Groin Injuries in Soccer: Investigating the Effect of Age on Adductor Muscle Forces

Effectiveness of a Preventative Program for Groin Pain Syndrome in Elite Youth Soccer Players: A Prospective, Randomized, Controlled, Single-Blind Study

Groin pain syndrome (GPS) is a prevalent issue in soccer. This study assessed the effectiveness of a new preventive protocol on GPS for youth soccer players. The protocol included targeted stretching and strengthening exercises for the adductor and core muscles from preseason to midseason. A questionnaire and two pain provocation tests were used for the evaluation. Mild GPS required positive results in at least two evaluations, while severe GPS was associated with pain incompatible with engagement in any activity confirmed by diagnostic ultrasound. Forty-two elite male athletes (aged 16.9 ± 0.7 years) participated in the study, with half of them assigned to the usual training (control group) and the remaining athletes undergoing the preventive protocol (treatment group) for 24 weeks. GPS rates were 14.3% (three diagnoses: two mild, one severe) in the treatment group and 28.6% (six diagnoses: three mild, three severe) in the control group. Toward the end of the season, three players, one from the treatment group and two from the control group had to stop playing due to severe GPS problems. In addition, one player in the control group stopped midseason. Even though the reduction in the risk of developing GPS was not significant (relative risk of 0.50 ([95%CI 0.14 to 1.74], p = 0.2759), the halved incidence of severe GPS and the increased muscle strength related to the treatment (p = 0.0277) are encouraging data for future studies.

Current Clinical Concepts: Exercise and Load Management of Adductor Strains, Adductor Ruptures, and Long-Standing Adductor-Related Groin Pain

Adductor-related groin pain is a common problem in sports. Evidence-based management of athletes with adductor strains, adductor ruptures, and long-standing adductor-related groin pain can be approached in a simple yet effective and individualized manner. In most cases, managing adductor-related pain in athletes should be based on specific exercises and loading strategies. In this article, I provide an overview of the different types of adductor injuries, from acute to overuse, including their underlying pathology, functional anatomy, diagnosis, prognosis, mechanisms, and risk factors. This information leads to optimal assessment and management of acute to long-standing adductor-related problems and includes primary, secondary, and tertiary prevention strategies that focus on exercise and load-based strategies. In addition, information on different options and contexts for exercise selection and execution for athletes, athletic trainers, and sports physical therapists in adductor injury rehabilitation is provided.

The associations of early specialization, sports volume, and maturity status with musculoskeletal injury in elite youth football players

Background: Youth football in schools has experienced rapid growth in China. Despite the increase of players engaging in more frequent, intensive, and organized sports training at their early ages, the controversy over early specialization (ES) still exists. This study aims to: a) investigate the training situation of players in the Chinese School Football Programme and b) examine the associations of early specialization, sports volume, and maturity status with musculoskeletal injury. Methods: A cross-sectional survey was used. Players who participated in the National School Football Winter Camp were invited to fill out a questionnaire that included the data of maturity, ES, sports volume, and injury history (n = 88 boys and n = 90 girls). Results: The results have shown that 80.3% of the athletes were classified as ES, while 19.7% of them were classified as non-ES. Almost all athletes (96%) participated in a sport for more than 8 months in a year. Most athletes (75.8%) spent more than twice of the time on organized sports than leisure activities. 30.3% of the athletes trained on average more hours per week than the number of their ages. Binomial logistic regression models reflected the significant differences in the odds ratios (OR) of reporting a history of injury among athletes with different levels of specialization (p = 0.024) and the OR of reporting a history of leg injury among players with different weekly sports volumes (p = 0.038). Significant differences were also shown in the OR of players reporting foot injuries between players with different maturity states (p = 0.046), and the Chi-squared test showed significant differences in the OR of reporting acute injuries between players with different levels of specialization (p = 0.048) and weekly activity (p = 0.022). No significant differences were found between the remaining variables. Conclusion: Most school football elite players follow the ES pathway even though ES increases the risk of injury, especially acute injury. Pre-pubertal and early pubertal players have a higher incidence of foot injuries. Players who train more hours per week than their ages have more leg injuries and acute injuries. Therefore, priority protection and intervention should be carried out for populations with a high risk of injury.

Are sprint accelerations related to groin injuries? A biomechanical analysis of adolescent soccer players

Groin injuries have one of the highest incidences in soccer and can be career threatening, especially for adolescents, due to their high recurrence rate. Quick accelerations have been connected to groin injuries along with kicking and change of directions. Purpose of this study was to examine the hip joint kinematics, kinetics and the muscle forces of adductor longus and gracilis during first ground contact of a linear sprint acceleration performed by adolescent soccer players. Twenty-two male participants were investigated with 3D motion capture and two force plates. Inverse dynamics were used to calculate the kinematics, kinetics and muscle forces. The kinematics show a constant extension during the stance phase and a quick transition from an abduction to an adduction movement at 90% stance, which coincides with the highest forces in adductor longus and gracilis. This indicates a high load on the adductor muscles due to eccentric contractions combined with high muscle forces in the adductors. Compared to previously investigated inside passing and change of direction movements, adductor muscle forces and angular velocities are higher in this study. Therefore, it is suggested that sprint accelerations are likely to be connected to the development of groin injuries in adolescent soccer players.

