Isokinetic knee muscle strength of soccer players according to their position

BACKGROUND: The isokinetic hamstrings to quadriceps (H:Q) dynamic control ratio (DCR) is frequently used to assess muscle imbalances and to screen for potential risks of knee injuries in sports. OBJECTIVE: To investigate the correlation between knee conventional ratio (CR) and DCR in elite soccer players and check for a possible relationship. A positive correlation would indicate that the CR could predict DCR. METHODS: One hundred and thirteen Brazilian elite soccer players (25.2 ± 5.3 yrs) performed maximal dominant and nondominant knee concentric (CON) and eccentric (ECC) strength tests at 60 • /s on an isokinetic dynamometer in order to calculate CR and DCR. RESULTS: A significant positive correlation between ratios was found for the dominant and non-dominant knees (r = 0.54 and 0.62; p < 0.001 which translated into low R 2 values of 0.29 and 0.39, respectively. CONCLUSION: This suggests that the CR may not replace the DCR and is thus of a limited clinical value in assessing knee muscles imbalance. On the other hand, the paper presents for the first time a robust reference frame for the isokinetic strength and related ratios of the two major knee muscles in soccer players.

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“…This is in accordance with the well established physiological expectations [42,43]. This also demonstrates the importance of the DCR assessment.…”

Section: Discussionsupporting

confidence: 92%

The association between conventional and dynamic control knee strength ratios in elite soccer players

Ruas

Pinto

Brown

et al. 2015

IES

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“…These results are in agreement with the study of Rahnama et al (2005) that reported no significant differences between the two legs in knee extensors at three different velocities (60, 120, 300°/s) among elite soccer players. Tourny-Chollet et al (2000) investigated 21 (22.0±2.95 years) amateur female soccer players. Their results showed a significant difference at medium speed between hamstring muscles in the dominant and non-dominant legs.…”

Section: Discussionmentioning

confidence: 99%

“…Their results showed a significant difference at medium speed between hamstring muscles in the dominant and non-dominant legs. Tourny-Chollet et al (2000) concluded that the knee flexor of the dominant leg tended to be stronger than that of the non-dominant leg. The finding is, however, in contrast with that of the present study.…”

Section: Discussionmentioning

confidence: 99%

“…Researchers across many sports regard the value of 0.6 as normative for the conventional strength ratio (CSR) at 60°/s which increases up to 0.8 with increased movement velocity (Hewett et al, 2008; Grygorowicz et al, 2010; Hadzic et al, 2010). It has been suggested that the CSR of less than 0.6 would indicate a strength imbalance between the quadriceps and hamstrings which could predispose one to injury (Tourny-Chollet et al, 2000). The results of such testing which used the CSR and dynamic control ratio (DCR= eccentric PT of hamstrings/concentric PT of quadriceps) to describe muscle balance can be used in knee injury prevention (Grygorowicz et al, 2010; Fousekis et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

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Bilateral and Unilateral Asymmetries of Isokinetic Strength and Flexibility in Male Young Professional Soccer Players

Daneshjoo

Rahnama

Mokhtar

et al. 2013

Journal of Human Kinetics

151

148

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This study investigated bilateral and unilateral asymmetries of strength and flexibility in male young professional soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) participated in this study. A Biodex Isokinetic Dynamometer was used to assess the hamstring and quadriceps strength at selected speeds of 60°/s, 180°/s and 300°/s. Hip joint flexibility was measured using a goniometer. No difference was observed in conventional strength ratio, dynamic control ratio and fast/slow speed ratio between the dominant and non-dominant legs (p>0.05). All but one of the players (97.2%) had musculoskeletal abnormality (bilateral imbalance > 10%) in one or more specific muscle groups. The dominant leg had greater hip joint flexibility compared with the non-dominant leg (108.8 ± 10.7° versus 104.6 ± 9.8°, respectively). The findings support the hypothesis that physical performance and movement pattern experienced during soccer playing may negatively change the balance of strength in both legs (bilateral strength balance), but not on the same leg of the young male professional soccer players. The results can be helpful for trainers and coaches to decide whether the players need to improve their balance and strength which in turn may prevent injury. It is suggested that in professional soccer training, quadriceps and hamstrings muscle strength, as well as hip joint flexibility should not be overlooked.

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“…It may therefore be speculated that years of training exposure has an eff ect upon this variable [15] , an eff ect which has also been termed " trainability " [20] . Further research is required to investigate this eff ect, especially since dom: ndom diff erences in PT have rarely been found in adult footballers [22,29,31] .…”

Section: Absolute Peak Torquementioning

confidence: 99%

Isokinetic Thigh Muscle Ratios in Youth Football: Effect of Age and Dominance

et al. 2009

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This study aimed to analyse the effect of age on muscle peak torque (PT), and Hamstring (H): Quadricep (Q) ratio in elite youth footballers. To date, no study has considered age-group playing level and pubertal development in this population. One hundred and fifty-seven elite youth footballers in the age groups U12 to U18 volunteered to participate in this study, 133 of these were further grouped for pubertal development. Prior to testing subjects completed separate familiarisation, a three minute cycle ergometer warm up (resistance 50-60W), and two sub-maximal repetitions. Concentric and eccentric isokinetic PT measures for reps 2-4 of H and Q muscle action were taken at 60 degrees s (-1). From this, conventional and functional H: Q ratio was calculated along with dominant: non dominant ratio for the concentric Q and H, and eccentric H conditions. Significant main effects were observed for the age/pubertal development group and PT in all muscles and conditions (P<0.05). Of particular interest was a significant main effect for age and Functional H: Q (P<0.05), which suggested a move away from equality at U18. Our study provides normative data for coaches, trainers and clinicians working with youth footballers and may also have connotations for injury prevention and performance.

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Isokinetic knee muscle strength of soccer players according to their position

Cited by 51 publications

References 12 publications

The association between conventional and dynamic control knee strength ratios in elite soccer players

The association between conventional and dynamic control knee strength ratios in elite soccer players

Bilateral and Unilateral Asymmetries of Isokinetic Strength and Flexibility in Male Young Professional Soccer Players

Isokinetic Thigh Muscle Ratios in Youth Football: Effect of Age and Dominance

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