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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 < 0.01, [eta]2 = 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.

The inclusion of women canoe in the Olympic Games reflects the growth and development that women have ahead of them in this modality. Therefore, the aim of this study was to explore sex and performance level differences in muscle contractile properties through Tensiomyography (TMG), range of motion (ROM), strength, and canoe-specific functional electromechanical dynamometry (FEMD) performance and establish performance differences between international medalists and non-medalists. Twelve male and nine female canoeists from the Spanish and Portuguese national canoe teams were assessed through TMG, ROM, strength, and canoe-specific isometric and incremental FEMD tests. Few sex and performance level differences were found in TMG and ROM; however, significant sex differences were found in the strength and FEMD tests. Male canoeists had a greater Fmax in Leg Press, Pm and Pmax in canoe position cable row, 1RM bench press and bench pull, Fm and Fpeak canoe-specific isometric FEMD test and number of strokes, and Fpeak and Pmax on the incremental FEMD test than females. International medalists showed a lower time until reaching Vmax and Pmax in Leg Press on both sides and a greater number of strokes and Fpeak in the maximal incremental FEMD test than non-medalists. This study reinforces the utility of the use of TMG and FEMD for assessing and monitoring world-class athletes. [ABSTRACT FROM AUTHOR]

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]

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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]

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]

This work is carried out in order to provide new evidence on the usefulness of the Importance–Performance Analysis (IPA) in the management of golf courses, identifying the main strengths, weaknesses, and discrepancies between managers and users. This information will make it possible to identify potentially mistaken beliefs of managers regarding the service and to design improvement strategies based on the results. The participants were 11 managers, with an average age of 35.4 years (σ 6.5), of whom 72.7% were men and 27.3% were women, and 891 users, with an average age of 47.5 years (σ 12.3), of whom 81.7% were men and 18.3% were women. The instrument used was the Q-Golf scale, and among others, it was applied to the IPA. The results obtained show how the perception of managers regarding the service is worse than that of users. Additionally, the global assessment of the users is higher than the average assessment of each of the items of the club. This positive halo effect, which is not found in the case of managers, is very interesting from the point of view of the loyalty of golf users. [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]

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]

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 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]

The aim of the study was to determine the mechanical and neuromuscular profile of knee extensor and flexor muscles in professional soccer players at the start of the pre-season, and to calculate percentages for symmetry, as well as examine differences according to the player's positional role. The vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF) and biceps femoris (BF) of 16 professional soccer players were evaluated by means of tensiomyography (TMG) on the first day of the pre-season. A paired-samples t test (p < .05) was used to compare the dominant and non-dominant lower limb. One-way ANOVA was applied, with the positional role as an independent factor. No differences were observed between the dominant and non-dominant leg. The highest degree of symmetry corresponded to the VM (92.5 ± 2.7%), and the lowest to the BF (80.7 ± 10.9%). The positional role was associated with significant differences in some of the variables for the BF, RF and VM, although only the half-relaxation time in the BF and the time to sustain force in the VM differed across all the playing positions considered. TMG was shown to be a useful way of evaluating the neuromuscular characteristics of soccer players at the start of the pre-season, and of establishing baseline values for individual players. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the effects of match conditions on the defensive positioning in professional soccer. One hundred and ten ball recovery situations from an elite soccer team were analysed using a tracking system (Amisco Pro). Three team performance variables (ball recovery location (BRL), position of the defensive line (PDL) and position of the offensive line (POL), and three situational variables (match location, quality of opposition and match status) were considered. The results suggest that teams alter their style of play as a consequence of the match conditions. BRL was advanced by 4.87 and 1.80 m (p < 0.05) when the teams were losing and winning, respectively, and POL by 3.67 m (p< 0.05) when losing, than when the scores were even. Playing away decreased the BRL, the PDL and the POL by 4.62, 3.41 and 3.48 m compared with playing at home (p < 0.01). Playing against strong opposition decreased the BRL and the PDL by 5.32 and 3.51 m (p< 0.01) respectively, compared with playing against similar opponents. A combination of these variables can be used to develop a model to predict future performances. The findings emphasise the need for match analysts and coaches to consider the impact of match conditions during assessments of technical and tactical components of football performance. [ABSTRACT FROM PUBLISHER]

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.

