Search

Purpose: The aim of this study was to determine the changes in neuromuscular contractile properties in elite cyclists associated to the peripheral fatigue produced in a maximal incremental test in cycle ergometer. Methods: Forty-eight volunteers' well-trained male cyclists were evaluated during the competition season within a recovery microcycle. Tensiomyography was used before and after performing an incremental test until exhaustion in cycle ergometer to measure the radial muscle belly displacement of the vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF) on the dominant leg. Maximum radial muscle belly displacement (Dm), contraction time (Tc), delay time (Td), sustain time (Ts), and radial displacement velocity (Vrd) were measured. Mixed-design factorial analysis of variance was used to detect changes in the mechanical and neuromuscular characteristics after a maximal incremental exercise test. Results: The results show in the evaluated muscles a moderate-large decrease (p < .01, η2 = 0.06-0.51) in Tc, Td, Dm, Ts, and Vrd. This decrease occurs more sharply in the BF than in RF or VL. Conclusion: An incremental effort until exhaustion produces peripheral fatigue associated with a decrease in Dm, Tc, Td, Ts, and Vrd, being more pronounced in biceps femoris than in vastus lateralis and rectus femoris. Coaches can use these changes found in the contractile properties as a reference to detect the muscle fatigue degree that certain training models pose for the cyclist. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the acute effect of an 8-week specific hamstring flexibility training on junior canoeist during the competition season. Sixteen canoeists participated, divided into 3 groups: 5 in experimental group 1 (EG1), 5 in experimental group 2 (EG2), and 6 in a control group. The EG1 underwent a supervised program consisted by simple static stretching, dynamic static stretching, and proprioceptive neuromuscular facilitation (PNF), whereas the EG2 performed a program without PNF and no supervision. Two measurements were performed to analyze the effect on the knee joint range of motion (ROM) and trunk flexion; neuromuscular and contractile properties in biceps femoris (BF) and semitendinosus (ST) muscles; and maximum power and average speed in lower limbs. A mixed-design factorial analysis of variance (p ≤ 0.05) was performed and the effect size was calculated. The results show significant improvements (p ≤ 0.05) in both legs for knee joint ROM and trunk flexion in EG1 (8.9 and 25.5%; 5.7 and 20.9% in the right and left leg, respectively) and EG2 (6.7 and 22%; 3.9 and 24.4%), only EG1 improved muscular stiffness in BF (27.4% left leg) and ST (20.5 and 24.3%), and lateral symmetry in BF (49%) without decreasing average speed in lower limbs. All improvements have a large effect size. In conclusion, it is suggested that a supervised hamstring flexibility program performed concurrently during a canoeist competition season can produce an increase in the knee joint ROM and trunk flexion, without negative repercussions in contractile and neuromuscular capacities, maximum power, and average velocity in lower limbs. [ABSTRACT FROM AUTHOR]

