Article
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

We evaluated a range of physical characteristics related to hamstring injuries, as well as the Nordic Hamstring Exercise compliance rate, and whether this influenced the rate hamstring injury. Subjects comprised 259 male soccer players from seven high schools randomly clustered into two groups, a Nordic Hamstring Exercise group and a control group. Training and match time were logged, as well as details of hamstring injury, and subsequent time lost to hamstring injury recorded over a period of 27 weeks. The Nordic Hamstring Exercise compliance rate, injury rate per 10000 playing hours and time-lost-to-sport-injury rate were calculated. The relative risk and hamstring injury severity were also calculated. The hamstring injury rate was 1.04/10 000 h in the control group and 0.88/10 000 h in the intervention group. The relative risk for hamstring injury was 1.14. The time-lost to injury rate was 1116.3/10 000 h in the control group and 113.7/10 000 h in the intervention group; with relative risk 9.81. The Nordic Hamstring Exercise in high school soccer players significantly reduced hamstring injury severity compared to a control intervention. Our results indicate that the time-lost to injury rate should be taken into account when analyzing the severity of hamstring injury.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Epidemiological surveys have shown that the risk of injury is 1.5 to 2.0 times higher in individuals who regularly participate in various sports [3]. In sports such as basketball, soccer, and rugby, lower extremity injuries are common sports injuries gained during their training and competitions [4,5]. Sports injuries have imposed a significant economic burden on athletes and sports groups [6,7]. ...
... Twenty-three randomized controlled trials, with a total of 18,215 subjects, were included in the literature for analysis. A total of 15,049 lower extremity injury subjects from 15 publications were included in the overall effect test for the overall effect analysis ( Figure 4) [4,5,19,22,27,[39][40][41][42][43][44][45][46][47]. The results suggested an effect size of RR = 0.72 (95% CI: 0.71-0.80; ...
... Twenty-three randomized controlled trials, with a total of 18,215 subjects, were included in the literature for analysis. A total of 15,049 lower extremity injury subjects from 15 publications were included in the overall effect test for the overall effect analysis (Figure 4) [4,5,19,22,27,[39][40][41][42][43][44][45][46][47]. The results suggested an effect size of RR = 0.72 (95% CI: 0.71-0.80; ...
Article
Full-text available
This systematic review and meta-analysis aims to investigate the effects and differences of various hamstring eccentric training protocols for the prevention of lower limb injuries, and we further propose a more refined hamstring eccentric training protocol for the prevention of lower limb injuries. A literature search for the effects of hamstring eccentric training on lower extremity sports injuries was conducted using the PubMed, Web of Science, and EMBASE databases, and the literature was searched covering the period from the date of the database’s creation to 20 August 2022. A meta-analysis of the included literature was performed using R.4.21 for lower extremity injuries, injuries in various parts of the lower extremity, and subgroup analysis for exercise frequency, exercise cycle, and exercise population. A total of 23 randomized controlled trial (RCT) studies were found to be included in the meta-analysis, and 15 of these trials, totaling 14,721 patients, were determined to be included in the overall lower extremity injury prevention effect. The analysis showed that the implementation of a hamstring eccentric training program reduced lower extremity injuries by 28%, and it resulted in a 46% decrease in hamstring injury rate and a 34% decrease in knee injury rate. The subgroup analysis revealed that the frequency of exercise was most significant in the twice-a-week exercise group, that the exercise program was most effective in preventing injuries in the 21–30-week exercise period, and that the program was most effective in preventing injuries in elite athletes and amateur adult athletic populations, compared with adolescents.
... de PEDro (20,21,23), mientras que los dos restantes se evaluaron 230 manualmente (22,24). Los artículos presentaron una puntuación entre 5 y 8, 231 clasificando 1 artículo como justo (21) y 4 como buenos (20,(22)(23)(24). ...
... de PEDro (20,21,23), mientras que los dos restantes se evaluaron 230 manualmente (22,24). Los artículos presentaron una puntuación entre 5 y 8, 231 clasificando 1 artículo como justo (21) y 4 como buenos (20,(22)(23)(24). Ningún 232 estudio cegó a los sujetos ni a los terapeutas (20-24), uno de ellos no estableció 233 los criterios de elegibilidad (20), otro no realizó asignación oculta, otro más no 234 presentó una comparativa basal (23), mientras que tres estudios no cegaron a 235 los evaluadores (20)(21)(22) ...
... La calidad metodológica se evaluó a través de la escala de PEDro. De los artículos incluidos en la revisión, tres contaban con calificación en la plataforma de PEDro (20,21,23), mientras que los dos restantes se evaluaron manualmente (22,24). Los artículos presentaron una puntuación entre 5 y 8, clasificando 1 artículo como justo (21) y 4 como buenos (20,(22)(23)(24). ...
Article
Full-text available
Introducción: Las lesiones musculares son comunes en futbolistas, siendo la lesión de isquiotibiales la más frecuente. Objetivo: Analizar la evidencia existente sobre los efectos de los ejercicios nórdicos en la incidencia de lesiones de isquiotibiales en jugadores de fútbol profesional y amateur masculinos entre los 15 y 41 años. Materiales y métodos: Se llevó a cabo una revisión sistemática siguiendo las recomendaciones de la declaración PRISMA, realizando la búsqueda de artículos en PubMed, BVS, Cochrane, Web OF Science y SCOPUS, además de consultar Google Scholar. La búsqueda se realizó basada en la estrategia PICO con los siguientes términos: hamstring muscles, exercise, rehabilitation, therapy, athletic injuries, soccer. Resultados: un total de 257 artículos resultaron de la búsqueda, siendo 5 los artículos incluidos en este estudio. Todos los estudios evidenciaron efectos positivos de los ejercicios nórdicos para los deportistas. Conclusiones: los ejercicios nórdicos redujeron la incidencia de lesión de isquiotibiales en 4 de los estudios analizados, el porcentaje de cumplimiento de las sesiones de intervención condicionaron la calidad de los efectos mientras que el momento de aplicación de la intervención (pre- o post-entreno) no influyó.
... In 2004, Mjølsnes et al. [12] introduced a 10-week progressive NHE training regimen, which has become the most replicated intervention program in published research [5,11,13,25,28,29,31,34,36,37,43,[54][55][56][57][58][59][60]. However, this particular study suffers from a substantial lack of information about NHE execution quality [61]. ...
... However, the full potential of such complex training programs will only be realized if each single exercise is regularly adopted, correctly executed, progressed, and sustained by their intended end users [39,[92][93][94]. Further, 22% of the included NHE interventions [5,11,13,25,28,29,31,34,36,37,43,[54][55][56][57][58][59][60] implemented the intervention protocol of Mjølsnes et al. published in 2004 [12] (Supplement Table S2), although it is doubtful whether progression via exercise volume is an expedient means to elicit the largest adaptations [7,8,64]. Due to the high amount of additional stress and accumulated fatigue which is induced by this strenuous exercise, regular NHE exposure with unnecessarily high exercise volumes-39% of NHE interventions conducted ≥8 repetitions/set (Figure 2b)-might potentially have a negative rather than a positive effect on injury risk mitigation and performance [42]. ...
Article
Full-text available
ABSTRACT: The objective of this scoping review is to assess Nordic Hamstring Exercise quality (ANHEQ) of assessments and interventions according to the ANHEQ rating scales and to present practical recommendations for the expedient design and reporting of future studies. A total of 71 Nordic Hamstring Exercise (NHE) assessments and 83 NHE interventions were selected from the data sources PubMed, Scopus, and SPORTDiscus. Research studies which were presented in peer-reviewed academic journals and implemented the NHE during laboratory-based assessments or multi-week interventions met the eligibility criteria. NHE assessments analyzed force (51%), muscle activation (41%), knee angle kinematics (38%), and bilateral symmetry (37%). NHE interventions lasted 4–8 weeks (56%) and implied an exercise volume of two sessions per week (66%) with two sets per session (41%) and ≥8 repetitions per set (39%). The total ANHEQ scores of the included NHE assessments and interventions were 5.0 ± 2.0 and 2.0 ± 2.0 (median ± interquartile range), respectively. The largest deficits became apparent for consequences of impaired technique (87% 0-point-scores for assessments) and kneeling height (94% 0-point-scores for interventions). The 0-point-scores were generally higher for interventions compared to assessments for rigid fixation (87% vs. 34%), knee position (83% vs. 48%), kneeling height (94% vs. 63%), and separate familiarization (75% vs. 61%). The single ANHEQ criteria, which received the highest score most frequently, were rigid fixation (66% of assessments) and compliance (33% of interventions). The quality of NHE assessments and interventions was generally ‘below average’ or rather ‘poor’. Both NHE assessments and interventions suffered from imprecise reporting or lacking information regarding NHE execution modalities and subsequent analyses. Based on the findings, this scoping review aggregates practical guidelines how to improve the design and reporting of future NHE-related research.
