Baseline Mechanical and Neuromuscular Profile of Knee Extensor and Flexor Muscles in Professional Soccer Players at the Start of the Pre-Season

Abstract

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.

Neuromuscular Characteristic of Biceps Femoris Muscle in the Top Serbian Soccer Players Measured by Tensiomyography Method: Quantitative Model

“…The results obtained in the conducted research coincide with the majority of the results from the previous studies conducted on a sample of international football players (Alvarez-Diaz et al, 2014;García-García, Serrano-Gómez, & Cuba-Dorado, 2014;García-García, Serrano-Gómez, Hernández-Mendo, & Morales-Sánchez, 2017;Gil et al, 2015) in which the authors have also concluded that there are no statistically significant differences in the measured TMG variables BF of the Dom and NonDom leg. Also, very similar descriptive results of the examined variables were obtained on a sample of futsal (Sánchez-Sánchez et al, 2018), volleyball players (Rodríguez-Ruiz et al, 2012) and cyclists (García-García et al, 2013) in regard to the studied BF muscle.…”

“…15.40% vs. 8.13% lower values, for Dom and NonDom leg, respectively), which may suggest a higher level of fatigue of the participants during the testing in the aforementioned study. In a study conducted by García-García et al (2017) the mean values (dominant and non-dominant leg), of the Tc variable, were 34.5±6.6 ms, and for variable Dm they were 7.0±1.7 mm, which is higher by Tc and lower by Dm in relation to our study. One of the possible reasons for the mentioned findings and differences in relation to the results of this study can be explained by an interpretation of testing the sample of football players of a different level of competition, application of tests in a different training period, as well as the size and structure of the sample.…”

Assessment of Skeletal Muscle Contractile Properties by Radial Displacement: The Case for Tensiomyography

“…Vastus lateralis and vastus medialis did, however, display asymmetry with regard to Tc [ 74 ]. A study with a similar population showed less than 10% bilateral asymmetry in vastus medialis and up to about 20% asymmetry in the vastus lateralis, rectus femoris and biceps femoris [ 108 ]. In another study, volleyball players have also shown high levels of displacement symmetry in lower limb muscles, regardless of sex, which is in contrast to the untrained general population [ 50 ].…”

<p>Clinical utility of tensiomyography for muscle function analysis in athletes</p>

“…More and more authors7–9 explicitly state the condition that the evaluator should be an expert, which requires that he has made a good number of measurements and its intra-evaluator reliability is very high.…”