Acute effects of training load on contractile properties during a competitive microcycle in elite soccer players

The aim of this study was to examine changes in muscle contractile properties across a microcycle of training in professional soccer players during the in-season period. Nineteen professional soccer players were assessed with tensiomyography (TMG) on the biceps femoris and rectus femoris before and after 5 training sessions of an in-season microcycle. Training load was quantified during each training session. Significant differences were observed in training load variables across different training sessions, with the last training session prior to match day showing the lowest values for all training load variables. Significant pre- to post-session increases were observed in muscle stiffness of the rectus femoris and biceps femoris during the first four training sessions (effect size range, 0.5 to 0.9). However, no significant differences were observed in muscle contraction time and contraction velocity from pre- to post-session. In addition, repeated measures correlation analysis revealed significant relationships between absolute change in muscle stiffness of the rectus femoris and training duration, high-speed distance covered during training, and training average distance. The current study shows that players are physically taxed on their muscular stiffness by the training load. Post-session muscular stiffness assessment should be recommended to determine neuromuscular status and readiness in professional soccer players during the competitive season.

Changes in Muscle Contractile Properties after Cold- or Warm-Water Immersion Using Tensiomyography: A Cross-Over Randomised Trial

Muscle contractile properties in clinical practice are often measured using either subjective scales or high-cost, inaccessible equipment. In this randomised cross-over study, we aimed to explore the use of tensiomyography (TMG) to assess changes in muscle contractile properties after cold- and warm-water immersion. The muscle contractile properties of the biceps femoris (BF) were assessed using TMG in 12 healthy active men (mean age 23 ± 3 years, Body Mass Index 22.9 ± 1.3 kg/m²) before and after a 20-min warm- or cold-water immersion over a period of 40 min. Muscle displacement (Dm) and contraction time (Tc) were registered as the main variables of the study. There was a significant condition by time interaction for Dm (p < 0.01). Post hoc analysis showed that, compared to the baseline, there was an increase in Dm 40 min after warm-water immersion (p < 0.01) and a decrease at 10 min after cold-water immersion (p < 0.01). No significant effect was found for Tc. Our results indicate that muscle contractile properties are affected by water temperature and time after the immersion; therefore, these factors should be taken into account when water-immersion is used as a recovery strategy.

Mechanomyographic Measures of Muscle Contractile Properties are Influenced by Electrode Size and Stimulation Pulse Duration

The aim was to determine the effects of changing pulse duration and electrode size on muscle contractile properties. Thirty-six healthy young male participated in the study (age 24.8 ± 5.8 years; height 178.2 ± 0.6 cm; body mass 71.8 ± 7.3 kg; self-reported weekly moderate intensity activity 3.5 ± 1.2 h·week⁻¹). Tensiomyography was used to assess rectus femoris (RF) and vastus medialis (VM) muscles neuromuscular properties of the dominant leg according to the electrode size (3.2–5 cm) and the stimulus length (0.2, 0.5, and 1 ms). Maximal radial displacement (Dm); Contraction time (Tc); Delay time (Td); Sustained time (Ts) and Half relaxation time (Tr) were measured. Relative and absolute reliability was quantified. To analyze the effects of the electrode and the stimulus length, a repeated-measures analysis of variance was used. Dm and Tc parameters showed for both muscles an excellent relative (0.95–0.99) and absolute reliability (1.6–4.2%). However, Ts and Tr showed low values of absolute reliability (4.4–40.9%). The duration of the stimulus length applied to the RF and VM and electrode size significantly influences muscle’s contractile properties (p < 0.05; η²_p = 0.09–0.60). The Dm increases substantially as the duration of the stimulus increases and with the use of the larger electrode in both muscles. However, Tc and Td are less affected by both conditions and not entirely clear. Practically, our study suggests that a stimulus pulse duration of 1 ms together with a 5 × 5 cm electrode is necessary to reach a reliable and reproducible assessment of both RF and VM muscles contractile properties.

