To determine if there is any benefit to static stretching after performing a dynamic warm-up in the prevention of injury in high school soccer athletes.
Prospective cluster randomized nonblinded study.
12 high schools with varsity and junior varsity boys' soccer teams (24 soccer teams) across the state of Michigan.
Four hundred ninety-nine student-athletes were enrolled, and 465 completed the study. One high school dropped out of the study in the first week, leaving a total of 22 teams.
Dynamic stretching protocol vs dynamic + static (D+S) stretching protocol.
MAIN OUTCOME MEASURES:
Lower-extremity, core, or lower-back injuries per team.
Twelve teams performed the dynamic stretching protocol and 10 teams performed the D+S stretching protocol. There were 17 injuries (1.42 ± 1.49 injuries/ team) among the teams that performed the dynamic stretching protocol and 20 injuries (2.0 ± 1.24 injuries/ team) among the teams that performed the D+S protocol. There was no statistically significant difference in injuries between the 2 groups (P = .33).
There is no difference between dynamic stretching and D+S stretching in the prevention of lower-extremity, core, and back injuries in high school male soccer athletes. Static stretching does not provide any added benefit to dynamic stretching in the prevention of injury in this population before exercise.
Hamstring injuries are the most common muscle injuries in soccer, and they have a high rate of recurrence. Eccentric hamstrings strength is recognized as an important modifiable risk factor. This led to the development of prevention exercises such as the nordic hamstring exercise (NHE). The effectiveness of the NHE on hamstring injury prevention has never been investigated in amateur soccer.
To investigate the preventive effect of the NHE on the incidence and severity of hamstring injuries in male amateur soccer players.
Randomized controlled trial; Level of evidence, 1.
Male amateur soccer players (age, mean ± SD, 24.5 ± 3.8 years) from 40 teams were randomly allocated to an intervention (n = 20 teams, 292 players) or control group (n = 20 teams, 287 players). The intervention group was instructed to perform 25 sessions of NHE in a 13-week period. Both the intervention and control groups performed regular soccer training and were followed for hamstring injury incidence and severity during the 2013 calendar year. At baseline, personal characteristics (eg, age, injury history, field position) were gathered from all participants via a questionnaire. Primary outcome was injury incidence. Secondary outcomes were injury severity and compliance with the intervention protocol.
A total of 38 hamstring injuries were recorded, affecting 36 of 579 players (6.2%). The overall injury incidence rate was 0.7 (95% CI, 0.6-0.8) per 1000 player hours, 0.33 (95% CI, 0.25-0.46) in training, and 1.2 (95% CI, 0.82-1.94) in matches. Injury incidence rates were significantly different between the intervention (0.25; 95% CI, 0.19-0.35) and control groups (0.8; 95% CI, 0.61-1.15), ?2(1, n = 579) = 7.865; P = .005. The risk for hamstring injuries was reduced in the intervention group compared with the control group (odds ratio, 0.282; 95% CI, 0.110-0.721) and was statistically significant (P = .005). No statistically significant differences were identified between the intervention and control groups regarding injury severity. Compliance with the intervention protocol was 91%.
Incorporating the NHE protocol in regular amateur training significantly reduces hamstring injury incidence, but it does not reduce hamstring injury severity. Compliance with the intervention was excellent.
Athletes with non-contact anterior cruciate ligament tears have common features in the sagittal plane; namely, the body's center of mass (COM) is located posterior to the base of support, the trunk and knee joints are extended, and the hip angle is flexed. However, the relationships among these variables have not been assessed in field-based movements. This study sought to determine relationships between distances from the COM to the base of support and the trunk, hip, and knee positions in women while playing soccer. Sixty events (29 single-leg landing and 31 single-leg stopping events) were analyzed using two-dimensional video analysis. The relationships among the measurement variables were determined using the Pearson's product-moment correlation coefficient, and stepwise multiple linear regression models were used to explore the relationships between the COM position and the kinematic variables. The distance from the COM to the base of support displayed a moderate negative relationship with the trunk angle (r = -0.623, p < .0001, r(2) = 0.388) and a strong positive relationship with the limb angle (r = 0.869, p < .0001, r(2) = 0.755). The limb, knee, and trunk angles were selected in the best regression model (adjusted r(2) = 0.953, p < .0001, f(2) = 20.277). These findings suggest that an increased trunk angle and a decreased limb angle at initial contact are associated with a safer COM position. Neuromuscular training may be useful for controlling the trunk and lower limb positions during dynamic activities.
Reported injuries in male youth soccer occur mainly in the lower extremities with a higher occurrence of noncontact incidents and a predominance of ligament sprains at the ankle and knee. More specifically, the medial collateral ligament (MCL) and anterior talofibular ligament are the most commonly reported injuries. For young athletes, the risk of sports-related injury is heightened at various stages of growth and maturation. Specifically, with an increase in a child's age, there is greater exposure to training and competition, which involves high levels of repetitive loading that can increase injury ris. Furthermore, a linear increase in injury rates has been reported from 9 to 15 years of age in male players, with a marked increase around the age of 13 years. Chronologically, these ages coincide with rapid changes in stature and mass as a result of maturational processes. During adolescence, males will experience peak height velocity (PHV) at around age 14, which refers to the time at maximal rate of growth during the adolescent growth spurt. Recent research shows that elite male youth soccer players experience more traumatic injuries in the year of PHV, which underlines the greater occurrence of sports injuries with later stages of maturation.