... In 2004, Mjølsnes et al. [12] introduced a 10-week progressive NHE training regimen, which has become the most replicated intervention program in published research [5,11,13,25,28,29,31,34,36,37,43,[54][55][56][57][58][59][60]. However, this particular study suffers from a substantial lack of information about NHE execution quality [61]. ...
... However, the full potential of such complex training programs will only be realized if each single exercise is regularly adopted, correctly executed, progressed, and sustained by their intended end users [39,[92][93][94]. Further, 22% of the included NHE interventions [5,11,13,25,28,29,31,34,36,37,43,[54][55][56][57][58][59][60] implemented the intervention protocol of Mjølsnes et al. published in 2004 [12] (Supplement Table S2), although it is doubtful whether progression via exercise volume is an expedient means to elicit the largest adaptations [7,8,64]. Due to the high amount of additional stress and accumulated fatigue which is induced by this strenuous exercise, regular NHE exposure with unnecessarily high exercise volumes-39% of NHE interventions conducted ≥8 repetitions/set (Figure 2b)-might potentially have a negative rather than a positive effect on injury risk mitigation and performance [42]. ...
Preprint
OBJECTIVE: Assessing Nordic Hamstring Exercise quality (ANHEQ) of assessments and interventions according to the ANHEQ rating scales and to present practical recommendations for the expedient design and reporting of future studies. DESIGN: Scoping review of 71 NHE assessments and 83 NHE interventions (12 of 131 full-text articles were applicable to both categories). DATA SOURCES: PubMed, MEDLINE and SPORTDiscus. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Research studies which were presented in peer-reviewed academic journals and implemented the NHE during laboratory-based assessments or multi-week interventions. RESULTS: The total ANHEQ scores of the analysed NHE assessments and interventions were 5.0±2.0 and 2.0±2.0 (median±IQR), respectively. Largest deficits became apparent for consequences of impaired technique (87% 0-point-scores for assessments) and kneeling height (94% 0-point-scores for interventions). The single ANHEQ criteria which received the highest score most frequently were rigid fixation (66% of assessments) and compliance (33% of interventions). CONCLUSIONS: The quality of NHE assessments and interventions was generally ‘below average’ or rather ‘poor’. Practitioners and scientists are encouraged to provide detailed information about their NHE modalities and about how their participants performed the exercise. The appropriate setup is suggested to be essential for best possible NHE performance and neuromuscular adaptations. NHE assessments should present comprehensive kinematic and kinetic data of supramaximal NHE performance, whereas NHE interventions should focus on exercise intensity and the implementation of facilitations. This scoping review aggregates practical guidelines how to improve the design and reporting of future NHE assessments and interventions to overcome the revealed limitations of current NHE-related evidences.
... For the analyses of the original data extraction, as in the previous meta-analysis, 7 the weighted raw point estimate for the Risk Ratios (RR) was calculated using a random-effects model, with DerSimonian and Laird estimator for the t-statistic, and Mantel-Haenszel estimator used in calculation of Q-statistic plus continuity correction of 0.5 in studies with zero cell frequencies. 26 For the analyses of the updated data extraction, including a recent RCT, 27 we estimated the mean summary effect using a random-effects model with Hartung-Knapp adjustment and Restricted Maximum-Likelihood Estimator (REML) estimator for the t-statistic relevant to small-to-medium scale meta-analyses with rare events. [28][29][30] We used the generalised Q-statistic method to describe the uncertainty around the mean -statistic value. ...
... Forest plot of the selected randomised controlled trials plus a recent additional study (Hasebe et al., 2020) using the Nordic hamstring exercise as independent variable (non-parametric 95% prediction interval, 0.17 to 1.52). ...
Article
Objective The Nordic hamstring exercise (NHE) is strongly recommended to reduce hamstring injuries in previous meta-analyses (50% reduction in risk of injury). To underline the importance and impact of adopting appropriate methodology for evidence synthesis, we revisited the study selection, re-analysed and updated the findings of the most recent meta-analysis. Study design and setting Only randomised control trials (RCT) using NHE as one of the prevention arms were selected. Summary effects for risk ratios (RR) for original studies included in the earlier meta-analysis, and new studies identified (update), were re-estimated under the random-effects model and presented with 95% confidence intervals (CI) and prediction intervals (PI). Tentative recommendations were provided according to the GRADE. Results Only five RCTs out of the 15 studies included in the earlier meta-analysis randomized to NHE. Our update revealed one additional RCT. The point estimate (RR) for the five RCTs previously considered RCTs was 0.56 (95%CI, 0.20 to 1.52; 95%PI, 0.06 to 5.14, parametric, and 0.13 to 1.80, nonparametric). After the update, the RR was 0.59 (95%CI, 0.27 to 1.29; 95%PI 0.10 to 3.29, parametric, and 0.17 to 1.52, nonparametric). Conclusions Contrary to the conclusions of a recent meta-analysis, as well as earlier meta-analyses, by using more appropriate methodology, the evidence underpinning the protective effect of NHE so far remains inconclusive and mostly derived from high risk of bias RCTs. At best, only conditional recommendation can be provided (for soccer) and future RCTs are warranted.
... Another alternative method used to assess maximal hamstring strength is the Nordic hamstring exercise (NHE). The NHE is a simple, very common and frequently used bilateral exercise in which the subject starts kneeling and attempts to resist a forward-falling motion [20][21][22]. Lodge et al. [23] found that the NHE test is a reliable and valid alternative to isokinetic tests for assessing maximal bilateral eccentric hamstring strength in adults. Although isokinetic tests are considered to be the best tests for evaluating maximal hamstring strength [15], eccentric and isometric tests seem to yield maximal leg flexion strength results more similar to the physical demands required during alpine ski racing, during which slow lengthening contractions are predominant on the inside leg and minor changes in knee angle and therefore almost constant muscle-tendon length, which means quasi-isometric work of the muscles on the outside leg [24,25]. ...
... The measured values in the present study are similar to the results reported by Franchi et al. [21], which were 210 N (±44) for the right leg and 207 N (±46) for the left leg in youth female ski racers and 259 N (±51) for the right leg and 258 N (±57) for the left leg in youth male ski racers (U15). Studies by other authors showed higher measured values of the absolute MBEHS (300-370 N) [38][39][40] than those reported in the present study. ...
Article
Full-text available
Background: Physical fitness is an important component in the development of youth alpine ski racers. To write systematically planned and age-appropriate fitness programs athletes need to be physically tested at regular intervals at an early age. Although well-developed hamstring muscle strength is important for alpine ski racing performance and the prevention of serious knee injuries, it has not been well investigated, especially in youth athletes. Accordingly, the first aim of the present study was to assess the test-retest reliability of the maximum bilateral eccentric (MBEHS) and unilateral isometric (MUIHS) hamstring tests. The second aim of the present study was to assess whether the results of these two methods correlate and if it is possible to commit to one of the two methods to provide an economic test procedure. Methods: The first study included 26 (14 females/12 males) youth alpine ski racers aged between 12 and 13 years. All athletes performed two MBEHS and two MUIHS tests, 7 days apart. The intraclass correlation coefficient (ICC 3,1) and their 95% confidence intervals based on a consistency two-way mixed model were used to estimate the reliability of the two different test modalities. The second study included 61 (27 females/34 males) youth alpine ski racers aged between 10 and 13 years. All athletes performed one MBEHS and one MUIHS test. Bland-Altman plots and the 95% limits of agreement as well as correlations by Pearson (r) between the different test modalities were assessed. Results: In study 1 “poor” to “moderate” (MBEHS right leg 0.79 (0.58–0.90); left leg 0.83 (0.66–0.92); MUIHS right leg 0.78 (0.56–0.89); left leg 0.66 (0.37–0.83)) ICC values and 95% confident intervals were obtained. Standard error of measurement (SEM) between trails was between 18.3 and 25.1 N. Smallest detectable difference (SDD) was between 50.8 and 69.5 N. In study 2 mean differences between MBEHS and MUIHS was around 20 N with higher values for MBEHS. Significant moderate-to-strong correlations were found between the test modalities (r = 0.74–0.84, p <0.001). Conclusions: The MBEHS test has higher ICC values, lower CV values, higher SEM values and lower SDD values than the MUIHS test. All this suggests that the MBEHS test is more suitable than the MUIHS test to determine the maximum hamstring force in young alpine ski racers.
... Injury risk also decreased in studies that included progressively difficult exercises and high compliance. (10,(14)(15)(16)(17)(18) More research is needed to better understand effective methods for HSI prevention. Specifically, more randomized controlled trials in a variety of soccer leagues across different divisions. ...
... Injury risk also decreased in studies that included progressively difficult exercises and high compliance. (10,(14)(15)(16)(17)(18) More research is needed to better understand effective methods for HSI prevention. Specifically, more randomized controlled trials in a variety of soccer leagues across different divisions. ...