Rapid Spike in Hip Adduction Strength in Early Adolescent Footballers: A Study of 125 Elite Male Players From Youth to Senior

PURPOSE

To investigate the differences in hip adductor and abductor muscle strength in elite male footballers from youth to senior level.

METHODS

We tested 125 players from the under-13-years (U'13) to senior squads of a Danish male professional football club in this cross-sectional design study. Hip adductor and abductor force (in newtons), torque (in newton meters), normalized torque (in newton meters per body mass), and adduction-to-abduction ratio were measured using handheld dynamometry.

RESULTS

Between U'13 and senior level, adductor force increased by 104%, torque by 127%, and normalized torque by 21%. Abductor force increased by 78%, torque by 126%, and normalized torque by 17%. For incremental differences between age groups, significant increases were observed between the ages of U'13 to U'14 (18%-39%) and U'14 to U'15 (19%-33%) for all strength measures (P ≤ .021). No incremental difference was observed for adductor-to-abductor ratio.

CONCLUSIONS

The large increases in hip adductor and abductor strength occurring between the ages of U'13 and U'15 offer insight into the strength capabilities and stress demands in these players, which may relate to injury vulnerability, and facilitate clinicians in selecting best-suited exercise interventions.

Part 2 of the 11+ as an effective home-based exercise programme in elite academy football (soccer) players: a one-club matched-paired randomised controlled trial

Background:Although the 11+ is known to reduce injuries and improve performance in adolescent footballers, its duration presents a notable barrier to implementation. Hence, this study investigated injury and performance outcomes when 65 elite male academy footballers either performed Part 2 3x/week at training (TG) or at home (HG).Methods:Time to stabilisation (TTS), eccentric hamstring strength (EH-S) and countermovement jump height (CMJ-H) were collected 4 times during the 2019 football season. Linear mixed models were used to evaluate main and interaction effects of group and time. Bonferroni post-hoc tests were used to account for multiple comparisons. Differences in time loss and medical attention injuries were determined using a two-tailed Z test for a comparison of rates.Results:Relative to baseline, EH-S (HG 4.3 kg, 95% CI 3 to 5.7, p < 0.001; TG 5.5 kg, 95% CI 4.3 to 6.6, p < 0.001) and CMJ-H (HG 3.5 cm, 95% CI 2.2 to 4.7, p < 0.001; TG 3.2 cm, 95% CI 2.2 to 4.3, p < 0.001) increased, with no difference between groups observed at the end of the season. All injury outcomes were similar.Conclusion: Rescheduling Part 2 did not affect performance or increased injury risks in academy footballers.

Factors Associated with Hip and Groin Pain in Elite Youth Football Players: A Cohort Study

BACKGROUND

Despite hip and groin pain being commonly reported in elite youth football players, little evidence on risk factors exists. Risk factors in adult football players include reduced hip adductor strength and hip adductor/abductor strength ratios, and lower Copenhagen Hip and Groin Outcome Score (HAGOS) subscale scores. It is unknown if these factors are also predictive of pain development in youth football players.

OBJECTIVE

To identify whether preseason hip adductor and abductor strength and HAGOS subscale scores of male and female elite youth football players are associated with in-season or historical (lifetime) hip and groin pain.

METHODS

Preseason hip adductor and abductor strength testing and the HAGOS were undertaken by 105 elite male (n = 58) and female (n = 47) football players aged 11-15 years. Medical staff documented both players' self-reported historical and in-season hip and groin pain. Univariate and multivariate logistic regression models were undertaken with main outcome measures in-season hip and groin pain and historical hip and groin pain and independent variables of hip muscle strength, hip muscle torque and HAGOS subscale scores.

RESULTS

Twenty-three players (21.9%) self-reported in-season hip and groin pain, while 19 players (18.1%) self-reported historical hip and groin pain. Pre-season hip adductor and abductor variables and HAGOS subscale scores failed to predict in-season hip and groin pain. However, a higher body mass index (odds ratio [OR] = 1.32; 95% CI 1.01, 1.73, p = .043) and being male (OR 5.71; 95% CI 1.65, 19.7) were associated with having in-season hip and groin pain (R2 = 0.211). There was also an association between historical hip and groin pain (R2 = 0.579) and both HAGOS subscale Quality of Life (odds ratio [OR] = 0.84; 95% CI 0.77, 0.91, p < .001) and mean abductor torque (OR = 11.85; 95% CI 1.52, 91.97; p = .018).

