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

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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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  • Alentorn-Geli E Myer GD Silvers HJ Samitier G Romero D Lázaro-Haro C Cugat R. Prevention of noncontact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors. Knee Surg Sports Traumatol Arthrosc 2009; 17(7): 705-729

  • Amiri-Khorasani M Abu Osman NA Yusof A. Acute effect of static and dynamic stretching on hip dynamic range of motion (DROM) during instep kicking in professional soccer players. J Strength Cond Res 2011; 25(6): 1647-52

  • Arnason A Sigurdsson SB Gudmundsson A Holme I Engebretsen L Bahr R. Risk factors for injuries in football. Am J Sports Med 2004; 32: 5S-16S

  • Bottinelli R Canepari M Pellegrino MA Reggiani C. Force-velocity properties of human skeletal muscle fibres: myosin heavy chain isoform and temperature dependence. J Physiol 1996; 495(2): 573-586

  • Bradley PS Portas MD. The relationship between preseason range of motion and muscle strain injury in elite soccer players. J Strength Cond Res 2007; 21(4): 1155-59

  • Brito J Fernandes L Seabra A Soares JM Krustrup P Rebelo A. Isokinetic strength effects of FIFA’s “The 11+” injury prevention training programme. Isokinet Exerc Sci 2010; 18: 211-215

  • Chin MK So RCH Yuan YWY Li RCT Wong ASK. Cardiorespiratory fitness and isokinetic muscle strength of elite Asian junior soccer players. J Sport Med Phys Fit 1994; 34: 250-257

  • Dauty M Potiron-Josse M Rochcongar P. Identification of previous hamstring muscle injury by isokinetic concentric and eccentric torque measurement in elite soccer players. Isokinet Exerc Sci 2003; 11: 139-144

  • Dugan SA. Sports-related knee injuries in female athletes: what gives? Am J Phys Med Rehabil 2005; 84: 122-130

  • Ekstrand J Gillquist J. Frequency of muscle tightness and injuries in soccer players. Am J Sports Med 1982; 10: 75-78

  • Fousekis K Tsepis E Poulmedis P Athanasopoulos S Vagenas G. Intrinsic risk factors of non-contact quadriceps and hamstring strains in soccer: a prospective study of 100 professional players. Br JSports Med 2011; 45(9): 709-14

  • Fousekis K Τsepis E Vagenas G. Lower limb strength in professional soccer players: profile asymmetry and training age. Sports Sci Med 2010; 9: 364-373

  • FIFA website. FIFA big count 2006: 270 million people active in football. 2006. 2006. Available at: statspackage_ 7024 .pdf; accessed on 8.11.2012

  • Gabbe BJ Finch C Bennell K Wajswelner H. Risk factors for hamstring injuries in community level Australian football. Br J Sports Med 2005; 39(2): 106-110

  • Gil SM Gil J Ruiz F Irazusta A Irazusta J. Anthropometrical characteristics and somatotype of young soccer players and their comparison with the general population. Biol Sport 2010; 27: 17-24

  • Grygorowicz M Kubacki J Pilis W Gieremek K Rzepka R. Selected isokinetic test in knee injury prevention. Biol Sport 2010; 27 (1): 47-51

  • Hadzic V Sattler T Markovic G Veselko M Dervisevic E. The isokinetic strength profile of quadriceps and hamstrings in elite volleyball players. Isokinet Exerc Sci 2010; 18: 31-37

  • Hardt J Benjanuvatra N Blanksby B. Do footedness and strength asymmetry relate to the dominant stance in swimming track start? J Sports Sci 2009; 27(11): 1221-1227

  • Hewett TE Myer GD Zazulak BT. Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity. J Sci Med Sport 2008; 11: 452-459

  • Holcomb WR Rubley MD Lee HJ Guadagnoli MA. Effect of hamstring-emphasized resistance training on hamstring: quadriceps strength ratios. J Strength Cond Res 2007; 21(1): 41-47