... International Journal of Sports Physical Therapy the severity of hamstring injuries. 32 The number of cases categorized according to higher severity of injury is small in the current study, hence further study is required to determine the effect of CAE on injury severity. Comparing intervention groups, A and B, the number of groin pain injuries was lower in group B. Furthermore, the injury rate was lower in group B than in group A, but there was no significant difference in RR. ...
Article
Full-text available
Background Groin pain is frequently reported by soccer players. A prevention program incorporating the Copenhagen adduction exercise (CAE) has been shown effective in decreasing adductor muscle injury in semi-professional soccer players. However, the effect of such programs on groin pain in high school soccer players is unknown. No reports have examined the effects of combining the CAE with other targeted exercises such as the Nordic hamstrings exercise (NHE). Purpose To evaluate the preventative effects of exercise on groin pain in high school soccer players in three groups comprising NHE alone, combined NHE and CAE, and a control group. Design Randomized Controlled Clinical Trial. Methods A cluster randomized controlled trial spanning 16 weeks was conducted on 202 high school soccer players from seven high schools in a Japanese under 18 Soccer League. Players were allocated to either group A (three schools, 66 players) receiving the CAE alone, or group B (two schools, 73 players) receiving the CAE and NHE, or control group C (two schools, 63 players) who performed their usual training. This study compared the number of injuries, injury rate, and severity of the injury of groin pain in these three groups. Results The number of players injured was less in group B (4 players) compared to C (18 players), and time-lost to soccer was less in groups A (6 players) and B (3 players) compared to group C (16 players). Injury rates were significantly lower in groups A and B, with the relative risk of injury compared to group C of 0.42 (95% CI 0.19% to 0.90%) in group A and 0.19 (95% CI 0.07 to 0.54) in group B. Conclusion A 16-week program incorporating the CAE in training sessions in high school soccer players reduced the incidence of groin pain and which may be related to injury severity according to time -lost to soccer, however the combination of both the CAE and NHE may be more effective than the CAE alone. Level of Evidence 2b
... Several studies provided direct supervision of athletes, this included sports coaches or physical therapists, who were provided training by the investigators in how to perform the exercises prior to commencing the intervention, reporting moderate to very high levels of compliance (59.4-100.0%) [4,6,39,42,44,45,48]. Although the quality and reported compliance varied between the studies, the effect of regular and consistent feedback received from: sports coaches, strength and conditioning coaches, physical therapists, physicians, or peers, should not be underestimated in the role for a positive change. ...
Article
Full-text available
Eccentric strength training can reduce the risk of hamstring strain injury (HSI) occurrence; however, its implementation can be impacted by athlete compliance and prescription. The aim of this review was to investigate the effects of intervention compliance, consistency and modality, on the prevention of HSIs among athletes. A literature search was conducted. 868 studies were identified prior to the application of the exclusion criteria which resulted in 13 studies identified. Random effects models were used to produce log odds ratios and 95% confidence intervals. Very high (>75.1%), moderate-high (50.1–75%), low-moderate (25.1–50%) and very low (<25%) and <1-, 1.01–3.00-, >3.01-weeks/session were used as thresholds of compliance and consistency, respectively. Modality was also observed. A positive effect on HSI incidence -0.61 (−1.05 to −0.17), favoring the intervention treatments (Z = −2.70, p = 0.007). There were non-significant, large differences between compliance (p = 0.203, Z = −1.272) and consistency (p = 0.137, Z = −1.488), with increased compliance and consistency showing greater effectiveness. A significant difference between intervention modalities was observed (p < 0.001, Z = −4.136), with eccentric interventions being superiorly effective. Compliance of >50.1% and consistent application with <3 weeks/session having positive effects on HSI incidence. Training interventions that can achieve high levels of compliance, and can be consistently performed, should be the objective of future practice.
... Our findings align with a randomized controlled trial conducted to investigate the effects of Nordic Hamstring Exercise (NHE) on hamstring injuries in highschool soccer players. The authors reported a compliance rate with the NHE of 88% (22). However, the implementation rates reported in the current study are still better than those reported by Bahr et al (23). ...
Article
Full-text available
Background. Groin injuries are frequent and commonly seen in soccer. The Copenhagen Adduction Exercise (CAE) increases eccentric hip adduction strength and reduces the groin injury incident. Objectives. To assess the professional and semi-professional soccer players and coaches' awareness, implementation, and opinion of the CAE. Methods. A cross-sectional study based on a survey consisting of questions covering the awareness, implementation, and opinion of CAE by soccer players and coaches. It was sent to all FIFA continental football federations. Primary outcomes were awareness level, implementation rate, and their view of the CAE's effectiveness in reducing groin injury. Results. A total of 1621 male and female professional and semi-professional soccer players (PP and SPP) and coaches (PC and SPC) completed the survey. Most PP (93.5%) and SPP (81.4%) were unaware of the CAE (P < 0.001), with high implementation rates (P = 0.005). In contrast, the PC had significantly higher awareness about the CAE than the SPC (P < 0.001). A moderate association between the level and awareness (Cramér's V = 0.340) was found. The highest percentage of awareness was found in the UEFA at 42.6%. Over 67% of those who implemented the CAE reported a positive attitude about the program efficacy, with a score of >8 out of 10. Conclusion. Most PP, SPP, and SPC were unaware of the CAE. Further work needs to be done to educate soccer players and coaches about the importance of implementing the CAE and its effectiveness in reducing groin injuries to enhance the CAE implementation.
... The included studies were conducted in the USA, 33 40 Norway, 23 41 the Netherlands, 24 42 Germany, 43 Japan, 44 Nigeria 45 and Sweden. 46 Six studies included only male football players 24 40 42-45 and four included only female football players, 23 33 41 46 and the total sample sizes for intervention and control groups were 6900 and 6455, respectively. ...
Article
Full-text available
Objective The aim of this systematic review was to investigate the effect of exercise-based programmes in the prevention of non-contact musculoskeletal injuries among football players in comparison to a control group. Design Systematic review and meta-analysis of randomised controlled trials. Data sources MEDLINE, EMBASE, CENTRAL, CINAHL, PEDro and SPORTDiscus databases were searched from the earliest record to January 2021. Eligibility criteria Studies were eligible if they (1) included football players aged 13 years or older, (2) used exercise-based programmes as intervention, (3) presented the number of non-contact musculoskeletal injuries (ie, defined as any acute sudden onset musculoskeletal injury that occurred without physical contact) and exposure hours for each group, and (4) had a control group (eg, usual training, minimal intervention, education). All types of exercise-based prevention programmes were eligible for inclusion. Risk of bias for each included study and overall quality of evidence for the meta-analysis were assessed. Results Ten original randomised controlled trials with 13 355 football players and 1 062 711 hours of exposure were selected. Pooled injury risk ratio showed very low-quality evidence that exercise-based prevention programmes reduced the risk of non-contact musculoskeletal injuries by 23% (0.77 (95% CI 0.61 to 0.97)) compared with a control group. Conclusion Exercise-based prevention programmes may reduce the risk of non-contact musculoskeletal injuries by 23% among football players. Future high-quality trials are still needed to clarify the role of exercise-based programmes in preventing non-contact musculoskeletal injuries among football players.
... In line with this data, a randomized controlled trial on the effects of NHE on hamstring injuries in high-school soccer players showed that the compliance rate with the NHE was 88%. 16 In contrast, it was reported that there is a large disconnect between the available evidence of NHE efficacy and its adoption in elite football, and the overall compliance level was not encouraging. 17,18 Bahr et al. (2015) published a study that showed that only 11% of the teams fully adopted the program. ...
Article
Full-text available
Background/Purpose In soccer players, non-contact injuries are most common, especially hamstring muscle injuries, which can be prevented by the Nordic hamstring exercise (NHE). This study assessed the professional and semi-professional soccer players and coaches’ awareness, implementation, and opinion of the NHE efficacy in reducing hamstring injuries. Methods A questionnaire regarding the awareness, implementation, and opinions of the NHE’s efficacy in reducing hamstring muscle injuries was distributed. Results The survey was completed by 812 (88.3% male and 11.7% female) players and coaches. Of these, 395 (48.6%) were aware of the NHE, and 355 (43.7%) implemented it in their current practice. Those implementing NHE had a positive opinion about its efficacy in reducing hamstring injuries. Conclusion Further efforts and research are warranted to increase the international awareness and implementation of the NHE and educate soccer players and coaches about the importance of its implementation and effectiveness in preventing hamstring injury.
... The included studies were conducted in the USA, 33 40 Norway, 23 41 the Netherlands, 24 42 Germany, 43 Japan, 44 Nigeria 45 and Sweden. 46 Six studies included only male football players 24 40 42-45 and four included only female football players, 23 33 41 46 and the total sample sizes for intervention and control groups were 6900 and 6455, respectively. ...
... The NHE has also been shown to be preventive of hamstring injury in male soccer players. Looking a 259 players, Hasebe et al. compared a NHE group to a control group not using the NHE but matched for all other training variables (12). Over a 27-week period the injury rate per 10,000 playing hours of the control group was 1.04/10,000 h but down to 0.88/10,000 h in the NHE group, resulting in a significant reduction in time lost. ...
