studied the effects of increasing the time between DJs from 20 s to 5 min. We hypothesized that both PLFFD and DOMS would be less marked at the longer DJ interval due to the longer time to restore structural elements between DJs.
View Article and Find Full Text PDFBackground: Limited and contradictory data are available regarding the acute effects of endurance exercises on cognition and retinal microcirculation. Thus, we aimed to evaluate the acute effects of sport-specific high-intensity interval training (HIIT) on cognition and retinal vessel diameters in experienced amateur boxers.
Methods: Eleven young (age 22.
New Findings: What is the central question of this study? Why do some subjects recover slowly following a bout of eccentric exercise and why is recovery faster following a repeated bout? What is the main finding and its importance? The results are consistent with two major causes of the reduction of quadriceps torque, the onset of low-frequency fatigue which recovered relatively fast and a second, delayed form of damage. Differences in the delayed damage process largely accounted for the differences in the rate of torque recovery between subjects after a first bout and it was suppression of the delayed damage which accounted for the faster recovery following a repeated bout of eccentric exercise.
Abstract: The purpose of this study was to determine the extent to which low-frequency fatigue (LFF) accounts for the loss of quadriceps strength and time course of recovery following a series of drop jumps (DJs).
Background: Although changes in retinal vessel diameter is a new biomarker for the evaluation of cardiovascular risk factors, limited information is available regarding the effects of endurance exercises on retinal microcirculation. Thus, we aimed to evaluate both chronic and acute effects of soccer game on the diameters of retinal vessels in middle-aged players.
Methods: Retinal vessel diameters were measured in 12 middle-aged amateur players (44.
The aim was to assess the effects of sex and age on fatigability and recovery from sustained maximal voluntary contraction (MVC) of the knee extensor muscles. The central (central activation ratio (CAR) and electrical activity amplitude) and peripheral (electrically evoked torque and muscle contractile properties) factors contributing to fatigue and recovery of 24 young adults (12 males) aged 23.2±3.
View Article and Find Full Text PDFVenckunas, T, Snieckus, A, Trinkunas, E, Baranauskiene, N, Solianik, R, Juodsnukis, A, Streckis, V, and Kamandulis, S. Interval running training improves cognitive flexibility and aerobic power of young healthy adults. J Strength Cond Res 30(8): 2114-2121, 2016-The benefits of regular physical exercise may well extend beyond the reduction of chronic diseases risk and augmentation of working capacity, to many other aspects of human well-being, including improved cognitive functioning.
View Article and Find Full Text PDFThe aim of this study was to assess changes in indirect markers of muscle damage and type I collagen degradation, as well as, patellar and Achilles tendon morphological differences during nine daily drop-jumps sessions with constant load alternated with rapid increases in load to test the hypothesis that frequent drop-jump training results in negative muscular and tendon adaptation. Young men (n = 9) performed daily drop jump workouts with progression every 3 days in terms of number of jumps, platform height and squat amplitude. Voluntary and electrically evoked knee extensor torque, muscle soreness, blood plasma creatine kinase (CK) activity and carboxyterminal cross-linked telopeptide (ICTP), patellar and Achilles tendon thickness and cross-sectional area (CSA) were assessed at different time points during the training period and again on days 1, 3, 10 and 17 after the training.
View Article and Find Full Text PDFThere is a lack of data on fatigue changes within 24h among patients with multiple sclerosis. The purpose of this study was to evaluate the effect of time of day on central and peripheral fatigue during a continuous 2-min maximal voluntary contraction of the quadriceps muscle in women and men with multiple sclerosis (MS). We studied age-matched MS patients (range, 40-50years).
View Article and Find Full Text PDFThis study investigated possible differences using the same stretch-shortening exercise (SSE) protocol on generally accepted monitoring markers (dependent variables: changes in creatine kinase, muscle soreness, and voluntary and electrically evoked torque) in males across three lifespan stages (childhood versus adulthood versus old age). The protocol consisted of 100 intermittent (30 s interval between jumps) drop jumps to determine the repeated bout effect (RBE) (first and second bouts performed at a 2-week interval). The results showed that indirect symptoms of exercise-induced muscle damage after SSE were more expressed in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are more resistant to exercise-induced damage than those of adult males.
View Article and Find Full Text PDFThere is a lack of equipment and methods for the reliable and valid measurements of human neuromuscular control. To overcome this limitation, an analyzer of dynamic parameters (DPA-1) of human hand and leg movements was constructed by Kaunas University of Technology and "Katra" engineers in collaboration with the Lithuanian Academy of Physical Education. The aim of the study was to determine the reliability and validity of the tests performed on the DPA-1 in healthy and injured subjects after the anterior cruciate ligament (ACL) reconstruction surgery.
View Article and Find Full Text PDFWe report a technique of an arthroscopic concomitant Bankart repair with a transfer of the coracoid bone block and conjoint tendons for revision anterior shoulder instability. The operative procedure consists of an arthroscopic transfer of the conjoined tendon with a coracoid and arthroscopic Bankart repair. First, a typical Bankart suture anchor procedure with two suture anchors was performed into the antero-inferior part of the glenoid rim.
View Article and Find Full Text PDFObjective: The aim of this study was to evaluate the effect of secondary progressive MS disease on central and peripheral fatigue in women and men during continuous 2-min maximal voluntary contractions (MVC) of the quadriceps muscle.
Methods: We studied age-matched (40-50-years of age) healthy individuals (men, n=9; women, n=10) and MS patients (men, n=9; women, n=9). The inclusion criteria for MS patients were a Kurtzke Expanded Disability Status Score <4 and a Fatigue Severity Scale Score >5.
Int J Sports Med
July 2010
The aim of this study was to investigate the effect of high-intensity plyometric training (PT) on central and peripheral fatigue during exercise performed at maximal intensity in prepubertal boys. The boys (n=13, age 10.3+/-0.
View Article and Find Full Text PDFContext: Whether muscle warming protects against exercise-induced muscle damage is unknown.
Objective: To determine the effect of leg immersion in warm water before stretch-shortening exercise on the time course of indirect markers of exercise-induced muscle damage.
Design: Crossover trial.
Performance in high-intensity exercise is dependent on the ability to activate motor units. The main aim of this study was to test the hypothesis that adult men and women (age 19-27 years) are able to maintain higher levels of voluntary activation (VA) in knee extensor muscles than boys and girls (age 12-14 years). The volunteers (n = 7 in each group) performed three 5-s maximal voluntary contractions (MVCs) and a continuous 2-min MVC.
View Article and Find Full Text PDFUnlabelled: After knee anterior cruciate ligament reconstructive surgery, the recovery of the former level of physical activity takes from 3 to 12 months. Such a wide range of recovery period of physical activity suggests that rehabilitation in most cases is not optimal. According to the majority of authors, after the surgery, a patient can resume intensive physical activity, when the difference in muscle strength between the operated lower extremity and another extremity is not greater than 10-15%.
View Article and Find Full Text PDFThe aim of the study was to establish the dynamics of maximal voluntary contraction force (MVCF), height of drop jump (DJ) and electrically evoked quadriceps muscle force at different stimulation frequencies during and after 100 DJs (stretch-shortening exercise, SSE). Healthy untrained men (n = 11; age = 21.8 ± 1.
View Article and Find Full Text PDFAim: The purpose of this study was to establish the main differences between men (M) and adolescents (A) (males) in metabolic fatigue and damage induced by exercise performed at maximal intensity.
Methods: Healthy A (age 13.4 0.