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.

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.

Reference values of tensiomyography (TMG) in professional road cyclists and to examine how the planned periods of the Season produce differences in the muscles: vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF), and to determine how these differences may depend on each cyclist, the assessed muscle, and the side of the body. Ten professional road cyclists (27.5 ± 5.5 years; 178.2 ± 7.8 cm; 65.6 ± 5.46 kg; 72.1 ± 3.7 ml·kg−1·min−1 V[Combining Dot Above]O2; 6 ± 0.4 W·kg−1) were assessed by TMG, in microcycle recovery, at 2 moments of periods during the season: preparation period (PP) and competition period (CP). Student's t contrast for paired groups, Cohen's d effect sizes, and a repeated measures analysis of variance (ANOVA) was applied. We did not find significant differences (p < 0.01) between the lower limbs. The results showed a significantly large increment between the time contraction (TC) values of the PP and CP in the muscles VM (28.7 ± 5.5 vs. 40.6 ± 14.4 milliseconds; 41.4%, p < 0.05, d = 1.1), VL (28.3 ± 4.9 vs. 40.6 ± 10.2 milliseconds; 43.4%, p < 0.05, d = 1.53), and RF (35.9 ± 6.9 vs. 45.9 ± 16.2 milliseconds; 27.8%, p < 0.05, d = 0.8). Nevertheless, TC of the BF presents a significantly large decrease in the CP (35.9 ± 9.9 vs. 28.2 ± 5.2 milliseconds; −21.4%, p < 0.05, d = 0.97). Radial muscle displacement (DM) values are slightly lower during the CP, but the difference is not significant. ANOVA confirmed that these differences depend on the evaluated muscles (TC p = 0.02; DM p = 0.001) and on the cyclists (TC p = 0.001; DM p = 0.001) and does not depend on the side of the body. In conclusion, the TC values during the Season show marked differences between the knee extensors (large increased) and the knee flexor (large decreased). The DM has not changed significantly, keeping the muscular and tendon stiffness....

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.

Background: Providing high-quality chest compressions and rescue breaths are key elements in the effectiveness of cardio­pulmonary resuscitation. Aim: To investigate the effects of a strength training programme on the quality of prolonged basic cardiopulmonary resuscitation on a manikin. Methods: This was a quasi-experimental trial. Thirty-nine participants with prior basic life support knowledge were randomised to an experimental or control group. They then performed a test of 10 min of chest compressions and mouth-to-mouth ventilation on manikins equipped with a skill reporter tool (baseline or test 1). The experimental group participated in a four-week strength training programme focused on the muscles involved in chest compressions. Both groups were subsequently tested again (test 2). Results: After training, the experimental group significantly increased the mean depth of compression (53.7 ± 2.3 mm vs. 49.9 ± 5.9 mm; p = 0.003) and the correct compression fraction (68.2 ± 21.0% vs. 46.4 ± 29.1%; p = 0.004). Trained subjects maintained chest compression quality over time better than the control group. The mean tidal volume delivered was higher in the experimental than in the control group (701.5 ± 187.0 mL vs. 584.8 ± 113.6 mL; p = 0.040) and above the current resuscitation guidelines. In test 2, the percentage of rescue breaths with excessive volume was higher in the experi­mental group than in the controls (31.5 ± 19.6% vs. 15.6 ± 13.0%; p = 0.007). Conclusions: A simple strength training programme has a significant impact on the quality of chest compressions and its maintenance over time. Additional training is needed to avoid over-ventilation of potential patients. Background: Providing high-quality chest compressions and rescue breaths are key elements in the effectiveness of cardio­pulmonary resuscitation. Aim: To investigate the effects of a strength training programme on the quality of prolonged basic cardiopulmonary resuscitation on a manikin. Methods: This was a quasi-experimental trial. Thirty-nine participants with prior basic life support knowledge were randomised to an experimental or control group. They then performed a test of 10 min of chest compressions and mouth-to-mouth ventilation on manikins equipped with a skill reporter tool (baseline or test 1). The experimental group participated in a four-week strength training programme focused on the muscles involved in chest compressions. Both groups were subsequently tested again (test 2). Results: After training, the experimental group significantly increased the mean depth of compression (53.7 ± 2.3 mm vs. 49.9 ± 5.9 mm; p = 0.003) and the correct compression fraction (68.2 ± 21.0% vs. 46.4 ± 29.1%; p = 0.004). Trained subjects maintained chest compression quality over time better than the control group. The mean tidal volume delivered was higher in the experimental than in the control group (701.5 ± 187.0 mL vs. 584.8 ± 113.6 mL; p = 0.040) and above the current resuscitation guidelines. In test 2, the percentage of rescue breaths with excessive volume was higher in the experi­mental group than in the controls (31.5 ± 19.6% vs. 15.6 ± 13.0%; p = 0.007). Conclusions: A simple strength training programme has a significant impact on the quality of chest compressions and its maintenance over time. Additional training is needed to avoid over-ventilation of potential patients.

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.