Bilateral Asymmetries Assessment in Elite and Sub-Elite Male Futsal Players

This study aimed to investigate morphological, functional, and neuromuscular asymmetries on futsal players’ lower limbs at different competitive levels. Sixteen male elite futsal players from the Spanish National Futsal League and thirteen male sub-elite futsal players from the third division participated in this study. Morphological asymmetry was assessed through bioelectrical impedance (fat-mass (g and %) and lean-mass (g)). Functional asymmetry was assessed by means of a 20-s static unipedal balance test. Finally, neuromuscular asymmetry was assessed using tensiomiography tests on both the rectus femoris (RF) and biceps femoris (BF) of each participant. The three tests conducted did not reveal significant bilateral asymmetries in elite players. On the other hand, sub-elite players showed significant bilateral asymmetry in fat-mass percentage between dominant and non-dominant limbs (+6%; CI95%: 1 to 11; ES: 0.88; p = 0.019). They also showed higher bilateral asymmetry in the delay time of the RF (+13%; CI95%: 7 to 21; ES: 1.3; p < 0.05). However, the static unipedal balance test (p > 0.05) did not evidence asymmetries regardless of the level of the participants. Elite futsal players do not develop bilateral asymmetries in lower limbs in the studied parameters. On the contrary, sub-elite players are likely to develop morphological and neuromuscular asymmetries between their dominant leg and non-dominant leg.

Evolution of contractile properties of the lower limb muscles throughout a season in elite futsal players

BACKGROUND

Futsal is a team sport involving intermittent technical actions of high intensity, and high physical (strength) and muscular demands. In this regard, the tensiomyography (TMG) is a useful and non-invasive tool for the monitoring and assessment of the muscle's contractile capacity. This study aimed to analyze the changes in the contractile properties produced during the season, as well as to determine the potential cumulative effect of a resistance training (RT) program in futsal players.

METHODS

Fourteen elite futsal players (2 goalkeepers, 4 defenders, 4 wingers and 3 pivots) were assessed by TMG at 11th, 18th, and 28th week of the season. The maximal radial displacement of the muscle belly (Dm); contraction time (Tc); delay time (Td) and radial displacement velocity (90%) Dm (VrD90) were assessed. After the second measurement, a RT program was included in the regular training sessions and focused on the lower body musculature. It was performed during 9 weeks (1-weekly). Finally, a third measurement was performed between 28th-29th weeks. Repeated measures analysis of variance was used to detect in-season changes. Two factors were included: Time (changes detected after resistance training program) was used as the within-subject factor and the specific position was used as the between-subject factor.

RESULTS

An increment in Tc for several muscles: biceps femoris (BF; P=0.02), semitendinosus (ST; P=0.04), adductor longus (AL; P=0.008) and gastrocnemius medialis (GM; P=0.009) was observed throughout the season. Similarly, significant increments in Dm for GM (P=0.02) and AL (P=0.05), as well as increments in Td for BF (P=0.002) were found. Moreover, no significant changes in VrD90 between time points 2-3 (analysis of RT effect) were observed. Additionally, the player´s positions reported no significant changes for any of the variables analyzed.

CONCLUSIONS

An increase respect to baseline levels was observed for Tc, Td and Dm during the season. However, the adaptations to contractile properties were muscle specific. In addition, an in-season 9-week RT program (1-weekly), had no significant effects (time points 2-3) on the contractile properties of futsal players. In addition, there were no differences when comparing different positions.