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]

Background: This study aimed to determine the optimal time point, either 30 or 60 minutes, at which muscle reactivity to caffeine administration is highest. Unlike previous studies that focused on the nervous system response, we employed tensiomyography (TMG) to directly assess the effects of caffeine on muscle fibers., Methods: TMG measurements were performed on the gastrocnemius medialis muscle of 42 male athletes who regularly consumed caffeine. Participants received a dose of 6 mg/kg body weight and TMG measurements were taken prior to caffeine intake, as well as 30 and 60 minutes afterward., Results: Analysis of TMG parameters including time to contraction (Tc), time delay (Td), and maximal displacement (Dm) revealed that muscles exhibited faster contractions and greater stiffness at the 30-minute mark compared to both pre-caffeine intake and the 60-minute time point. Time exerted a significant main effect on Tc (F(2, 246) = 12.09, p  < .001, ή2p = 0.09), Td (F(2, 246) = 3.39, p  = .035, ή2p = 0.03), and Dm (F(2, 246) = 6.83, p  = .001, ή2p = 0.05), while no significant effect of body side was observed., Conclusions: The findings indicate that muscle contraction time (Tc) and delay time (Td) are influenced by the time elapsed since caffeine ingestion, with the fastest responses occurring after 30 minutes. Additionally, a systemic effect of caffeine was observed, as there were no discernible differences in measurements between the two sides of the body. TMG proves to be an effective noninvasive method for assessing muscle responses following caffeine administration.

Abstract: Iglesias-Caamaño, M, Álvarez-Yates, T, Carballo-López, J, Cuba-Dorado, A, and García-García, O. Interday reliability of a testing battery to assess lateral symmetry and performance in well-trained volleyball players. J Strength Cond Res 36(4): 895-901, 2022-This study aimed to determine the relative and absolute interday reliability of a testing battery for lateral asymmetry detection and performance in well-trained volleyball players and to determine whether retaining for analysis the best or the average value of 3 attempts would modulate the interday reliability and the magnitude of asymmetry. Thirteen Superleague-2 male volleyball players performed on 3 different days a 5-test battery composed of 4 tests for assessing muscle asymmetries: active knee extension, Y-balance test (YBT), modified 20-yard shuttle run (M-20Y), and single-leg countermovement jump; and one for volleyball sports performance: attack jump (AJ). The intraclass correlation index and coefficient of variation (CV) together with the standard error of measurement (SEM, %SEM) and the minimum detectable change (MDC, %MDC) were taken to calculate relative and absolute reliability. Two-way repeated-measures analysis of variance was used to establish the differences between the best value and the average value in each session. The low %MDC (<10%) suggests that all the tests that make up the testing battery would have good sensitivity to detect possible asymmetries. All tests have shown an excellent interday absolute reliability (CV <4.5%; %SEM < 5%), both when retaining the best value and the average value of the 3 attempts. In addition, AJ and YBT (on both legs) obtained a good-excellent relative reliability, whereas the M-20Y test seems to show a lower relative reliability. Retaining the best value or the average value to determine the magnitude and direction of asymmetry seems to be equally reliable with no differences between both values., (Copyright © 2020 National Strength and Conditioning Association.)

Background: The aim of this study was to monitor in-season changes in the mechanical and neuromuscular characteristics of knee extensor and flexor muscles in professional soccer players., Methods: Twenty-one professional soccer players (soccer group, or SG) and sixteen non-soccer playing males (non-soccer group, or NSG) were assessed by tensiomyography on two occasions: just after the start of the competitive season and 10 weeks later. During this time the soccer players' training sessions were built mainly on speed and strength drills. Mixed-design factorial analysis of variance was conducted and effect sizes were calculated., Results: There was a significant interaction between time (assessment points) x group (SG vs. NSG) x muscle for contraction time (Tc), maximum radial muscle displacement (Dm), and delay time (Td). In the case of the knee extensors, after 10 weeks, there was a 17.7%-22.7% decrease in Tc, an 8.7%-9.9% decrease in Td, and a 12.2%-14.2% decrease in Dm knee extensor in the SG (P<0.01), with a large effect size. In the case of the knee flexors, by contrast, there was an 11.9% increase in Td and a 24.5% increase in Dm (P<0.01), with a moderate to large effect size. The findings confirm that mechanical and neuromuscular characteristics change over time and also vary according to the characteristics of the athlete (SG vs. NSG) and the muscle analyzed., Conclusions: In conclusion, soccer coaches could use Tc, Td, and Dm data to individualize work load and intensity and control the effects of neuromuscular training throughout the season using a portable, non-invasive technique that, unlike stress tests, does not cause fatigue and therefore does not interfere with training periodization.