The aim was to determine the predictive capacity of neuromuscular parameters on physiological predictors of performance related to pedaling power. The sample comprised fifty elite cyclists. On the same day, they were given a neuromuscular evaluation with tensiomyography (TMG) and then performed an effort test on a cycle ergometer until exhaustion. The TMG recorded the maximum radial muscle belly displacement, contraction time, delay time, derivative normalized response speed, and lateral symmetry. Peak power output (Wpeak · kg - 1), effort time, maximum lactate concentration, power in the first lactate threshold, and power in the second lactate threshold were recorded in the effort test. Linear regression analysis was used to determine the explanatory capacity of neuromuscular parameters on potential cycling performance indicators. A higher Wpeak · kg - 1 during a maximal incremental test on the cycle ergometer can be predicted moderately (R² = 0.683; R²a = 0.615; R = 0.826; Std. Error = 0.26017; p < 0.001) by a longer rectus femoris contraction time and a greater radial muscle belly displacement of the vastus lateralis and vastus medialis as well as a slower normalized response speed of the biceps femoris. In conclusion, neuromuscular parameters can partially explain performance in a specific cycling test until exhaustion. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to explore if specific hip and knee range-of-movement (ROM) tests can predict a risk factor for hamstring strain (HS) injury in male and female soccer players. Methods: One hundred amateur soccer players (56 men and 44 women) performed six tests to determine hip and knee ROM: straight leg raise test (SLR), modified Thomas test (TT), hip internal and external rotation (ER), hip abduction and adduction, Nachlas test and Ridge test. A logistic regression analysis was carried out to create a predictive model for HS injuries. Results: The percentage of HS injury was 20.45% and 30.35%, for female and male players. The logistic regression showed a significant model for both genders on the logit of suffering an HS injury with active-SLR and TT variables for females (R2CS = 0.491; R2N = 0.771) and active SLR and ER variables for males (R2CS = 0.623; R2N = 0.882). The predictive models correctly classify 95.5% and 94.6% of cases presenting good sensitivity (77.8% and 88.2%) and full (100%) and high (97.4%) specificity respectively. Furthermore, female players showed a greater ROM than males (p ≤ 0.01). Conclusion: Both female and male soccer players that suffered a HS injury had lower ROM in SLR, NT and RT and higher ROM in the TT that non-injured players. The tests that most likely predict HS injury are SLR and TT in females and SLR and ER in males. Thus, it is suggested to including specific exercises in amateur soccer players training programs to improve hip and knee ROM for injury prevention. [ABSTRACT FROM AUTHOR]

The article discusses research on the use of tensiomyography (TMG) in assessing neuromuscular profile of top-level female kayakers. Topics explored include the way neuromuscular indicators determine kayaking competition performance, a comparison between the TMG parameters of female and male kayakers, and the use of intraclass correlation coefficient reliabilities in assessing reliability of the TMG parameters of deltoideus, trapezius, and latissimmus dorsi muscles.

The article cites a research study which establishes reference values of tensiomyography (TMG) in professional road cyclists. The study also analyzes how the planned periods of the Season produce differences in the muscles. It is concluded that time contraction (TC) values during the Season show marked differences between the knee extensors and the knee flexor.

The aim of this study is to determine the reliability and generalizability of the data structure from the assessment, through tensiomyography (TMG), the parameters of muscle time contraction (TC) and maximum radial displacement of the muscle belly (DM) of the vastus medialis, vastus lateralis, rectus femoris and biceps femoris muscles of 10 professional road cyclists. TMG measurements took place during the preparatory period and the competitive period. An analysis of variance components by least-squares procedure and maximum likelihood (<.0001), and an analysis of generalizability was performed. The results indicate that the values of error of the variance components analysis by least-squares procedure and maximum likelihood are identical for TC and DM variables, which enables us to consider the sample as normal, linear and homoscedastic. The precision model of the TC variable shows a suitable level of reliability and generalizability (e² = .89 Φ = .83). The model of DM variable shows a suitable level of reliability and a generalizability close to the proper one (e² = .826 Φ = .785). The optimization of the design with the variable TC achieved excellent levels of reliability e² = .94) and generalizability (Φ = .90), as well as the variable DM (e² = .92 Φ = .90). The importance of this work lies in the use of TMG as a primary intervention technique in the prevention of muscle injuries through the calculation of symmetries and their compensation with guaranteed reliability, accuracy and validity. [ABSTRACT FROM AUTHOR]

The article reports on research conducted to detect, describe, and compare two heart rate conditions associated with high intensity efforts during professional soccer games. Researchers evaluated 441 soccer game situations featuring 12 players. They found that a marked increase in heart rate values is associated with active participation in the game and that the maximum heart rate reserve is associated with the end of player participation.