Tensiomyographical responsiveness to peripheral fatigue in quadriceps femoris

Background

Fatigue influences athletic performance and can also increase the risk of injury in sports, and most of the methods to evaluate it require an additional voluntary effort. Tensiomyography (TMG), which uses electrical stimulation and a displacement sensor to evaluate muscle contraction properties of one or more muscle bellies, has emerged as a technique that can assess the presence of peripheral and central fatigue without requiring additional voluntary efforts. However, the evaluation of the TMG’s ability to detect fatigue is limited, both at the level of muscle bellies and statistical methods. Thus, the aim of the present study was twofold: (i) to examine and compare the tensiomyographical responsiveness to quadriceps femoris (QF) fatigue by multiple statistical methods and (ii) to analyze sex differences in the variation produced by fatigue in TMG parameters.

Methods

Thirty-nine recreational athletes participated (19 males/20 females; aged 22 ± 2 years). TMG parameters of QF bellies and maximal voluntary isometric contraction (MVIC) were measured before and after a fatigue protocol. TMG parameters used were maximum radial deformation (Dm), contraction time between 10–90% of the Dm (Tc), contraction velocity between 10–90% (Vc) and of the first 10% (V10) of the Dm. Internal responsiveness of TMG to fatigue was analyzed by paired t-test and standardized response mean (SRM). External responsiveness was examined by correlations, regression models, and receiver operating characteristic (ROC) curves.

Results

All TMG parameters, except for Tc of rectus femoris and vastus medialis, showed large internal responsiveness. In adjusted regression models by sex, only Dm and V10 of rectus femoris were statistically associated (p < 0.05) with b coefficients of 0.40 and 0.43, respectively. r2 explained the 22% of the total variance. In addition, these parameters could discriminate between QF with and without fatigue.

Conclusion

Since the QF is the main strength contributor during multiple physical activities, clinicians and trainers will be able to discriminate the presence of fatigue and the magnitude of changes in the QF strength by TMG evaluation.

Effects of a Multi-ingredient Beverage on Recovery of Contractile Properties, Performance, and Muscle Soreness After Hard Resistance Training Sessions

Naclerio, F, Larumbe-Zabala, E, Cooper, K, and Seijo, M. Effects of a multi-ingredient beverage on recovery of contractile properties, performance, and muscle soreness after hard resistance training sessions. J Strength Cond Res 34(7): 1884-1893, 2020-Carbohydrate-protein-based supplements have been proposed for maximizing postexercise recovery. This study compared the effects of postworkout supplementation ingesting a multi-ingredient (MTN) vs. carbohydrate alone (CHO) on the recovery of muscle function and perceived of delayed onset of muscle soreness (DOMS) after hard resistance workouts. In a double-blinded, crossover design, 10 resistance trained men (26.9 ± 7.4 years) performed 2 identical 5-day intervention periods while ingesting either MTN or CHO. The subjects performed one workout per day during the first 3 days. Thereafter, they were assessed 1, 24, and 48 hours after the completion of the third workout session. Primary outcome was tensiomyography (muscle displacement [Dm], contraction time [Tc], and contraction velocity [Vc]) of the vastus medialis (VM) and biceps femoris long head (BFLH). Secondary outcomes were performance and DOMS. At 24 hours, both conditions decreased (p < 0.05) Dm (MTN -1.71 ± 1.8, CHO -1.58 ± 1.46 mm) and Vc (MTN -0.03 ± 0.03, CHO 0.03 ± 0.04 m·s) in the VM. At 48 hours, all tensiomyography variables were recovered under the MTN while remained depressed (p < 0.01) in CHO (VM, Dm 1.61 ± 1.60, Vc -0.04 ± 0.04 m·s; BFLH, Dm 1.54 ± 1.52, Vc -0.02 ± 0.02 m·s). Vertical jump performance decreased in CHO, but not in MTN. Although both conditions decreased upper-body strength and power at 1 hour, values returned to baseline in 24 hours for MTM while needed 48 hours in CHO. DOMS similarly increased at both 24 and 48 hours in both conditions. Compared with the ingestion of only carbohydrates, postworkout multi-ingredient supplementation seems to hasten recovery of muscular contractile properties and performance without attenuating DOMS after hard resistance workouts.