Article
Full-text available
Hamstring injuries are common in sport, as are injury recurrence rates. Hamstring injury rehabilitation requires a multifactorial approach involving the lower spine and pelvis, neuromobilisation and hamstring lengthening and strengthening. This article sets out the aspects that need to be addressed and how to address them so that you will be able to create a personalised hamstring rehab programme that will give your patient the strength and confidence for the best quality return to play
Article
Full-text available
Hamstring strain injury (HSI) may result in considerable impairment, activity limitation, and participation restriction, including time lost from competitive sports. This CPG includes sports-related overloading and overstretching injuries to myofascial or musculotendinous structures in any combination of the 3 hamstring muscles (the semitendinosus, semimembranosus, and biceps femoris). J Orthop Sports Phys Ther, Epub 14 Feb 2022. doi:10.2519/jospt.2022.0301.
Article
Full-text available
The aim of this study was to describe the changes in body composition, strength and sprint performance in response to an entire competitive season of football training supplemented with 2 inertial eccentric-overload training sessions a week in young male professional soccer players. Whole body and regional composition (assessed using dual-energy X-ray absorpti-ometry), power output in half-squat and 40-m sprinting performance were evaluated in fourteen players. The eccentric-overload training consisted of training sessions a week of 1-2 sets of 10 exercises of upper-body and core (Day 1) and lower-body (Day 2), during the entire competitive season (27 weeks). Whole body fat mass decreased (-6.3 ± 3.6%, ES =-0.99 ± 0.54) substantially while lean mass increased (2.5 ± 0.8%, ES = 0.25 ± 0.09), with some regional differences. There was a substantial increase in half-squat power output (from 3% to 14%, ES from 0.45 to 1.73) and sprint performance (from 1.1% to 1.8%, ES from-0.33 to-0.44), however performance changes were not correlated with changes in body composition. A combined soccer and eccentric-overload training program was able to promote positive changes in body composition and physical factors relevant to both on-field performance and injury prevention in elite soccer players.
Article
Full-text available
Question: Does adding a post-training Fédération Internationale de Football Association (FIFA) 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduce injury rates among male amateur soccer players? Design: Cluster-randomised, controlled trial with concealed allocation. Participants: Twenty-one teams of male amateur soccer players aged 14 to 35 years were randomly assigned to the experimental group (n=10 teams, 160 players) or the control group (n=11 teams, 184 players). Intervention: Both groups performed pre-training FIFA 11+ exercises for 20minutes. The experimental group also performed post-training FIFA 11+ exercises for 10minutes. Outcome measures: The primary outcomes measures were incidence of overall injury, incidence of initial and recurrent injury, and injury severity. The secondary outcome measure was compliance to the experimental intervention (pre and post FIFA 11+ program) and the control intervention (pre FIFA 11+ program). Results: During one season, 26 injuries (team mean=0.081 injuries/1000 exposure hours, SD=0.064) were reported in the experimental group, and 82 injuries were reported in the control group (team mean=0.324 injuries/1000hours, SD=0.084). Generalised Estimating Equations were applied with an intention-to-treat analysis. The pre and post FIFA 11+ program reduced the total number of injuries (χ(2) (1)=11.549, p=0.001) and the incidence of initial injury (χ(2) (2)=8.987, p=0.003) significantly more than the pre FIFA 11+ program alone. However, the odds of suffering a recurrent injury were not different between the two groups (χ(2) (1)=2.350, p=0.125). Moreover, the severity level of injuries was not dependent upon whether or not the pre and post FIFA 11+ program was implemented (χ(2) (1)=0.016, p=0.898). Conclusion: Implementation of the FIFA 11+ program pre-training and post-training reduced overall injury rates in male amateur soccer players more than the pre FIFA 11+ program alone. Trial registration: ACTRN12615001206516. [Al Attar WSA, Soomro N, Pappas E, Sinclair PJ, Sanders RH (2017) Adding a post-training FIFA 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduces injury rates among male amateur soccer players: a cluster-randomised trial. Journal of Physiotherapy XX: XX-XX].
Article
Full-text available
The ideal implementation of soccer injury prevention programs is essential knowledge for soccer coaches. The objective of this study was to investigate and compare the implementation of injury prevention programs, specially the FIFA 11+ program, among Australian and Saudi Arabian soccer coaches. A Web-based survey was used to obtain information regarding the coaches’ implementation of injury prevention programs, the FIFA 11+ program, the Nordic hamstring exercise, pre and post-training exercises. Sixty coaches - 30 from both selected countries - responded to the survey (response rate = 75 %). In Australia, 93 % of the coaches implemented an injury prevention program; while 73 % implemented the FIFA 11+ program, only 51 % implemented all the FIFA 11+ exercise components as recommended. In Saudi Arabia, 70 % of the coaches stated that they followed an injury prevention program, but only 40 % followed the FIFA 11+ program. However, 70 % reported using all the FIFA 11+ exercise components in their current practices, which they may have adapted from different exercise-based injury prevention programs. The Australian coaches were significantly more likely to implement injury prevention programs (p = 0.020) and the FIFA 11+ program (p = 0.009). Nonetheless, no significant difference in the full implementation of the FIFA 11+ exercises components was found (p = 0.114). The Australian coaches had greater awareness of injury prevention programs and more familiarity with the FIFA 11+ program than the Saudi Arabian coaches. Nevertheless, there was a gap between the coaches’ knowledge and their actual practice. Keywords: Soccer coaches; Injury prevention programs; FIFA 11+ program; Nordic hamstring exercise; Pre-training exercises; Post-training exercises.
Article
Full-text available
Background Hamstring injuries are among the most common non-contact injuries in sports. The Nordic hamstring (NH) exercise has been shown to decrease risk by increasing eccentric hamstring strength. Objective The purpose of this systematic review and meta-analysis was to investigate the effectiveness of the injury prevention programs that included the NH exercise on reducing hamstring injury rates while factoring in athlete workload. Methods Two researchers independently searched for eligible studies using the following databases: the Cochrane Central Register of Controlled Trials via OvidSP, AMED (Allied and Complementary Medicine) via OvidSP, EMBASE, PubMed, MEDLINE, SPORTDiscus, Web of Science, CINAHL and AusSportMed, from inception to December 2015. The keyword domains used during the search were Nordic, hamstring, injury prevention programs, sports and variations of these keywords. The initial search resulted in 3242 articles which were filtered to five articles that met the inclusion criteria. The main inclusion criteria were randomized controlled trials or interventional studies on use of an injury prevention program that included the NH exercise while the primary outcome was hamstring injury rate. Extracted data were subjected to meta-analysis using a random effects model. ResultsThe pooled results based on total injuries per 1000 h of exposure showed that programs that included the NH exercise had a statistically significant reduction in hamstring injury risk ratio [IRR] of 0.490 (95 % confidence interval [CI] 0.291–0.827, p = 0.008). Teams using injury prevention programs that included the NH exercise reduced hamstring injury rates up to 51 % in the long term compared with the teams that did not use any injury prevention measures. Conclusions This systematic review and meta-analysis demonstrates that injury prevention programs that include NH exercises decrease the risk of hamstring injuries among soccer players. A protocol was registered in the International Prospective Register of Systematic Reviews, PROSPERO (CRD42015019912).
Article
Full-text available
Hamstring injuries are the most common muscle injuries in male amateur soccer. Eccentric strength of the hamstrings is recognized as an important modifiable risk factor, leading to the development of preventive exercises such as the Nordic Hamstring Exercise. This study aims to investigate the preventive effect of the Nordic Hamstring Exercise on the incidence and severity of hamstring injuries in male amateur soccer players. Cluster-randomized controlled trial with soccer teams as the unit of cluster. Dutch first class amateur field soccer. Male amateur soccer players (mean age 24.5 years, SD 3.8 years) from 40 teams were allocated to intervention (n=309 players) or control group (n=310 players). The intervention group was instructed to perform 25 sessions of the Nordic Hamstring Exercise within a period of 13 weeks during the first months of 2013. Both the intervention group and control group performed regular soccer training and were followed for hamstring injury incidence and severity during the calendar year 2013. At baseline, personal characteristics (e.g. age, injury history, field position) were gathered from all participants via questionnaire. Primary outcomes are initial and recurrent hamstring injury incidence (number of hamstring injuries) and injury severity (number of days injured). Interim analysis after intervention (2 months follow-up) show a total of 2 hamstring injuries in intervention group vs 12 hamstring injuries in control group (χ(2)=7.5, P<.05). Regarding injury severity, no difference was found between intervention and control group (t=0.3, P=.77). Preliminary analyses during the summer break show substantial hamstring injury incidence reduction by incorporating the Nordic Hamstring Exercise in regular training. With a total follow-up of 9 months, final analyses (survival analyses including the number of injuries per 1000 playing hours) will be performed in January 2014.