Recent trends have highlighted a range of injury risk factors and the importance of injury prevention strategies within female soccer players. However, there is a paucity of information on male youth players. Due to the physical demands of soccer, the associated injury risk, and the number of children and adolescents who participate in the sport, there is a clear need for increased research within male soccer players to identify age and sex specific injury risk factors. Specifically, practitioners working with youth male players must be cognizant of a range of modifiable and nonmodifiable risk factors that are specific to pediatric populations, which may increase injury risk. Hence, the focus of this review is to outline a range of considerations pertaining to male youth soccer players, which may contribute to their relative risk of injury.
This study aimed to investigate whether treadmill versus overground soccer match simulations have similar effects on knee joint mechanics during side cutting. Nineteen male recreational soccer players completed a 45-min treadmill and overground match simulation. Heart rate (HR) and rating of perceived exertion (RPE) were recorded every 5 min. Prior to exercise (time 0 min), at “half-time” (time 45 min) and 15 min post-exercise (time 60 min), participants performed five trials of 45° side-cutting manoeuvres. Knee abduction moments and knee extension angles were analysed using two-way repeated measures analysis of variance (? = 0.05). Physiological responses were significantly greater during the overground (HR 160 ± 7 beats ? min?1; RPE 15 ± 2) than the treadmill simulation (HR 142 ± 5 beats ? min?1; RPE 12 ± 2). Knee extension angles significantly increased over time and were more extended at time 60 min compared with time 0 min and time 45 min. No significant differences in knee abduction moments were observed. Although knee abduction moments were not altered over time during both simulations, passive rest during half-time induced changes in knee angles that may have implications for anterior cruciate ligament injury risk.
Young male soccer players have been identified as a target group for injury prevention, but studies addressing trends and determinants of injuries within this group are scarce. The goal of this study was to analyze age-specific trends in hospital-treated upper extremity fractures (UEF) among boys playing soccer in the Netherlands and to explore associated soccer-related factors. Data were obtained from a national database for the period 1998–2009. Rates were expressed as the annual number of UEF per 1000 soccer players. Poisson's regression was used to explore the association of UEF with the number of artificial turf fields and the number of injuries by physical contact. UEF rates increased significantly by 19.4% in boys 5–10?years, 73.2% in boys 11–14?years, and 38.8% in boys 15–18?years old. The number of injuries by physical contact showed a significant univariate association with UEF in boys 15–18?years old. The number of artificial turf fields showed a significant univariate association with UEF in all age groups, and remained significant for boys aged 15–18?years in a multivariate model. This study showed an increase of UEF rates in boys playing soccer, and an independent association between artificial turf fields and UEF in the oldest boys.
Identifying neuromuscular screening factors for anterior cruciate ligament (ACL) injury is a critical step toward large-scale deployment of effective ACL injury-prevention programs. The Landing Error Scoring System (LESS) is a valid and reliable clinical assessment of jump-landing biomechanics.
To investigate the ability of the LESS to identify individuals at risk for ACL injury in an elite-youth soccer population.
Field-based functional movement screening performed at soccer practice facilities.
Patients or Other Participants:
A total of 829 elite-youth soccer athletes (348 boys, 481 girls; age ¼ 13.9 6 1.8 years, age range ¼ 11 to 18 years), of whom 25% (n ¼ 207) were less than 13 years of age.
Baseline preseason testing for all participants consisted of a jump-landing task (3 trials). Participants were followed prospectively throughout their soccer seasons for diagnosis of ACL injuries (1217 athlete-seasons of follow-up).
Main Outcome Measure(s):
Landings were scored for ‘‘errors’’ in technique using the LESS. We used receiver operator characteristic curves to determine a cutpoint on the LESS. Sensitivity and specificity of the LESS in predicting ACL injury were assessed.
Seven participants sustained ACL injuries during the follow-up period; the mechanism of injury was noncontact or indirect contact for all injuries. Uninjured participants had lower LESS scores (4.43 6 1.71) than injured participants (6.24 6 1.75; t1215 ¼ 2.784, P ¼ .005). The receiver operator characteristic curve analyses suggested that 5 was the optimal cutpoint for the LESS, generating a sensitivity of 86% and a specificity of 64%.
Despite sample-size limitations, the LESS showed potential as a screening tool to determine ACL injury risk in elite-youth soccer athletes.
Elite-level professional soccer players are suggested to have increased physical, technical, tactical, and psychological capabilities when compared with their subelite counterparts. Ensuring these players remain at the elite level generally involves training many different bodily systems to a high intensity or level within a short duration. This study aimed to examine whether an increase in training volume at high-intensity levels was related to injury incidence, or increased the odds of sustaining an injury. Training intensity was monitored through time spent in high-intensity (T-HI) and very high-intensity (T-VHI) zones of 85-<90% and ?90% of maximal heart rate (HRmax), and all injuries were recorded over 2 consecutive seasons. Twenty-three, elite professional male soccer players (mean ± SD age, 25.6 ± 4.6 years; stature, 181.8 ± 6.8 cm; and body mass, 79.3 ± 8.1 kg) were studied throughout the 2-years span of the investigation. The results showed a mean total injury incidence of 18.8 (95% confidence interval [CI], 14.7-22.9) injuries per 1,000 hours of exposure. Significant correlations were found between training volume at T-HI and injury incidence (r = 0.57, p = 0.005). Further analysis revealed how players achieving more time in the T-VHI zone during training increased the odds of sustaining a match injury (odds ratio = 1.87; 95% CI, 1.12-3.12, p = 0.02) but did not increase the odds of sustaining a training injury. Reducing the number of competitive match injuries among elite-level professional players may be possible if greater focus is placed on the training intensity and volume over a period of time ensuring the potential reduction of fatigue or overuse injuries. In addition, it is important to understand the optimal training load at which adaptation occurs without raising the risk of injury.