scholarly journals Correlation between strength and flexibility of knee flexors and extensors muscles in youth soccer players

2020 ◽  
pp. 1-5
Author(s):  
Maira Peloggia Cursino ◽  
Ana Elisa Zulliani Stroppa Marques ◽  
Hugo Castellon Quatrochi ◽  
Flavia Roberta Faganello Navega ◽  
Cristiane Rodrigues Pedroni
Keyword(s):  
Muscle Strength ◽  
Significant Positive Correlation ◽  
Soccer Players ◽  
Muscle Injuries ◽  
Flexor Muscle ◽  
Positive Correlation ◽  
Youth Soccer ◽  
Knee Flexor ◽  
H:Q Ratio ◽  
The Right

Introduction: Soccer is the most played sport in the world and the one that causes more injuries. Imbalance between knee flexor and extensor is the main cause of muscle injuries in soccer players. Objective: The aim of this study was to verify the asymmetry and the correlation between the strength and flexibility of knee flexor and extensor as well as the difference of these variables between the right and left limbs in youth soccer players. Method: The sample consisted of 45 male youth soccer players for at least a year, aged between 13 and 16 years (14.7+0.86). The athletes underwent an assessment of flexibility of the posterior chain through the sit and reach test on Wells’ Bench and an assessment of flexibility of the quadriceps using the Ely’s test, with measurement of passive range of motion by goniometry. The peak of muscle strength was measured using a load cell (EMG  System, Brazil). Results: Data analysis showed difference between the values obtained in the Ely’s test of right and left leg (p=0,03), which did not happen for flexion strength (p=0.45), extension (p=0.41) and H:Q ratio (p = 0.40) when comparing the two members. It was observed a significant negative correlation between the H:Q ratio and the flexibility of the posterior chain test either for the right side (r=-0.40; p=0.006) or left side (r=-0.50; p=0.0004). Also a significant positive correlation was observed between quadriceps strength and flexibility of the posterior chain, both for the right (r=0.31; p=0.03) and the left side (r=0.32; p=0.02). Just for the left side a significant positive correlation was observed when compared the flexor muscle strength with the flexibility of the quadriceps (r=0.30; p=0.03). Conclusion: We conclude from this study that the flexibility of the posterior chain may be related to the strength of the antagonists, however, when the two physical qualities were compared in the same muscles, it showed no correlation.

Isokinetic Strength After ACL Reconstruction: Influence of Concomitant Anterolateral Ligament Reconstruction

2021 ◽  
pp. 194173812110054
Author(s):  
Benoit Gillet ◽  
Yoann Blache ◽  
Isabelle Rogowski ◽  
Grégory Vigne ◽  
Bertrand Sonnery-Cottet ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Ligament Reconstruction ◽  
Knee Extensor ◽  
Anterolateral Ligament ◽  
Flexor Muscle ◽  
Knee Flexor ◽  
Strength Recovery ◽  
Flexor Muscles ◽  
Knee Muscle ◽  
Knee Muscle Strength

Background: To reduce the rate of anterior cruciate ligament (ACL) graft rupture, recent surgeries have involved anterolateral ligament reconstruction (ALLR). This reconstruction procedure harvests more knee flexor muscle tendons than isolated ACL reconstruction (ACLR), but its influence on knee muscle strength recovery remains unknown. This study aimed to assess the influence of ALLR with a gracilis graft on the strength of the knee extensor and flexor muscles at 6 months postoperatively. Hypothesis: The additional amount of knee flexor harvest for ALLR would result in impairment in knee flexor muscle strength at 6 months postoperatively. Study Design: Retrospective cohort study. Level of Evidence: Level 2. Methods: A total of 186 patients were assigned to 2 groups according to the type of surgery: ACL + ALLR (graft: semitendinosus + gracilis, n = 119) or isolated ACLR (graft: semitendinosus, n = 67). The strength of the knee extensor and flexor muscles was assessed using an isokinetic dynamometer at 90, 180, and 240 deg/s for concentric and 30 deg/s for eccentric contractions and compared between groups using analysis of variance statistical parametric mapping. Results: Regardless of the surgery and the muscle, the injured leg produced significantly less strength than the uninjured leg throughout knee flexion and extension from 30° to 90° for each angular velocity (30, 90, 180, and 240 deg/s). However, the knee muscle strength was similar between the ACL + ALLR and ACLR groups. Conclusion: The addition of ALLR using the gracilis tendon during ACLR does not alter the muscle recovery observed at 6 months postoperatively. Clinical Relevance: Although more knee flexor muscle tendons were harvested in ACL + ALLR, the postoperative strength recovery was similar to that of isolated ACLR.