Article
Full-text available
Objective: to compare the incidence and characteristics of injuries between Dutch amateur and professional male soccer players during one entire competition season. Design: a prospective two-cohort design. Methods: during the 2009-2010 season, 456 Dutch male amateur soccer players and 217 professional players were prospectively followed. Information on injuries and individual exposure to all soccer activities were recorded in both cohorts. Injuries were recorded using the time-loss definition. Results: In total, 424 injuries were recorded among 274 of the amateur players (60.1% injured players) and 286 injuries were sustained by 136 (62.7% injured players) of the professional players (p=0.52). Compared to the professionals, the injury incidence during training sessions was higher among amateurs (p=0.01), but the injury incidence among professionals was higher during matches (p<0.001). Professional players also had a higher incidence of minimal injuries (p<0.001), whereas the incidence of moderate and severe injuries was higher for amateurs (all p<0.001). Lastly, professional players sustained more overuse injuries (p=0.02), whereas amateurs reported more recurrent injuries (p<0.001). Conclusions: The abovementioned differences in injury rates between amateur and professional players in the Netherlands might be explained by the difference in the level at which they play, since factors like the availability of medical support and/or the team size may influence the injury risk and characteristics.
Article
Full-text available
Is an injury prevention program consisting of 10 exercises designed to improve stability, muscle strength, co-ordination, and flexibility of the trunk, hip and leg muscles (known as The11) cost effective in adult male amateur soccer players? Cost-effectiveness analysis of a cluster-randomised controlled trial. 479 adult male amateur soccer players aged 18-40 years. The intervention group was instructed to perform the exercises at each training session (2 to 3 sessions per week) during one soccer season. The exercises focus on core stability, eccentric training of thigh muscles, proprioceptive training, dynamic stabilisation, and plyometrics with straight leg alignment. The control group continued their usual warm-up. All injuries and costs associated with these injuries were compared between groups after bootstrapping (5000 replications). No significant differences in the proportion of injured players and injury rate were found between the two groups. Mean overall costs in the intervention group were €161 (SD 447) per athlete and €256 (SD 555) per injured athlete. Mean overall costs in the control group were €361 (SD 1529) per athlete and €606 (SD 1944) per injured athlete. Statistically significant cost differences in favour of the intervention group were found per player (mean difference €201, 95% CI 15 to 426) and per injured player (mean difference €350, 95% CI 51 to 733). The exercises failed to significantly reduce the number of injuries in male amateur soccer players within one season, but did significantly reduce injury-related costs. The cost savings might be the result of a preventive effect on knee injuries, which often have substantial costs due to lengthy rehabilitation and lost productivity. Trial registration: NTR2416. [Krist MR, van Beijsterveldt AMC, Backx FJG, de Wit GA (2013) Preventive exercises reduced injury-related costs among adult male amateur soccer players: a clusterrandomised trial.Journal of Physiotherapy59: 15-23].
Article
Full-text available
Muscle injuries constitute a large percentage of all injuries in football. To investigate the incidence and nature of muscle injuries in male professional footballers. Cohort study; Level of evidence, 2. Fifty-one football teams, comprising 2299 players, were followed prospectively during the years 2001 to 2009. Team medical staff recorded individual player exposure and time-loss injuries. The first-team squads of 24 clubs selected by the Union of European Football Associations as belonging to the best European teams, 15 teams of the Swedish First League, and another 15 European teams playing their home matches on artificial turf pitches were included. A muscle injury was defined as "a traumatic distraction or overuse injury to the muscle leading to a player being unable to fully participate in training or match play." In total, 2908 muscle injuries were registered. On average, a player sustained 0.6 muscle injuries per season. A squad of 25 players can thus expect about 15 muscle injuries per season. Muscle injuries constituted 31% of all injuries and caused 27% of the total injury absence. Ninety-two percent of all muscle injuries affected the 4 major muscle groups of the lower limbs: hamstrings (37%), adductors (23%), quadriceps (19%), and calf muscles (13%). Sixteen percent of the muscle injuries were reinjuries. These reinjuries caused significantly longer absences than did index injuries. The incidence of muscle injury increased with age. When separated into different muscle groups, however, an increased incidence with age was found only for calf muscle injuries and not for hamstring, quadriceps, or hip/groin strains. Muscle injuries are a substantial problem for players and their clubs. They constitute almost one third of all time-loss injuries in men's professional football, and 92% of all injuries affect the 4 big muscle groups in the lower limbs.
Article
Full-text available
Data on the incidence, nature, severity and cause of match football injuries sustained on dirt field are scarce. The objectives of this study was to compare the incidence, nature, severity and cause of match injuries sustained on dirt field and artificial turf field by amateur male football players. A prospective two-cohort design was employed. Participants were 252 male football players (mean age 27 years, range 18-43) in 14 teams who participated in a local championship carried on a dirt field and 216 male football players (mean age 28 years, range 17-40) in 12 teams who participated in a local championship carried on a artificial turf field in the same zone of the city. Injury definitions and recording procedures were compliant with the international consensus statement for epidemiological studies of injuries in football. The overall incidence of match injuries for men was 36.9 injuries/1000 player hours on dirt field and 19.5 on artificial turf (incidence rate ratio 1.88; 95% CI 1.19-3.05).Most common injured part on dirt field was ankle (26.7%) and on artificial turf was knee (24.3%). The most common injury type in the dirt field was skin injuries (abrasion and laceration) and in the artificial turf was sprain and ligament injury followed by haematoma/contusion/bruise.Most injuries were acute (artificial turf 89%, dirt field 91%) and resulted from player-to-player contact (artificial turf 59.2%, dirt field 51.4%).Most injuries were slight and minimal in dirt field cohort but in artificial turf cohort the most injuries were mild. There were differences in the incidence and type of football match injuries sustained on dirt field and artificial turf.
Article
Full-text available
In Switzerland, the national accident insurance company registered a total of 42 262 soccer injuries, resulting in costs of approximately 145 million Swiss francs (~US$130 million) in 2003. Research on injury prevention has shown that exercise-based programs can reduce the incidence of soccer injuries. This study was conducted to assess the implementation and effects of a countrywide campaign to reduce the incidence of soccer injuries in Swiss amateur players. Cohort study; Level of evidence, 3. All coaches of the Schweizerischer Fussballverband (SFV) received information material and were instructed to implement the injury prevention program "The 11" in their training of amateur players. After the instruction, the coaches were asked to rate the quality and the feasibility of "The 11." Before the start of the intervention and 4 years later, a representative sample of about 1000 Swiss soccer coaches were interviewed about the frequency and characteristics of injuries in their teams. Teams that did or did not practice "The 11" were compared with respect to the incidence of soccer injuries. A total of 5549 coaches for amateur players were instructed to perform "The 11" in the training with their teams. The ratings of the teaching session and the prevention program were overall very positive. In 2008, 80% of all SFV coaches knew the prevention campaign "The 11" and 57% performed the program or most parts of it. Teams performing "The 11" had an 11.5% lower incidence of match injuries and a 25.3% lower incidence of training injuries than other teams; noncontact injuries in particular were prevented by the program. "The 11" was successfully implemented in a countrywide campaign and proved effective in reducing soccer injuries in amateur players. An effect of the prevention program was also observed in the population-based insurance data and health-care costs.
Article
Full-text available
Unlabelled: Hamstring strain injuries remain a challenge for both athletes and clinicians, given their high incidence rate, slow healing, and persistent symptoms. Moreover, nearly one third of these injuries recur within the first year following a return to sport, with subsequent injuries often being more severe than the original. This high reinjury rate suggests that commonly utilized rehabilitation programs may be inadequate at resolving possible muscular weakness, reduced tissue extensibility, and/or altered movement patterns associated with the injury. Further, the traditional criteria used to determine the readiness of the athlete to return to sport may be insensitive to these persistent deficits, resulting in a premature return. There is mounting evidence that the risk of reinjury can be minimized by utilizing rehabilitation strategies that incorporate neuromuscular control exercises and eccentric strength training, combined with objective measures to assess musculotendon recovery and readiness to return to sport. In this paper, we first describe the diagnostic examination of an acute hamstring strain injury, including discussion of the value of determining injury location in estimating the duration of the convalescent period. Based on the current available evidence, we then propose a clinical guide for the rehabilitation of acute hamstring injuries, including specific criteria for treatment progression and return to sport. Finally, we describe directions for future research, including injury-specific rehabilitation programs, objective measures to assess reinjury risk, and strategies to prevent injury occurrence. Level of evidence: Diagnosis/therapy/prevention, level 5.