Canoe modality in flatwater canoeing has a clear asymmetrical nature. This study aimed (1) to determine the magnitude and direction of neuromuscular properties, range of motion (ROM) and lower-limb strength asymmetries in female and male canoeists; (2) to establish sex-individualized asymmetry thresholds for canoeists' neuromuscular properties, ROM and lower-limb strength; and (3) to determine the relationship of canoeists' neuromuscular properties, ROM and lower-limb strength asymmetries with a specific canoe–dynamometer performance test. Twenty-one international canoeists were assessed through tensiomyography (TMG), ROM, lower-limb explosive strength, and a specific canoe incremental dynamometric test. The magnitude of asymmetry assessed through TMG and ROM was not modulated either by sex or performance level (international medal vs. non-medal). Females showed greater asymmetry than males on muscle tone of the erector spinae towards non-stroke side (22.75% vs. 9.72%) and the tibialis anterior (30.97% vs. 16.29%), and Fmax in explosive leg press (2.41% vs. 0.63%) towards the stroke side. International medalists showed greater asymmetry in semitendinosus contraction time towards non-stroke side (20.51% vs. 9.43%) and reached Vmax earlier in explosive leg press towards stroke side leg (19.20% vs. 9.40%). A greater asymmetry in Fmax and in Vm, and a smaller asymmetry in Tvmax and in leg press showed a small predictive capacity for canoeists' performance on a specific canoe incremental dynamometry test. Reporting reference data from world-class canoeists' asymmetries can be of great importance for coaches to periodically control lateral asymmetry. [ABSTRACT FROM AUTHOR]

Background/aims: Exercise can be a useful rehabilitation approach for people with lower-limb amputation. However, there is a lack of research in this regard. The aim of this study was to analyse functional mobility, walking speed, range of motion and quality of life changes experienced by people with lower-limb amputation after taking part in a comprehensive exercise programme that included core strengthening exercises. Methods: This was a pilot study including six individuals who carried out a comprehensive exercise programme, which was performed once a week for 5 months. During the first 2 weeks, the participants attended 1-hour sessions that focused on the execution of diaphragmatic breathing and body scheme exercises. From the fourth week until the end of the intervention, the sessions were much longer, and included a warm-up phase, two circuit training workouts for core strength and balance, and a final stretching routine. Results: Significant improvements were found in the participants' functional mobility (P=0.007) and walking speed (P=0.001). The exercise intervention did not have a significant impact on the participants' range of motion and quality of life. Conclusions: In a group of people with lower-limb amputation, the performance of a comprehensive exercise programme that included core strengthening, was found to be beneficial for functional mobility and walking speed, although no significant effect was observed for range of motion and quality of life measures. [ABSTRACT FROM AUTHOR]