  • Hrysomallis C. Hip adductors' strength flexibility and injury risk. J Strength Cond Res 2009; 23(5) 1514-1517

  • Iga J George K Lees A Reilly T. Cross-sectional investigation of indices of isokinetic leg strength in youth soccer players and untrained individuals. Scand J Med Sci Sports 2009; 19: 714-719

  • Kiani A Hellquist E Ahlqvist K Gedeborg R Michaëlsson K Byberg L. Prevention of soccer-related knee injuries in teenaged girls. Arch Intern Med 2010; 170(1): 43-49

  • Kim D Hong J. Hamstring to quadriceps strength ratio and noncontact leg injuries: A prospective study during one season. Isokinet Exerc Sci 2011; 19(1): 1-6

  • Knapik JJ Bauman CL Jones BH Harris JMcA Vaughan L. Preseason strength and flexibility imbalances associated with athletic injuries in female collegiate athletes. Am J Sports Med 1991; 19: 76- 81

  • Kofotolis ND Kellis E. Cross-training effects of a proprioceptive neuromuscular facilitation exercise program on knee musculature. Phys Ther Sport 2007; 8: 109-116

  • Lehance C Binet J Bury T Croisier JL. Muscular strength functional performances and injury risk in professional and junior elite soccer players. Scand J Med Sci Sports 2009; 19: 243-251

  • Loes M Dahlstedt LJ Thomee R. A 7-year study on risks and costs of knee injuries in male and female youth participants in 12 sports. Scand J Med Sci Sports 2000; 10: 90-97

  • Malý T Zahálka F Malá L. Isokinetic strength ipsilateral and bilateral ratio of peak muscle torque in knee flexors and extensors in elite young soccer players. Acta Kinesiologica 2010; 4(2): 17-23

  • Manning C Hudson Z. Comparison of hip joint range of motion in professional youth and senior team footballers with age-matched controls: An indication of early degenerative change? Phys Ther Sport 2009; 10(1): 25-29

  • Masuda K Kikuhara N Demura S Katsuta S Yamanaka K. Relationship between muscle strength in various isokinetic movements and kick performance among soccer players. J Sport Med Phys Fit 2005; 45: 44-52

  • Norkin C White D. Measurement of Joint Motion: A Guide to Goniometry. F A Davis Company Philadelphia USA. 2003: 181-241

  • Ozcaldiran B. Knee flexibility and knee muscles isokinetic strength in swimmers and soccer players. IsokinetExerc Sci 2008; 16: 55-59

  • Oshita K Yano S. Asymmetry of force fluctuation during low intensity isometric contraction in leg muscle. Int J Exerc Sci 2010; 3(2): 68-77

  • Rahnama N Lees A Bambaecichi E. A comparison of muscle strength and flexibility between the dominant and non-dominant leg in English soccer players. Ergonomics 2005; 48(11-14): 1568-1575

  • Rahnama N. Prevention of football injuries. Int J Prev Med 2011; 2(1): 38-40

  • Schiltz M Lehance C Maquet D Bury T Crielaard JM Croisier JL. Explosive strength imbalances in professional basketball players. J Athl Train 2009; 44(l): 39-47

  • Tourny-Chollet C Leroy D Eger HL Beuret-Blanquart F. Isokinetic knee muscle strength of soccer players according to their position. Isokinet Exerc Sci 2000; 8: 187-193

  • Verrall GM Slavotinek JP Barnes PG Fon GT and Spriggins AJ. Clinical risk factors for hamstring muscle strain injury: a prospective study with correlation of injury by magnetic resonance imaging. Br JSports Med 2001; 35: 435-439

  • Worrel TW Perrin DH Gansneder BM Gieck JH. Comparison of isokinetic strength and flexibility measures between hamstring injured and non-injured athletes. J Orthop Sports Phys Ther 1991; 13(3): 118-25

  • Zakas A. Bilateral isokinetic peak torque of quadriceps and hamstring muscles in professional soccer players with dominance on one or both two sides. J Sport Med Phys Fit 2006; 46: 28-35

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