Article
Full-text available
Hamstring injuries are common in sprinters. Identifying preseason risk factors is essential to target injury-prone athletes and develop injury preventive measures. To investigate the incidence of hamstring muscle injury in sprinters over an athletic season and to explore the preseason predictor of this injury. Prospective cohort study. 44 sprinters from the Hong Kong Sports Institute, the Hong Kong Amateur Athletic Association and intercollegiate athletic teams were recruited. Preseason assessment of hamstring flexibility, concentric and eccentric isokinetic peak torque and peak torque angle were obtained at the beginning of an athletic season. The athletes were followed over 12 months and were asked to report all injuries resulting from training and competition. Eight athletes sustained hamstring injuries over the season. The injury rate was 0.87 per 1000 h of exposure. The incidence of injuries was higher at the beginning of the season, with 58.3% injuries occurring in the first 100 h of exposure. Cox regression analysis revealed that athletes with a decrease in the hamstring : quadriceps peak torque ratio of less than 0.60 at an angular velocity of 180 degrees/s have a 17-fold increased risk of hamstring injury. Performing preseason hamstring : quadriceps peak torque ratio assessments may be useful to identify sprinters susceptible to hamstring injury.
Article
Full-text available
To prospectively establish risk factors for hamstring muscle strain injury using magnetic resonance imaging (MRI) to define the diagnosis of posterior thigh injury. In a prospective cohort study using two elite Australian Rules football clubs, the anthropometric characteristics and past clinical history of 114 athletes were recorded. Players were followed throughout the subsequent season, with posterior thigh injuries being documented. Hamstring intramuscular hyperintensity on T2 weighted MRI was required to meet our criteria for a definite hamstring injury. Statistical associations were sought between anthropometric and previous clinical characteristics and hamstring muscle injury. MRI in 32 players showed either hamstring injury (n = 26) or normal scans (n = 6). An association existed between a hamstring injury and each of the following: increasing age, being aboriginal, past history of an injury to the posterior thigh or knee or osteitis pubis (all p<0.05). These factors were still significant when players with a past history of posterior thigh injury (n = 26) were excluded. Previous back injury was associated with a posterior thigh injury that looked normal on MRI scan, but not with an MRI detected hamstring injury. Hamstring injuries are common in Australian football, and previous posterior thigh injury is a significant risk factor. Other factors, such as increasing age, being of aboriginal descent, or having a past history of knee injury or osteitis pubis, increase the risk of hamstring strain independently of previous posterior thigh injury. However, as the numbers in this study are small, further research is needed before definitive statements can be made.
Article
Full-text available
To describe the epidemiology of injuries in the Australian Football League (AFL) over four seasons. An injury was defined as "any physical or medical condition that caused a player to miss a match in the regular season." The rationale for this definition was to eliminate a previously noted tendency of team recorders to interpret injury definitions subjectively. Administrative records of injury payments to players who did not play matches determined the occurrence of an injury. The seasonal incidence of new injuries was 39 per club (of 40 players) per season (of 22 matches). The match injury incidence for AFL games was 25.7 injuries per 1000 player hours. The injury prevalence (percentage of players missing through injury in an average week) was 16%. The recurrence rate of injuries was 17%. The most common and prevalent injury was hamstring strain (six injuries per club per season, resulting in 21 missed matches per club per season), followed in prevalence by anterior cruciate ligament and groin injuries. The injury definition of this study does not produce incidence rates that are complete for all minor injuries. However, the determination of an injury is made by a single entity in exactly the same manner for all teams, which overcomes a significant methodological flaw present in other multiteam injury surveillance systems.
Article
Full-text available
Prospective randomized comparison of 2 rehabilitation programs. The objectives of this study were to compare the effectiveness of 2 rehabilitation programs for acute hamstring strain by evaluating time needed to return to sports and reinjury rate during the first 2 weeks and the first year after return to sport. A third objective was to investigate the relationship between functional testing performance and time to return to sports and reinjury rates after return to sport. Hamstring muscle strains are common in sports and often result in chronic pain, recurrent hamstring strains, and reduced sports performance. Current rehabilitation programs are primarily developed anecdotally and lack support from prospective, randomized research. Twenty-four athletes with an acute hamstring strain were randomly assigned to 1 of 2 rehabilitation groups. Eleven athletes were assigned to a protocol consisting of static stretching, isolated progressive hamstring resistance exercise, and icing (STST group). Thirteen athletes were assigned to a program consisting of progressive agility and trunk stabilization exercises and icing (PATS group). The number of days for full return to sports, injury recurrence within the first 2 weeks, injury recurrence within the first year of returning to sports, and lower-extremity functional evaluations were collected for all subjects and compared between groups. The average (+/- SD) time required to return to sports for athletes in the STST group was 37.4 +/- 27.6 days, while the average time for athletes in the PATS group was 22.2 +/- 8.3 days. This difference was not statistically significant (P = .2455). In the first 2 weeks after return to sports, reinjury rate was significantly greater (P = .00343, Fisher's exact test) in the STST group, where 6 of 11 athletes (54.5%) suffered a recurrent hamstring strain after completing the stretching and strengthening program, as compared to none of the 13 athletes (0%) in the PATS group. After 1 year of return to sports, reinjury rate was significantly greater (P = .0059, Fisher's exact test) in the STST group. Seven of 10 athletes (70%) who completed the hamstring stretching and strengthening program, as compared to only 1 of the 13 athletes (7.7%) who completed the progressive agility and trunk stabilization program, suffered a recurrent hamstring strain during that 1-year period. A rehabilitation program consisting of progressive agility and trunk stabilization exercises is more effective than a program emphasizing isolated hamstring stretching and strengthening in promoting return to sports and preventing injury recurrence in athletes suffering an acute hamstring strain. Future randomized clinical trials should investigate the potential for progressive agility and trunk stabilization programs in the prevention of hamstring strain injury during sports.
Article
Full-text available
Hamstring muscle strain is one of the most common injuries in sports. Still, knowledge is limited about the progression of clinical and magnetic resonance imaging characteristics and their association with recovery time in athletes. Knowing the anatomical location and extent of an acute first-time hamstring strain in athletes is critical for the prognosis of recovery time. Case series (prognosis); Level of evidence, 2. Eighteen elite sprinters with acute first-time hamstring strains were prospectively included in the study. All subjects were examined, clinically and with magnetic resonance imaging, on 4 occasions after injury: at day 2 to 4, 10, 21, and 42. The clinical follow-up period was 2 years. All sprinters were injured during competitive sprinting, and the primary injuries were all located in the long head of the biceps femoris muscle. There was an association between the time to return to pre-injury level (median, 16; range, 6-50 weeks) and the extent of the injury, as indicated by the magnetic resonance imaging parameters. Involvement of the proximal free tendon, as estimated by MRI, and proximity to the ischial tuberosity, as estimated both by palpation and magnetic resonance imaging, were associated with longer time to return to pre-injury level. Careful palpation during the first 3 weeks after injury and magnetic resonance imaging investigation performed during the first 6 weeks after injury provide valuable information that can be used to predict the time to return to pre-injury level of performance in elite sprinting.
Article
Background The architectural and morphological adaptations of the hamstrings in response to training with different exercises have not been explored. Purpose To evaluate changes in biceps femoris long head (BFLH) fascicle length and hamstring muscle size following 10-weeks of Nordic hamstring exercise (NHE) or hip extension (HE) training. Methods 30 recreationally active male athletes (age, 22.0±3.6 years; height, 180.4±7 cm; weight, 80.8 ±11.1 kg) were allocated to 1 of 3 groups: (1) HE training (n=10), NHE training (n=10), or no training (control, CON) (n=10). BFLH fascicle length was assessed before, during (Week 5) and after the intervention with a two-dimensional ultrasound. Hamstring muscle size was determined before and after training via MRI. Results Compared with baseline, BFLH fascicles were lengthened in the NHE and HE groups at mid-training (d=1.12-1.39, p<0.001) and post-training (d=1.77-2.17, p<0.001) and these changes did not differ significantly between exercises (d=0.49-0.80, p=0.279-0.976). BFLH volume increased more for the HE than the NHE (d=1.03, p=0.037) and CON (d=2.24, p<0.001) groups. Compared with the CON group, both exercises induced significant increases in semitendinosus volume (d=2.16-2.50, ≤0.002) and these increases were not significantly different (d=0.69, p=0.239). Conclusion NHE and HE training both stimulate significant increases in BFLH fascicle length; however, HE training may be more effective for promoting hypertrophy in the BFLH. © 2016 BMJ Publishing Group Ltd & British Association of Sport and Exercise Medicine.
Article
A study was conducted to determine the effect of aging on motor ability and to establish a test battery for physical fitness in the elderly. The subjects were 150 men aged 18 to 83 years. The test items examined were selected, according to Fleishman's list of motor abilities; (1) trunk flexion, (2) grip and isometric knee extension strength, (3) postural sway with eyes open and closed, (4) step test, (5) walking test at preferred and maximum speeds, (6) simple visual reaction time, (7) peg-board test, (8) finger tapping test at maximum rate and in time to metronome sounds. Performances for the test items, except for preferred walking speed and coefficient of variation in finger tapping at 5 Hz, showed significant decreases with aging. The decrease in motor performance at age 80 years relative to the level at age 20 years was less than 30% for finger dexterity and reaction time, 40-60% for muscle strength, maximum walking speed and the step test, and over 70% for trunk flexion and postural sway with eyes closed. A test battery composed of trunk flexion, grip strength, knee extension, step test, walking as fast as possible, postural sway with eyes closed, and finger tapping, is therefore recommended for assessing the effect of aging on physical fitness.