The effect of inter-electrode distance on radial muscle displacement and contraction time of the biceps femoris, gastrocnemius medialis and biceps brachii, using tensiomyography in healthy participants

BACKGROUND

The systematic effect of inter-electrode distance on electrically elicited radial muscle displacement (Dm) and contraction time (T _c) of the biceps femoris, gastrocnemius medialis and biceps brachii using tensiomyography (TMG) is currently unavailable.

OBJECTIVE

To investigate the effects of inter-electrode distance (4 cm, 5 cm, 6 cm and 7 cm) on Dm and T _c of the biceps femoris, gastrocnemius medialis and biceps brachii, when the current amplitude is standardised.

APPROACH

A within subject, repeated measures cross-over study.

PARTICIPANTS

24 participants.

MAIN RESULTS

Biceps femoris and gastrocnemius medialis Dm increased with increased inter-electrode distance (biceps femoris: p   =  0.015; gastrocnemius medialis: p   =  0.000), yet T _c were not affected (p   >  0.05). Biceps brachii Dm was not affected by inter-electrode distance (p   >  0.05), yet T _c became shorter with increased inter-electrode distance (p   =  0.032).

SIGNIFICANCE

Inter-electrode distance affects Dm but not T _c in two pennate muscles (biceps femoris and gastrocnemius medialis), and T _c but not Dm in one parallel muscle (biceps brachii). Based on Dm measurements, optimal muscle specific inter-electrode distances were judged within the limits of this study. The following optimal inter-electrode distances are suggested: biceps femoris  =  6 cm, gastrocnemius medialis  =  7 cm and biceps brachii  =  4 cm. Our findings emphasise the importance of accurate implementation and reporting of inter-electrode distance, for the reproducibility and comparability of studies using TMG.

Clinical utility of tensiomyography for muscle function analysis in athletes

An exhaustive review has been made to filter the studies that have analyzed muscle function though tensiomyography (TMG) with elite or well-trained athletes. The results of this review indicate that the several protocols used in athletes to find the displacement-time curve with greater maximum radial muscle displacement showed a good-excellent reliability. TMG has been used to characterize athletes' muscles contractile properties from specific sports disciplines, although there are very few sports that have been deeply analyzed. TMG seems to be useful to determine changes in muscles contractile properties after stimuli of competition, training or recovery. These changes have been strongly related with the fatigue produced after an effort. In addition, TMG parameters could be used to control training effects during a specific period or throughout the season being also a very useful tool to individualize athletes training loads. In this sense, it also seems to provide sports performance information in cyclic sports by relating some TMG parameters with performance indicators. On the other hand, the TMG-BCM algorithm has been used as a lateral and functional symmetry measure and as a monitoring tool for injury prevention and recovery. However, it seems to be no clear criterion that determines asymmetry degree, nor established contractile properties values as a reference to prevent or recover sports injuries. Despite the utility shown in these fields, there are still very few sports analyzed and it is really necessary to continue advancing in the knowledge of the contractile properties behavior, such as the effects of athletes' training, competitions and injuries and even in the parameters interpretation obtained with the TMG.

Test-retest reliability of elbow flexor contraction characteristics with tensiomyography for different elbow joint angles

