202 Variables associated with knee valgus in male soccer players during a single leg vertical landing task

Childhood anterior cruciate ligament (ACL) injuries—which can pose a major risk to a child’s sporting career—have been on the rise in the last few decades. Dynamic knee valgus (DKV) has been linked to an increased risk of ACL injury. Therefore, the aim of this study was to analyze the acute effects of an ACL injury prevention protocol (ACL-IPP) and a soccer-specific fatigue protocol (SSFP) on DKV in youth male soccer players. The research hypothesis was that DKV would be reduced by the ACL-IPP and increased by the SSFP. Eighteen youth male soccer players were divided according to baseline DKV. Those with moderate or large DKV performed a neuromuscular training protocol based on activation of the abductor and external rotator hip muscles. Those with little or no DKV performed a soccer-specific fatigue protocol. DKV was assessed using the single-leg squat pre- and post-protocols in both legs. The ACL-IPP significantly decreased DKV during single-leg squat (p < 0.01, effect size = 1.39), while the SSFP significantly increased baseline DKV in the dominant leg during single-leg squat (p = 0.012; effect size = 1.74). In conclusion, the ACL-IPP appears to acutely reduce the DKV in youth male soccer players, and the SSFP seems to acutely increase the DKV in those players who showed a light or no DKV in a non-fatigue situation. By using the SSFP, it may be possible to determine which players would benefit from injury prevention programs due to increased DKV during game scenarios, while hip abductor and external rotator neuromuscular training may be beneficial for players who have moderate and severe DKV during single-leg squat under non-fatigued scenarios.

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Modified Functional Movement Screen as a Predictor of Knee Valgus in Male Soccer Players

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000518102.69896.94 ◽

2017 ◽

Vol 49 (5S) ◽

pp. 444

Author(s):

Darby Lindgren ◽

Stuart Borne ◽

Ana B. Freire Ribeiro

Keyword(s):

Soccer Players ◽

Functional Movement Screen ◽

Knee Valgus ◽

Functional Movement ◽

Modified Functional

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Relationship Between Knee Valgus and Ground Reaction Force in Soccer Players Using Soccer Boots Landing on an Official Artificial Turf

The Open Sports Sciences Journal ◽

10.2174/1875399x01710010257 ◽

2017 ◽

Vol 10 (1) ◽

pp. 257-262

Author(s):

João Gustavo Claudino ◽

Bruno Mezêncio ◽

Rafael Soncin ◽

Juliana Pennone ◽

João Pedro Pinho ◽

...

Keyword(s):

Injury Risk ◽

Mechanical Load ◽

Reaction Force ◽

Acl Injury ◽

Soccer Players ◽

Valgus Knee ◽

Knee Valgus ◽

Artificial Turf ◽

Peak Knee ◽

The Relationship

Introduction: There is a high incidence of Anterior Cruciate Ligament (ACL) injuries in soccer and 37% of this happens during landing after a jumping event. The measure of valgus knee moment during landing of a Drop Jump (DJ) has been considered a gold standard test to predict the risk of ACL injury in young athletes. Furthermore, researchers have used 2D frontal angle of the knee trying to make a practical tool to evaluate this injury risk, however, to the best of our knowledge, there is no studies about the relationship between mechanical load and 2D dynamic knee valgus parameters. Purpose: To verify the relationship between kinetics and kinematics ACL injury risk factors: the GRF and the a) peak knee valgus; b) valgus knee displacement in soccer players wearing soccer boots landing on an official synthetic turf. Methods: Twenty Brazilian soccer players, 15-17 years old, with 176.6 ± 6.4 cm of height and 67.4 ± 8.1 kg of body mass participated in this study. Following familiarization, subjects performed the DJ from a height of 40 cm. They landed on two force plates synchronized with Vicon system for kinetic and kinematic analyses, respectively. Results: Only valgus knee displacement (-1.4 ± 7.0 °) and antero-posterior component of GRF (-0.402 ± 0.097 BW) presented a significant relationship (r = 0.353; p = 0.025). Conclusion: There is a significant correlation between knee valgus displacement and GRF antero-posterior component for soccer players in an official artificial turf using soccer boots.

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Landing Kinematics in Elite Male Youth Soccer Players of Different Chronologic Ages and Stages of Maturation

Journal of Athletic Training ◽

10.4085/1062-6050-493-16 ◽

2018 ◽

Vol 53 (4) ◽

pp. 372-378 ◽

Cited By ~ 11

Author(s):

Paul J. Read ◽

Jon L. Oliver ◽

Mark B. A. De Ste Croix ◽

Gregory D. Myer ◽

Rhodri S. Lloyd

Keyword(s):

Age Groups ◽

Soccer Players ◽

Height Velocity ◽

Growth Spurt ◽

Knee Valgus ◽

Peak Height Velocity ◽

Male Youth ◽

Youth Soccer ◽

Left Limb ◽

The Right

Context: Despite the high frequency of knee injuries in athletes, few researchers have studied the effects of chronologic age and stage of maturation on knee-joint kinematics in male youth soccer players. Objective: To use a coach-friendly screening tool to examine knee-valgus scores for players of different ages and at different stages of maturation. Design: Cross-sectional study. Setting: Academy soccer clubs. Patients or Other Participants: A total of 400 elite male youth soccer players aged 10 to 18 years categorized by chronologic age and stage of maturation based on their years from peak height velocity (PHV). Main Outcome Measure(s): Knee valgus was evaluated during the tuck-jump assessment via 2-dimensional analysis. Frontal-plane projection angles were subjectively classified as minor (<10°), moderate (10°–20°), or severe (>20°), and using these classifications, we scored knee valgus in the tuck jump as 0 (no valgus), 1 (minor), 2 (moderate), or 3 (severe). Results: A trend toward higher valgus scores was observed in the younger age groups and the pre-PHV group. The lowest frequency of no valgus occurred in the U18 and post-PHV groups. The highest percentages of severe scores were in the U13 and pre-PHV groups for the right limb. Knee-valgus scores were lower for both lower extremities in the U18 group than in all other age groups (P < .001) except the U16 group. Scores were lower for the post-PHV than the pre-PHV group for the right limb (P < .001) and both pre-PHV and circa-PHV groups for the left limb (P < .001). Noteworthy interlimb asymmetries were evident in the U14, U15, and circa-PHV groups. Conclusions: Reductions in knee valgus with incremental age and during the later stages of maturation indicated that this risk factor was more prevalent in younger players. Interlimb asymmetry may also emerge around the time of the peak growth spurt and early adolescence, potentially increasing the risk of traumatic injury.

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