Article
Objectives: Although previous research shows that the hamstring length–tension relationship during eccentric contractions plays a role in hamstring injury, training methods to promote beneficial adaptations are still unclear. The purpose of this pilot study was to determine whether an eccentric hamstring specific training programme results in favourable adaptations. Design: Eccentric training consisting of the Nordic hamstring exercise performed twice a week for four weeks. Pre-and post-training concentric/concentric isokinetic testing of peak torque (PT) and position of peak torque (POS) was performed for both the quadriceps and hamstrings of both legs at 608 s K1 . Vertical jump height was also assessed. Participants: Nine athletic, male subjects with no previous strength training experience. Results: There was a significant increase in vertical jump height (preZ51.0G4.8 cm, postZ54.4G6.3 cm, pZ0.04), a significant reduction in quadriceps PT (preZ204.6G21.9 N.m., postZ181.5G19.9 N.m., pZ0.01), a significant decrease in hamstring POS from full knee extension (preZ32.5G7.48, postZ26.2G8.68, pZ0.01) and a significant hamstring POS difference between limbs (dominantZ33.8G9.58, non-dominantZ24.9G6.58, pZ0.01). Conclusion: Nordic hamstring exercise training may produce favourable neuromuscular adaptations for the possible prevention of hamstring injuries while enhancing performance in athletic, untrained males.
Article
Hamstring muscle strain-type injuries are common in sports that involve sprinting,1 acceleration, deceleration, rapid change in direction and jumping.2 ,3 Occurring in both recreational and professional sports, these injuries can result in substantial time lost from sport and commonly recur.4 ,5 In the Australian Football League (AFL), hamstring muscle strain-type injuries have displayed a high incidence rate, with a 10 year mean of 6.1 new injuries per club each year and a 23% average recurrence rate.6 A recurrence rate of 17% has been reported in elite soccer players7 with hamstring injuries also recorded as the most common injury accounting for 12% of all injuries and resulting in an average of four missed games per injury.8 The high incidence of hamstring muscle strain-type injuries and potential associated costs has resulted in a substantial amount of research into the factors related to such injuries. Two recent systematic reviews have been completed in an attempt to collate the evidence around risk factors for hamstring injuries.9 ,10 Both reviews identified hamstring muscle weakness and thigh muscle imbalance, muscle flexibility, previous hamstring injury, other previous injury and age as potential risk factors; however, these reviews concluded that single variables were inconsistently identified as associated factors. Both reviews provided a qualitative synthesis of the literature and included risk factor studies as well as intervention studies, where a potential risk factor was modified with a training programme. The inclusion of intervention studies may potentially complicate risk factor analyses, as such studies assume that the factor being modified is associated with the injury and that the factor can be modified by the treatment programme. The aim of the current review was to assemble all available knowledge and data to identify the intrinsic and extrinsic risk factors associated with …
Article
The incidence of acute hamstring injuries is high in several sports, including the different forms of football. The authors investigated the preventive effect of eccentric strengthening of the hamstring muscles using the Nordic hamstring exercise compared with no additional hamstring exercise on the rate of acute hamstring injuries in male soccer players. Randomized controlled trial; Level of evidence, 1. Fifty Danish male professional and amateur soccer teams (942 players) were allocated to an intervention group (461 players) or a control group (481 players). Players in the intervention group conducted a 10-week progressive eccentric training program followed by a weekly seasonal program, whereas players in the control group followed their usual training program. The main outcome measures were numbers of overall, new, and recurrent acute hamstring injuries during 1 full soccer season. Fifty-two acute hamstring injuries in the control group compared with 15 injuries in the intervention group were registered. Comparing intervention versus the control group, overall acute hamstring injury rates per 100 player seasons were 3.8 versus 13.1 (adjusted rate ratio [RR], 0.293; 95% confidence interval [CI], 0.150-0.572; P < .001). New injury rates per 100 player seasons were 3.1 versus 8.1 (RR, 0.410; 95% CI, 0.180-0.933; P = .034), whereas recurrent injury rates per 100 player seasons were 7.1 versus 45.8 (RR, 0.137; 95% CI, 0.037-0.509; P = .003). Number needed to treat [NNT] to prevent 1 acute hamstring injury (new or recurrent) is 13 (95% CI, 9-23) players. The NNT to prevent 1 new injury is 25 (95% CI, 15-72) players, and NNT to prevent 1 recurrent injury is 3 (95% CI, 2-6) players. IN male professional and amateur soccer players, additional eccentric hamstring exercise decreased the rate of overall, new, and recurrent acute hamstring injuries.
Article
This prospective cohort study was conducted to identify risk factors for acute ankle injuries among male soccer players. A total of 508 players representing 31 amateur teams were tested during the 2004 pre-season through a questionnaire on previous injury and function score (foot and ankle outcome score; FAOS), functional tests (balance tests on the floor and a balance mat) and a clinical examination of the ankle. Generalized estimating equations were used in univariate analyses to identify candidate risk factors, and factors with a P-value <0.10 were then examined in a multivariate model. During the season, 56 acute ankle injuries, affecting 46 legs (43 players), were registered. Univariate analyses identified a history of previous acute ankle injuries [odds ratio (OR) per previous injury: 1.25, 95% confidence interval (CI) 1.09-1.43] and the FAOS sub-score "Pain" (OR for a 10-point difference in score: 0.81, 95% CI 0.62-1.04) as candidate risk factors. In a multivariate analysis, only the number of previous acute ankle injuries proved to be a significant (adjusted OR per previous injury: 1.23; 95% CI 1.06-1.41, P=0.005) predictor of new injuries. Function scores, functional tests and clinical examination could not independently identify players at an increased risk in this study.
Article
All 12 female football clubs (228 players) and 11 of 14 male clubs (239 players) in the Swedish premier league were followed prospectively during the 2005 season. Individual exposure (playing time), injuries (time loss), and injury severity (days lost due to injury) were recorded by the team medical staffs. Injury incidence was higher for male players during both training (4.7 vs 3.8 injuries/1000 h, P=0.018) and match play (28.1 vs 16.1, P<0.001). However, no difference was found in the incidence of severe injury (absence >4 weeks) (0.7/1000 h in both groups). The thigh, especially the hamstrings, was the overall most commonly injured region in both sexes, while the hip/groin was more commonly injured in male players and the knee in female players. Knee ligament injuries accounted for 31% and 37% of the total time lost from football for male and female players, respectively. In conclusion, male elite players had a higher injury incidence than their female counterparts although no difference was observed in the incidence of moderate to severe injury. We recommend that preventive measures should be focused on hamstring and knee ligament injury in order to reduce the overall injury burden.
Article
Soccer has rapidly gained in interest in the United States. A paucity of available data on soccer injuries led us to formulate this study to quantitate and categorize injuries acquired during a program of youth soccer (under age 19). A prospective study of 1,272 players showed an injury rate of 2.6 injuries per 100 participants. The injury rate for girls was twice as great as for boys. The under 10-age group was seldom injured (less than 1 injury per 100 participants), but the overall injury rate in the players of secondary school age was 7.7 injuries per 100 participants. Most injuries were not serious. Soccer appears to be a safe activitiy for adolescents and children.
Article
The purpose of this study was to describe the firing pattern of 11 hip and knee muscles during running. Thirty recreational runners volunteered to run at 3 different paces with indwelling electromyographic electrodes while being filmed at 100 frames per second. Results demonstrated that medial and lateral vasti muscles acted together for knee extension during terminal swing and loading response, possibly providing a patella stabilizing role. The vastus intermedius muscle functioned with the other vasti, plus eccentrically controlled knee flexion during swing phase. The rectus femoris muscle fired with the vastus intermedius muscle and assisted the iliacus muscle with hip flexion. The hamstrings fired primarily to eccentrically control hip flexion. The adductor magnus, tensor fascia lata, and gluteus maximus muscles afforded pelvic stabilization while assisting with hip flexion and extension. Forward propulsion was provided mainly by hip flexion and knee extension, which is contrary to the view that posterior calf muscles provide propulsion during toe off. Faster running paces lead to increased activity in the muscles. This may lead to more injuries, primarily in the muscles that were contracting eccentrically.