Tensiomyography (TMG) has gained popularity as a tool to quantify muscle contractile properties. However, it is unclear whether joint angle and inter-stimulus interval influence the test-retest reliability of TMG. Fifteen participants (13M/2F; 29.5 ± 7.4 y) underwent TMG recording of the biceps brachii (BB) at 10°, 45° and 90° of elbow flexion with 10 and 20 s inter-stimulus rest intervals in a randomised order on two separate days. The intra-class correlation coefficient (ICC_2,1) and 95% confidence interval (95%CI) were calculated for delay time (Td), contraction time (Tc), sustain time (Ts), relaxation time (Tr) and maximal displacement (Dm). Additionally, the standard error of measurement (SEM), coefficient of variation (CV) and minimal detectable change (MDC) were obtained. Across conditions the ICC_2,1 varied for each parameter (Td:0.465-0.947, Tc:0.452-0.831, Ts:0.717-0.918, Tr:0.841-0.935, Dm:0.646-0.900). CV was low for Td (2.1-3.0%), Tc (4.4-7.7%) and Ts (5.5-6.9%) but greater for Tr (10.0-15.3%) and Dm (5.8-13.1%) across conditions. Ts (∼210 ms, P < 0.001) and Dm (∼17 mm, P < 0.001) were greatest at 10° and 90°, respectively, while Td was shortest (∼22.9 ms, P = 0.002) at 10° compared to other angles. No differences were observed between inter-stimulus intervals or day. The findings are expected to help shape best practice methods for TMG use in field and research based settings.

Effects of moderate vs. high iso-inertial loads on power, velocity, work and hamstring contractile function after flywheel resistance exercise

Flywheel iso-inertial training has been shown to positively affect muscular strength and sports performance (e.g. agility). However, implementing such eccentrically-biased training during a microcycle needs to be carefully planned due to its purported effects on the neuromuscular system that can last for hours/days post-exercise. This study aimed at using tensiomyography to verify the effects of different inertias during the hip extension exercise on the contractile function of biceps femoris and semitendinosus muscles of the dominant leg for up to 72 hours post-exercise. Thirty participants (24.4 ± 3.4 years) were divided into 0.075 or 0.1 kg·m2 inertia groups and a control group. Magnitude-based analysis was used for the comparisons. Several tensiomyography parameters were changed after both intensities of flywheel exercise (in most cases indicating a decrement in muscle stiffness), whereas most between-group differences suggested that in the semitendinosus muscle, the higher inertia (0.1 kg·m2) influenced the muscle stiffness parameters more (e.g. Dm = maximal radial displacement) while in the biceps femoris, the greater effect was caused by the lower inertia (0.075 kg·m2) (e.g. Tc = contraction time). Most changes in contractile properties of the investigated muscles occur within 24 hours post-exercise, but can persist for up to 72 hours. However, higher inertia (0.1 kg·m2) influenced the stiffness of the semitendinosus muscle more, while in the biceps femoris, the greater effect was caused by the lower inertia (0.075 kg·m2). These findings should be considered by practitioners when prescribing flywheel iso-inertial training.

Localization of Muscle Edema and Changes on Muscle Contractility After Dry Needling of Latent Trigger Points in the Gastrocnemius Muscle

In this article, we aimed to describe what happens in skeletal muscle after dry needling intervention using magnetic resonance imaging (to show if there is edema) and tensiomyography (to measure contractile properties). At the same time, we describe the relationship between pain, edema, and contractility. Our results suggest that in asymptomatic patients, the application of dry needling over latent trigger points produce intra-muscular edema, an increase in muscle stiffness and an improved muscle contraction time.

Effect of a Repeated Sprint Ability test on the muscle contractile properties in elite futsal players

The aim of this study was to evaluate the effect of a repeated sprint ability (RSA) test on the contractile properties of the muscles in elite futsal players. A total of 20 elite players completed the RSA test (7 × 30 m), and the contractile response from the rectus femoris (RF) and biceps femoris (BF) of both legs were analysed pre and post through tensiomyography. There was a significant increment in 30-m times from the third sprint onwards (p < 0.05). The percent decrement in sprint ability (RSA_DEC) with respect to the first sprint was significantly higher in the last sprint. The players did not show evidence of lateral asymmetry in any of the muscle groups analysed after the RSA test (p > 0.05). Following the RSA test there was a significant reduction in the delay time (Td) in RF, a significant decrement in half-relaxation time (Tr) in the RF, and a significant reduction in sustain time (Ts) in the RF and BF of both legs. The maximum radial displacement of the muscle belly (Dm) increased (1.6 mm; effect size = 0.75; p < 0.05) in the RF after the RSA test, indicating reduced muscle stiffness and the ability to generate strength rapidly. The decrement in performance during the RSA test was significantly correlated with changes in contraction time (Tc) in RF and BF, Td in BF, and Dm in RF (p < 0.05). The RSA test generated alterations in the contractile properties of the RF and BF in elite players. However, futsal players did not present asymmetries in any muscular parameters. The baseline contractile muscle parameters could be an important factor related to performance of players during repeated high-intensity actions.