This study aimed to determine the neuromuscular changes in muscle contractile properties and countermovement jump (CMJ) performance after a long distance (LD) triathlon, inquiring to what extent it is influenced by gender and the evaluated muscle, and to explore for response differences. Four elite (2 females and 2 males) and 18 well-trained triathletes (3 females and 15 males) who competed in the 2019 LD Triathlon World Championship undergone, prior and post-race, a CMJ and a muscle contractile properties assessment in vastus lateralis (VL) and biceps femoris (BF) using tensiomyography. A mixed ANOVA was carried out to detect triathletes' neuromuscular changes after the competition. A large decrease in jump height and flight time was found in CMJ (p = 0.001, ηp2 = 0.767) with gender differences (ηp2= 0.308). contraction (Tc), delay (Td) and sustain times (Ts) also showed a large decrease (p = 0.001, ηp2= 0.174–0.413). However, maximum radial muscle belly displacement was not altered by the competition, but did greatly increase radial displacement velocity (p = 0.031; ηp2= 0.212). No gender differences were found in contractile properties. Correlation analysis between race performance and the jumping and tensiomyography parameters only showed a moderate negative correlation with Tc of the BF in pre- and post-competition (r = −0.44; −0.43; p = 0.05). In conclusion, triathletes after a LD World Championship suffer a sharp drop in jump performance and variations in VL's and BF's contractile properties, showing decreases in Tc, Td and Ts without gender differences. The regular use of these parameters can allow the monitoring of triathlete's neuromuscular fatigue and aid in the distribution of more efficient loads in their training cycles. Highlights Trainers and researchers in neuromuscular fatigue can have reference data of elite and well-trained triathletes after performing LD race. The magnitude of change in the CMJ and the contractile properties of BF and VL achieved in competition by these elite reference triathletes can guide to modulate triathletes training. The regular use of the parameters using these references can allow an exhaustive neuromuscular fatigue monitoring during the sessions or training cycles throughout the season. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to identify the biomedical signals of short-track athletes by evaluating the effects of monthly strength training on changes in their neuromuscular profile, strength, and power parameters of the lower limb muscles. Muscle asymmetry, which can cause a risk of injury, was also evaluated. Methods and results: This study involved female athletes, age 18.8 ± 2.7 years, with a height of 162 ± 2.4 cm, and weight of 55.9 ± 3.9 kg. Before and after the monthly preparatory period prior to the season, strength measurements were assessed through the Swift SpeedMat platform, and reactivity of the lower limb muscles was assessed with tensiomyography (TMG). The athletes were also tested before and after the recovery training period. In the test after strength training, all average countermovement jump (CMJ) results improved. Flight time showed an increase with a moderate to large effect, using both legs (5.21%). Among the TMG parameters, time contraction (Tc) changed globally with a decrease (-5.20%). Changes in the results of the test after recovery training were most often not significant. Conclusion: A monthly period of strength training changes the neuromuscular profile of short-track female athletes, with no significant differences between the right and left lower limbs. [ABSTRACT FROM AUTHOR]

The assessment of perceived quality has become important in the management of service providing organizations. The aim of this paper is to develop a brief, easy-to-apply scale with appropriate psychometric properties, which allows the incorporation of users' perceptions of the management of golf clubs. We interviewed 403 users of [our 9-hole course golf clubs located in Galicia (316 males and 87 females) aged between 16 and 75 years (Mean = 47.19: SD = 13.91). For data collection, an ad hoc structured questionnaire which had 25 items grouped into 4 dimensions was used. As a result of Exploratory Factor Analysis and a subsequent Confirmatory Factor Analysis, it was possible to obtain a final scale made up of only 15 items, grouped into three dimensions. This scale, as well as being brief and easy-to-apply, has a high degree of validity (as it explains 72% of the perceived performance) and internal consistency (overall ct of .91 ), thus making it a tool of considerable applied interest. [ABSTRACT FROM AUTHOR]

The development of lateral asymmetries in athletes could have an influence on performance or injuries. The aim of this study was to determine the within-day reliability of the symmetry tests and the performance tests, and explore the relationship between them. Eighteen male volleyball players (18.1 ± 2.1 years) participated in this study. Seven lateral symmetry assessments were used, namely: lateral symmetry through tensiomyography (LS), active knee extension (AKE), Y-balance test (YBT), muscular electrical activity in attack jump (MEA-AJ), single-leg squat jump (SLSJ), triple hop test for distance (THTD), and bilateral maximum repetition in leg press (1RMSL); and three volleyball performance tests, namely: the T-test, counter-movement jump (CMJ), and attack jump (AJ). Three in-day measurements were taken from each volleyball player after the recovery was completed. The reliability was calculated through the intraclass correlation coefficient and the coefficient of variation, and the relationship was calculated through Pearson's bivariate correlation coefficient (p < 0.05). The results indicate that AKE, YBT, and LS are the symmetry tests with increased reproducibility. THTD correlates positively with the AKE test and 1RMSL test, and a greater symmetry in the YBT correlates with a greater performance in the CMJ and AJ performance tests. In conclusion, AKE, LS, and YBT are the best tests to determine, with reliability, the asymmetries in volleyball players, and a greater symmetry in the YBT seems to influence the height of bilateral vertical jump. [ABSTRACT FROM AUTHOR]