scholarly journals Genética y fútbol: asociación de los polimorfismos genéticos ACTN3 y ACE-I/D en jugadores de fútbol: Revisión literaria (Genetic and soccer: association of ACTN3 and ACE-I/D genetic polymorphisms in soccer players: Literary review)

Retos ◽  
2020 ◽  
Author(s):  
Wilson Arroyo Moya
Keyword(s):  
Genetic Polymorphisms ◽  
Soccer Players ◽  
Muscle Injuries ◽  
Physiological Level ◽  
Youth Soccer ◽  
Genotypic Combination ◽  
Genetic Components ◽  
Professional Soccer ◽  
Hereditary Factors ◽  
And Performance

  Se ha comprobado y establecido que alrededor del 66% de los componentes del rendimiento y estado del atleta se explican por los factores hereditarios. Dos de los polimorfismos genéticos mas estudiados con relación al rendimiento deportivo en la ultima década, son el ACTN3 R577X y el ACE I/D. El objetivo de este estudio fue resumir las posibles asociaciones de ambos polimorfismos y el rendimiento en jugadores de fútbol, determinando la combinación alélica y genotípica que más destaca en esta población y, además, observar las relaciones de estos a nivel físico y fisiológico. Para la realización de este estudio se llevaron a cabo dos fases, una primera de revisión bibliográfica y una segunda fase de clasificación y análisis de la información. Los estudios evidencian una mayor influencia de los alelos ACE-D y ACTN-R, y de los genotipos ACE-ID y ACTN-RR. Se observó que los sujetos con estas combinaciones tenían mejores rendimientos es pruebas de velocidad y fuerza. Por otro lado, el polimorfismo ACTN3 está directamente relacionado con las lesiones musculares. En conclusión, se pudo observar una relación entre los polimorfismos genéticos y el rendimiento en jugadores de fútbol. Los componentes genéticos se pueden integrar como un nuevo componente dentro de la caracterización del deporte y como una herramienta dentro de un modelo de identificacción y detección de talentos en el fútbol juvenil. Además, los biomarcadores genéticos podrían ser responsables en un futuro, del estudio del riesgo de lesiones para que se optimice mucho más el rendimiento en el fútbol profesional. Abstract. It has been verified and established that around 66% of the components of the athlete's performance and state are explained by hereditary factors. Two of the most studied genetic polymorphisms in relation to sports performance in the last decade are ACTN3 R577X and ACE I/D. The aim of this study was to summarize the possible associations of both polymorphisms and the performance in soccer players, determining the allelic and genotypic combination that stands out the most in this population and, also, to observe their relationships at the physical and physiological level. In order to complete this study, two phases were carried out, the first one of literature review and, the second one which covered the information classification and analysis. The studies show a greater influence of the ACE-D and ACTN-R alleles, and higher presence of the ACE-ID and ACTN-RR genotypes. Subjects with these combinations were found to perform better on speed and strength tests. On the other hand, the ACTN3 polymorphism is directly related to muscle injuries. In conclusion, a relationship between genetic polymorphisms and performance in soccer players could be observed. Genetic components can be integrated as a new component within the characterization of sport and as a tool within a model of identification and detection of talents in youth soccer. In addition, genetic biomarkers could be responsible, in the future, for the study of the risk of injury so that performance in professional soccer is much more optimized.

Hamstring Flexibility Is Not Correlated with Isokinetic Knee Muscle Strength in Female Modern Dancers

2018 ◽  
Vol 33 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Ani Agopyan
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Flexor Muscle ◽  
Work Production ◽  
University Level ◽  
Modern Dancers ◽  
Hamstring Flexibility ◽  
Knee Muscle ◽  
The Right