Intrasession Reliability of the Tests to Determine Lateral Asymmetry and Performance in Volleyball Players

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.

Change in skeletal muscle stiffness after running competition is dependent on both running distance and recovery time: a pilot study

Long-distance running competitions impose a large amount of mechanical loading and strain leading to muscle edema and delayed onset muscle soreness (DOMS). Damage to various muscle fibers, metabolic impairments and fatigue have been linked to explain how DOMS impairs muscle function. Disruptions of muscle fiber during DOMS exacerbated by exercise have been shown to change muscle mechanical properties. The objective of this study is to quantify changes in mechanical properties of different muscles in the thigh and lower leg as function of running distance and time after competition. A custom implementation of Focused Comb-Push Ultrasound Shear Elastography (F-CUSE) method was used to evaluate shear modulus in runners before and after a race. Twenty-two healthy individuals (age: 23 ± 5 years) were recruited using convenience sampling and split into three race categories: short distance (nine subjects, 3–5 miles), middle distance (10 subjects, 10–13 miles), and long distance (three subjects, 26+ miles). Shear Wave Elastography (SWE) measurements were taken on both legs of each subject on the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), soleus, lateral gastrocnemius (LG), medial gastrocnemius (MG), biceps femoris (BF) and semitendinosus (ST) muscles. For statistical analyses, a linear mixed model was used, with recovery time and running distance as fixed variables, while shear modulus was used as the dependent variable. Recovery time had a significant effect on the soleus (p = 0.05), while running distance had considerable effect on the biceps femoris (p = 0.02), vastus lateralis (p < 0.01) and semitendinosus muscles (p = 0.02). Sixty-seven percent of muscles exhibited a decreasing stiffness trend from before competition to immediately after competition. The preliminary results suggest that SWE could potentially be used to quantify changes of muscle mechanical properties as a way for measuring recovery procedures for runners.

Relationship between skeletal muscle contractile properties and power production capacity in female Olympic rugby players

This study aimed to determine which contractile properties measured by tensiomyography (TMG) could better differentiate athletes with high- and low-power values, as well as to analyse the relationship between contractile properties and power production capacity. The contractile properties of the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) of an Olympic women's Rugby Sevens team (n = 14) were analysed before a Wingate test in which their peak power output (PPO) was determined. Athletes were then divided into a high-power (HP) and a low-power (LP) group. HP presented an almost certainly higher PPO (9.8 ± 0.3 vs. 8.9 ± 0.4 W kg^-1, ES = 3.00) than LP, as well as a very likely lower radial displacement (3.39 ± 1.16 vs. 5.65 ± 1.50 mm, ES = 1.68) and velocity of deformation (0.08 ± 0.02 vs. 0.13 ± 0.03 mm ms^-1, ES = 1.87) of the VL. A likely lower time of delay was observed in HP for all analysed muscles (ES > 0.60). PPO was very largely related to the radial displacement (r = -0.75, 90% CI = -0.90 to -0.44) and velocity of deformation (r = -0.70, 90% CI = -0.87 to -0.34) of the VL. A large correlation was found between PPO and the time of delay of the VL (r = -0.61, 90% CI = -0.84 to -0.22). No correlations were found for the contractile properties of RF or VM. These results highlight the importance of VL contractile properties (but not so much those of RF and VM) for maximal power production and suggest TMG as a practical technique for its evaluation.