CONCLUSION

Pre-season hip adductor and abductor strength and HAGOS subscale scores did not predict subsequent in-season hip and groin pain in elite youth football players. However, pre-season higher hip abductor strength and lower HAGOS scores were retrospectively associated with historical hip and groin pain.

Association of Skeletal Maturity and Injury Risk in Elite Youth Soccer Players: A 4-Season Prospective Study With Survival Analysis

BACKGROUND

The association between injury risk and skeletal maturity in youth soccer has received little attention.

PURPOSE

To prospectively investigate injury patterns and incidence in relation to skeletal maturity in elite youth academy soccer players and to determine the injury risks associated with the skeletal maturity status, both overall and to the lower limb apophysis.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All injuries that required medical attention and led to time loss were recorded prospectively during 4 consecutive seasons in 283 unique soccer players from U-13 (12 years of age) to U-19 (18 years). The skeletal age (SA) was assessed in 454 player-seasons using the Fels method, and skeletal maturity status (SA minus chronological age) was classified as follows: late, SA >1 year behind chronological age; normal, SA ±1 year of chronological age; early, SA >1 year ahead of chronological age; and mature, SA = 18 years. An adjusted Cox regression model was used to analyze the injury risk.

RESULTS

A total of 1565 injuries were recorded; 60% were time-loss injuries, resulting in 17,772 days lost. Adjusted injury-free survival analysis showed a significantly greater hazard ratio (HR) for different status of skeletal maturity: early vs normal (HR = 1.26 [95% CI, 1.11-1.42]; P < .001) and early vs mature (HR = 1.35 [95% CI, 1.17-1.56]; P < .001). Players who were skeletally mature at the wrist had a substantially decreased risk of lower extremity apophyseal injuries (by 45%-61%) compared with late (P < .05), normal (P < .05), and early (P < .001) maturers.

CONCLUSION

Musculoskeletal injury patterns and injury risks varied depending on the players' skeletal maturity status. Early maturers had the greatest overall adjusted injury risk. Players who were already skeletally mature at the wrist had the lowest risk of lower extremity apophyseal injuries but were still vulnerable for hip and pelvis apophyseal injuries.

Short and long lever adductor squeeze strength values in 100 elite youth soccer players: Does age and previous groin pain matter?

OBJECTIVE

To examine adductor squeeze strength in elite youth soccer players by investigating the relationship of age and previous one-year groin pain on adductor squeeze force outputs, and to provide reference values for youth players.

DESIGN

Cross-sectional study.

PARTICIPANTS

Elite youth soccer players (n = 100; age 14.5 ± 1.9 years; height 168.0 ± 10.7 cm; mass 60.7 ± 13.0 kg) participated.

MAIN OUTCOME MEASURES

Adductor squeeze tests were captured in short and long lever positions, and groin pain assessed via subjective retrospective questionnaire. Multiple linear regressions were computed to compare the effects of age and previous one-year groin pain on adductor squeeze strength.

RESULTS

Raw adductor squeeze force values (N) had a moderate positive relationship with age (short r = 0.517, p < 0.001; long r = 0.457, p < 0.001), but not when force is normalized to body mass (N/kg; short r = 0.014, p = 0.444; long r = -0.173, p = 0.043). Previous groin pain did not have an effect on short or long lever squeeze strength. Reference values for long lever adductor squeeze strength (3.59 ± 0.77 Nm/kg) are provided.

CONCLUSION

Age and previous groin pain do not have an effect on adductor squeeze strength values in elite youth soccer players, so comparing values to the present adolescent cohort can be quickly interpreted without adjustment for age or previous injury.

Groin injury risk of pubertal soccer players increases during peak height velocity due to changes in movement techniques

Adolescent athletes experience an increase in injury incidence when they undergo peak height velocity (PHV). To find the reason behind this increase, the present study investigated if PHV influences hip joint kinematics, kinetics and adductor muscle forces in two groups of adolescent soccer players performing 90^°-cutting manoeuvres and inside passing. One group was estimated to be more than half a year before PHV (PRE, N = 12). The second group was estimated to be less than half a year before or after PHV (MID, N = 10). Maximum static gripping and adductor forces were measured. Motion capturing and inverse dynamics were used to calculate kinematics and kinetics. The MID group was significantly taller and heavier compared to PRE while the force measurements showed no differences. Statistics showed a higher hip abduction moment for MID during the cutting manoeuvre. Results from the anthropometrics and force measurements suggest that the moments of inertia of the participants' extremities increase faster than the muscles can adapt. A higher abduction moment of MID likely increases the load on the adductor muscles through a change of technique. Combining both findings, it is likely that the risk of suffering a groin injury is increased in the MID group.