OBJECTIVE: To evaluate bilateral isokinetic knee extensor and flexor muscle strength relative to hamstring flexibility in female modern dancers. METHODS: 20 trained university-level female modern dance students (mean age 23.8±3.8 yrs) volunteered for the study. Concentric isokinetic peak torque (PT, in Nm), peak torque % of body weight (PT%BW, in Nm/kg), and total work (TW, in J) of the knee extensor and flexor muscles for each leg were measured with a dynamometer at a velocity of 60, 180, and 300°/s. Hamstring flexibility of both limbs was assessed by a goniometer with the subjects in a supine position using the active straight leg raise (SLR) test. Participants were divided into flexible (n=10) and highly flexible (n=10) groups based on their hamstring flexibility. RESULTS: The flexible and highly flexible groups had significant differences (p≤0.05) for the right (flexible, 119.7±4.3°; highly flexible, 137.7±2.6°) and left active SLR tests (flexible, 120.6±5.3°; highly flexible, 138.3±4.5°). No significant differences were found between the flexible and highly flexible dancers for concentric knee extensor and flexor muscle strength in all selected parameters (p≤0.05). There were also no significant correlations between flexibility and bilateral PT, PT%BW, and TW scores (60, 180, and 300°/s) of dancers at the concentric contraction (p≤0.05). CONCLUSION: These findings indicate that hamstring flexibility (for both the flexible and highly flexible groups) is not correlated with knee strength and has no impact on torque and work production during maximal concentric isokinetic knee muscle action in university-level female modern dancers.

scholarly journals Evaluating injury risk in first and second league professional Portuguese soccer: muscular strength and asymmetry

2016 ◽  
Vol 51 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Alberto Carvalho ◽  
Scott Brown ◽  
Eduardo Abade
Keyword(s):  
Muscle Strength ◽  
Injury Risk ◽  
Dynamic Control ◽  
Peak Torque ◽  
Soccer Players ◽  
Bilateral Asymmetry ◽  
Hamstring Strain ◽  
Professional Soccer ◽  
Maximal Peak ◽  
The Right

AbstractStrength imbalances between the hamstrings and quadriceps are an essential predictor for hamstring strain in soccer. The study aimed to investigate and compare the muscle strength imbalances of professional soccer players of different performance levels. One hundred and fifty nine senior male professional soccer players from first (n = 75) and second league (n = 84) Portuguese clubs participated in this study. Muscle strength was evaluated with a REV9000 isokinetic dynamometer. Maximal peak torque data were used to calculate quadriceps and hamstrings strength during concentric and eccentric actions, bilateral asymmetry, conventional strength ratios and dynamic control ratios. Second league athletes produced slightly lower conventional strength ratios in the right and left legs (ES = 0.22, p = 0.17 and ES = 0.36, p = 0.023, respectively) compared to the first league athletes. No significant differences were found in dynamic control ratios or in bilateral asymmetry among first and second league athletes. These findings do not show a clear link between the competitive level and injury risk in soccer players. However, some of the differences found, particularly in conventional strength ratios, highlight the importance of performing off-season and pre-season strength assessments to prescribe and adjust individual strength training programs among professional soccer players.

scholarly journals The second to fourth digit ratio: a measure of hand grip strength?

2017 ◽  
Vol 4 (5) ◽  
pp. 1250 ◽  
Author(s):  
Bijli Nanda ◽  
Prajna Paramita Samanta
Keyword(s):  
Grip Strength ◽  
Significant Positive Correlation ◽  
Ring Finger ◽  
Hand Grip Strength ◽  
Positive Correlation ◽  
Left Hand ◽  
Hand Grip ◽  
Physical Abilities ◽  
Scanned Images ◽  
The Right

Background: The ratio of the lengths of the index and the ring finger (2D:4D ratio) is generally different between men and women. This has often been used as an indicator of the levels of prenatal androgen exposure. It has hence been suggested to have a role in many gender differences including performance in sports. Men generally outperform women in most physical abilities. However, reports in various studies have been inconclusive, depending upon the physical ability tested. Hand Grip Strength (HGS) is a good measure of overall strength of an individual. Hence, we decided to determine the relationship between 2D:4D and HGS of both hands in men and women.Methods: Scanned images of both hands of young volunteers were analysed and the 2D:4D ratio calculated. HGS was measured and results correlated with 2D:4D.Results: 2D:4D ratio of men was significantly less than of women for the right (p<0.001) and the left hand (p<0.001). HGS of men was significantly greater than that of women for the right (p<0.0001) and for the left hand (p<0.0001). 2D:4D ratio in men showed a weak but significant positive correlation with HGS of right(p<0.05) and left hand(p<0.05). A weak but significant positive correlation was also seen for the left hand in females. However, 2D:4D ratios did not show any significant correlation with HGS for the right hand in women.Conclusions: We conclude that 2D:4D ratio is a measure of Hand Grip Strength in men, but is not a robust measure of HGS in women.

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