Differences in the Contractile Properties of the Biceps Femoris and Semitendinosus Muscles Throughout a Season in Professional Soccer Players.

The aim of this study was to monitor seasonal changes in the mechanical and neuromuscular characteristics of the knee flexor muscles with tensiomyography, the biceps femoris (BF) and semitendinosus (ST) muscles, of 27 soccer players. All male professional soccer players (age 25 ± 4 years) were measured at the beginning of the preseason (second week) and in the competitive season (10 weeks later). The variables contraction time (Tc) and muscle displacement (Dm) showed significant differences in some muscles, and in others they indicated a tendency to change. In general, the BF improved (more explosive and better muscle tone) and the ST worsened (slower and worse muscle tone) its values during the season. The findings of this study suggest that usual daily soccer training and weekly competition might produce antagonistic changes between the knee flexor muscles.

Relationship of the skin and subcutaneous tissue thickness in the tensiomyography response: a novel ultrasound observational study.

BACKGROUND: The aim of the study was to describe and correlate the skin, subcutaneous tissue, and superficial fascia thickness assessed by ultrasonography (US) with the lumbar erector spinae muscles contractile properties evaluated by tensiomyography (TMG). METHODS: A cross-sectional descriptive study with 50 healthy participants was performed. The point of maximum lordosis in the lumbar region of the right erector spinae was evaluated by US and TMG. First, the skin, subcutaneous tissue, and superficial fascia thicknesses (cm) were assessed by US. Second, the five contractile TMG parameters were analyzed from the right erector spinae muscles belly displacement-time curves: maximal radial displacement (Dm), contraction time (Tc), sustain time (Ts), delay time (Td), and half-relaxation time (Tr). Finally, correlation analyses using Pearson (r for parametric data) and Spearman (rs for non-parametric data) coefficients were performed. RESULTS: A strong negative correlation was shown between Dm and subcutaneous tissue thickness (rs=-0.668; P<.001). Furthermore, moderate negative correlations were observed between Dm and skin thickness (r=-0.329; P=0.020) as well as Tr and subcutaneous tissue thickness (rs=-0.369; P=0.008). The rest of the parameters did not show statistically significant correlations (P >.05). CONCLUSION: Therefore, the lumbar erector spinae contractile properties during TMG assessments, especially Dm and Tr, may be widely correlated by the skin and subcutaneous tissue thickness.

Relationship of the skin and subcutaneous tissue thickness in the tensiomyography response: a novel ultrasound observational study

SUMMARY BACKGROUND: The aim of the study was to describe and correlate the skin, subcutaneous tissue, and superficial fascia thickness assessed by ultrasonography (US) with the lumbar erector spinae muscles contractile properties evaluated by tensiomyography (TMG). METHODS: A cross-sectional descriptive study with 50 healthy participants was performed. The point of maximum lordosis in the lumbar region of the right erector spinae was evaluated by US and TMG. First, the skin, subcutaneous tissue, and superficial fascia thicknesses (cm) were assessed by US. Second, the five contractile TMG parameters were analyzed from the right erector spinae muscles belly displacement-time curves: maximal radial displacement (Dm), contraction time (Tc), sustain time (Ts), delay time (Td), and half-relaxation time (Tr). Finally, correlation analyses using Pearson (r for parametric data) and Spearman (rs for non-parametric data) coefficients were performed. RESULTS: A strong negative correlation was shown between Dm and subcutaneous tissue thickness (rs=-0.668; P<.001). Furthermore, moderate negative correlations were observed between Dm and skin thickness (r=-0.329; P=0.020) as well as Tr and subcutaneous tissue thickness (rs=-0.369; P=0.008). The rest of the parameters did not show statistically significant correlations (P >.05). CONCLUSION: Therefore, the lumbar erector spinae contractile properties during TMG assessments, especially Dm and Tr, may be widely correlated by the skin and subcutaneous tissue thickness.

RESUMO CONTEXTO: O estudo foi elaborado para descrever e correlacionar a pele, o tecido subcutâneo e a espessura da fascia superficial avaliados pelo ultrassom (EUA) com as propriedades contráteis do músculo eretor da coluna lombar avaliadas por tensiomiografia (TMG). MÉTODOS: Foi realizado um estudo descritivo transversal com 50 participantes saudáveis. O ponto de lordose máxima na região lombar da coluna ereta direita foi avaliado pelos EUA e TMG. Primeiro, a pele, o tecido subcutâneo e as espessuras da fáscia superficial (cm) foram avaliadas pelos EUA. Em segundo lugar, os cinco parâmetros TMG contráteis foram analisados a partir das curvas de deslocamento-tempo da barriga do músculo eretor da espinha direita: deslocamento radial máximo (Dm), tempo de contração (Tc), tempo de sustentação (Ts), tempo de atraso (Td) e meio tempo de relaxamento (Tr). Finalmente, foram realizadas análises de correlação usando os coeficientes Pearson (r para dados paramétricos) e Spearman (rs para dados não paramétricos). RESULTADOS: Uma correlação forte negativa foi mostrada entre Dm e espessura subcutânea do tecido (rs = −0,668; P < 0,001). Além disso, foram observadas correlações moderadas negativas entre Dm e espessura da pele (r = −0,329; P = 0,020), bem como a espessura subcutânea do tecido (rs = −0,369; P = 0,008). O restante dos parâmetros não mostrou correlações estatisticamente significativas (P > 0,05). CONCLUSÃO: Portanto, as propriedades contráteis do eretor da espinha lombar durante as avaliações TMG, especialmente Dm e Tr, podem ser amplamente correlacionadas com a pele e a espessura subcutânea do tecido.

Telomere Length in Elite Athletes.

Growing evidence suggests that regular moderate-intensity physical activity is associated with an attenuation of leukocyte telomere length (LTL) shortening. However, more controversy exists regarding higher exercise loads such as those imposed by elite-sport participation. METHODS: The authors investigated LTL differences between young elite athletes (n = 61, 54% men, age [mean ± SD] 27.2 ± 4.9 y) and healthy nonsmoker, physically inactive controls (n = 64, 52% men, 28.9 ± 6.3 y) using analysis of variance (ANOVA). RESULTS: Elite athletes had, on average, higher LTL than control subjects, 0.89 ± 0.26 vs 0.78 ± 0.31, P = .013 for the group effect, with no significant sex (P = .995) or age effect (P = .114). CONCLUSIONS: The results suggest that young elite athletes have longer telomeres than their inactive peers. Further research might assess the LTL of elite athletes of varying ages compared with both age-matched active and inactive individuals.