Introduction and Purpose
Isokinetic evaluations of thigh muscles in professional soccer players are commonly used for a functional assessment during training, to highlight possible individual hamstring/quadriceps (H/Q) imbalances (1): these differences are often related only to variations in H/Q ratios, especially using the functional H eccentric/Q concentric ratio, an index particularly important for the prevention of muscle and joint injuries (1,2). Almost all studies were performed on professional male athletes, but very few papers were dedicated to the isokinetic assessment of female soccer players (2,3). The purpose of the present study was to detect the isokinetic H/Q ratios in a group of top level female soccer players.
Methods
16 professional female soccer players were selected for this study: 1 goal-keeper, 5 defenders, 5 midfielders and 5 strikers, all belonging to an Italian First Premier League team (Female Soccer Team Brescia; weekly training: 6 sessions and 1 match on Saturdays). Isokinetic tests, performed during the winter holidays in the 2015-2016 competitive season, consisted of Dominant (D) and Not Dominant (N) knee extensors (Q) and flexors (H) muscles evaluations by a Genu 3 isokinetic device (Easytech, Florence, Italy). The test protocol consisted of H and Q concentric exertions (3 repetitions at 90°/sec and 15 repetitions at 240°/sec), followed by 3 eccentric H exertions at 30°/sec. For each athlete, conventional concentric H/Q peak torque ratios (90°/sec and 240°/sec) were calculated for D and N legs, together with functional ratios relating the H eccentric peak torque at 30°/sec and the Q concentric peak torque at 240°/sec. The nature of the deficiency was determined by using statistically selected cut-offs: a 90°/s concentric ratio <0.55, 240°/s concentric ratio <0,65 and a functional ratio <1.
Results
Table 1 shows all anthropometric values and isokinetic H/Q ratios in our study group. All H/Q ratios resulted within the normal range and only 3 athletes showed values lower than at least two cut-off indexes. All statistical comparisons between dominant and not dominant legs were found not statistically significant and, at the same time, no differences were observed on isokinetic ratios among playing roles.
Conclusions
I valori dei rapporti isocinetici delle nostre giocatrici professioniste erano tutti normali e in accordo con i precedenti studi (Bibliografia 2,3). I dati raccolti rafforzano l’ipotesi che parametri isocinetici di questo tipo potrebbero essere molto d’aiuto sia allo staff medico che tecnico per monitorare sia programmi individuali che di squadra. Alti valori di media nei rapporti H/Q, in questo gruppo di calciatrici professioniste, sono probabilmente dovuti alla grande attenzione dedicata al rinforzo dei muscoli H allo scopo di prevenire eventuali lesioni muscolari e articolari durante l’allenamento (Bibliografia 1).
Isokinetic ratios values in our professional female soccer players were all normal and agreed with the other few papers in literature (2,3). These data reinforce the assumption that isokinetic measurements could greatly help the medical and training staff to monitor the individual and team training programs. High mean values in all H/Q ratios, in this group of top level soccer players, are probably related to the great attention dedicated to the strengthening of H muscles, in order to prevent muscle/joint injuries during training (1).
Authors: Giovanni Grazzini degree in sport science, Sebastiano Zuppardo physiotherapist, Gilberto Martelli sport medicine doctor
In collaboration with: Medicine and Surgery Faculty, Dept. of Motor Sciences, University of Florence, Italy ; Pegaso Medical and Rehabilitation Centre, Grosseto, Italy; Female Soccer Team, Brescia, Italy
Published in “Football Medicine Strategies – Return to Play”, edited by Roi G.S. Della Villa S., Calzetti Mariucci, 2016
Submitted at XXV International Conference of Sport Rehabilitation and Traumatology, London, 9th – 11th April 2016
References
Croisier JL, Ganteaume S, Binet J, Genty M, Ferret JM. Strength imbalances and prevention of hamstring injury in professional soccer players: a prospective study. Am J Sports Med 2008; 36: 1469-1475.
Jenkins NDM, Hawkey MJ, Costa PB, Fiddler RE, Thompson BJ, Ryan ED, Smith S, Sobolewski EJ, Conchola EC, Akehi K, Cramer JT. Functional hamstring:quadriceps ratios in elite women’s soccer players. J Sports Sci 2013; 31 (6): 612-617.
Grazzini G, Martelli G. Isokinetic leg flexors/extensors evaluation of male and female soccer players. In: Roi G.S., Della Villa S. (Eds) Abstract Book, 24° International Congress on Sports Rehabilitation and Traumatology, Football medicine strategies for player care. Calzetti e Mariucci, Perugia, 2015, pp 158-159.