Article
This study evaluated the incidence, distribution and types of musculoskeletal injuries sustained by 95 track and field athletes in a 12 month period using a retrospective cohort design, and analysed selected training, anthropometric, menstrual and clinical biomechanical risk factors. Overall, 72 athletes sustained 130 injuries giving an athlete incidence rate of 76% and an injury exposure rate of 3.9 per 1000 training hours. The majority of injuries were overuse in nature and approximately one-third of all injuries were recurrent. The risk of injury was not influenced by gender or event group. The most common sites of injury were the leg (28%), thigh (22%) and knee (16%) with the most common diagnoses being stress fractures (21%) and hamstring strains (14%). Injury patterns varied between event groups with middle-distance and distance runners sustaining more overuse injuries, and sprinters, hurdlers, jumpers and multi event athletes more acute injuries (p < 0.05). Increasing age, greater overall flexibility and a greater prevalence of menstrual disturbances were associated with a greater likelihood of injury. The results of this study show that track and field athletes are at high risk for musculoskeletal injury and that it may be possible to identify those who are more likely to sustain an injury.
Article
To define the causes of injuries to players in English professional football during competition and training. Lost time injuries to professional and youth players were prospectively recorded by physiotherapists at four English League clubs over the period 1994 to 1997. Data recorded included information related to the injury, date and place of occurrence, type of activity, and extrinsic Playing factors. In all, 67% of all injuries occurred during competition. The overall injury frequency rate (IFR) was 8.5 injuries/1000 hours, with the IFR during competitions (27.7) being significantly (p < 0.01) higher than that during training (3.5). The IFRs for youth players were found to increase over the second half of the season, whereas they decreased for professional players. There were no significant differences in IFRs for professional and youth players during training. There were significantly (p < 0.01) injuries in competition in the 15 minute periods at the end of each half. Strains (41%), sprains (20%), and contusions (20%) represented the major types of injury. The thigh (23%), the ankle (17%), knee (14%), and lower leg (13%) represented the major locations of injury, with significantly (p < 0.01) more injuries to the dominant body side. Reinjury counted for 22% of all injuries. Only 12% of all injuries were caused by a breach of the rules of football, although player to player contact was involved in 41% of all injuries. The overall level of injury to professional footballers has been showed to be around 1000 times higher times higher than for industrial occupations generally regarded as high risk. The high level of muscle strains, in particular, indicates possible weakness in fitness training programmes and use of warming up and cooling down procedures by clubs and the need for benchmarking players' levels of fitness and performance. Increasing levels of injury to youth players as a season progresses emphasizes the importance of controlling the exposure of young players to high levels of competition.
Article
In this study, the incidence of football injuries and complaints as related to different age groups and skill levels was studied over the period of 1 year. All injuries and complaints as well as the amount of time players spent in training and games were recorded. All injured players were examined weekly by physicians, and all injuries were assessed according to the International Classification of Diseases (ICD-10), which describes them in terms of injury type and location, the treatment required, and the duration of subsequent performance limitations. A total of 264 players of different age groups and skill levels was observed for 1 year. Five hundred fifty-eight injuries were documented. Two hundred sixteen players had one or more injuries. Only 48 players (18%) had no injury. The average number of injuries per player per year was 2.1. Injuries were classified as mild (52%), moderate (33%), or severe (15%). Almost 50% of all injuries were contact injuries; half of all the contact injuries were associated with foul play. The majority of injuries were strains and sprains involving the ankle, knee, and lumbar spine. Nearly all players (91%) suffered from complaints related to football. Only 23 players reported no injuries and no complaints. Prevention programs, fair play, and continuing education in techniques and skills may reduce the incidence of injuries over time.
Article
To compare the effects of a 10-week training program with two different exercises -- traditional hamstring curl (HC) and Nordic hamstrings (NH), a partner exercise focusing the eccentric phase -- on muscle strength among male soccer players. Subjects were 21 well-trained players who were randomized to NH training (n = 11) or HC training (n = 10). The programs were similar, with a gradual increase in the number of repetitions from two sets of six reps to three sets of eight to 12 reps over 4 weeks, and then increasing load during the final 6 weeks of training. Strength was measured as maximal torque on a Cybex dynamometer before and after the training period. In the NH group, there was an 11% increase in eccentric hamstring torque measured at 60 degrees s(-1), as well as a 7% increase in isometric hamstring strength at 90 degrees, 60 degrees and 30 degrees of knee flexion. Since there was no effect on concentric quadriceps strength, there was a significant increase in the hamstrings:quadriceps ratio from 0.89 +/- 0.12 to 0.98 +/- 0.17 (11%) in the NH group. No changes were observed in the HC group. NH training for 10 weeks more effectively develops maximal eccentric hamstring strength in well-trained soccer players than a comparable program based on traditional HC.
Article
To conduct a detailed analysis of hamstring injuries sustained in English professional football over two competitive seasons. Club medical staff at 91 professional football clubs annotated player injuries over two seasons. A specific injury audit questionnaire was used together with a weekly form that documented each clubs' current injury status. Completed injury records for the two competitive seasons were obtained from 87% and 76% of the participating clubs respectively. Hamstring strains accounted for 12% of the total injuries over the two seasons with nearly half (53%) involving the biceps femoris. An average of five hamstring strains per club per season was observed. A total of 13 116 days and 2029 matches were missed because of hamstring strains, giving an average of 90 days and 15 matches missed per club per season. In 57% of cases, the injury occurred during running. Hamstring strains were most often observed during matches (62%) with an increase at the end of each half (p<0.01). Groups of players sustaining higher than expected rates of hamstring injury were Premiership (p<0.01) and outfield players (p<0.01), players of black ethnic origin (p<0.05), and players in the older age groups (p<0.01). Only 5% of hamstring strains underwent some form of diagnostic investigation. The reinjury rate for hamstring injury was 12%. Hamstring strains are common in football. In trying to reduce the number of initial and recurrent hamstring strains in football, prevention of initial injury is paramount. If injury does occur, the importance of differential diagnosis followed by the management of all causes of posterior thigh pain is emphasised. Clinical reasoning with treatment based on best available evidence is recommended.
Article
Variations in definitions and methodologies have created differences in the results and conclusions obtained from studies of football injuries; this has made inter-study comparisons difficult. An Injury Consensus Group was established under the auspices of FIFA Medical Assessment and Research Centre. Using a nominal group consensus model approach, a working document that identified the key issues related to definitions, methodology and implementation was discussed by members of the group during a 2-day meeting. Following this meeting, iterative draft statements were prepared and circulated to members of the group for comment before the final consensus statement was produced. Definitions of injury, recurrent injury, severity and training and match exposures in football together with criteria for classifying injuries in terms of location, type, diagnosis and causation are proposed. Proforma for recording players' baseline information, injuries and training and match exposures are presented. Recommendations are made on how the incidence of match and training injuries should be reported and a checklist of issues and information that should be included in published reports of studies of football injuries is presented. The definitions and methodology proposed in the consensus statement will ensure that consistent and comparable results will be obtained from studies of football injuries.
Article
The purpose was to test the effect of eccentric strength training and flexibility training on the incidence of hamstring strains in soccer. Hamstring strains and player exposure were registered prospectively during four consecutive soccer seasons (1999-2002) for 17-30 elite soccer teams from Iceland and Norway. The first two seasons were used as baseline, while intervention programs consisting of warm-up stretching, flexibility and/or eccentric strength training were introduced during the 2001 and 2002 seasons. During the intervention seasons, 48% of the teams selected to use the intervention programs. There was no difference in the incidence of hamstring strains between teams that used the flexibility training program and those who did not [relative risk (RR)=1.53, P=0.22], nor was there a difference compared with the baseline data (RR=0.89, P=0.75). The incidence of hamstring strains was lower in teams who used the eccentric training program compared with teams that did not use the program (RR=0.43, P=0.01), as well as compared with baseline data for the same intervention teams (RR=0.42, P=0.009). Eccentric strength training with Nordic hamstring lowers combined with warm-up stretching appears to reduce the risk of hamstring strains, while no effect was detected from flexibility training alone. These results should be verified in randomized clinical trials.
Article
Football is one of the leading causes of athletic-related injuries. Injury rates and patterns of the training camp period of the National Football League are unknown. Injury rates will vary with time, and injury patterns will differ between training camp practices and preseason games. Descriptive epidemiology study. From 1998 to 2007, injury data were collected from 1 National Football League team during its training camp period. Injuries were recorded as a strain, sprain, concussion, contusion, fracture/dislocation, or other injury. The injury was further categorized by location on the body. Injury rates were determined based on the exposure of an athlete to a game or practice event. An athlete exposure was defined as 1 athlete participating in 1 practice or game. The injury rate was calculated as the ratio of injuries per 1000 athlete exposures. There were 72.8 (range, 58-109) injuries per year during training camp. Injuries were more common during weeks 1 and 2 than during weeks 3 to 5. The rate of injury was significantly higher during games (64.7/1000 athlete exposures) than practices (12.7/1000 athlete exposures, P < .01). The rate of season-ending injuries was also much higher in games (5.4/1000 athlete exposures) than practices (0.4/1000 athlete exposures). The most common injury during the training camp period was a knee sprain, followed by hamstring strains and contusions. Muscle strains are the most common injury type in practices. Contact type injuries are most common during pre-season games, and the number of significant injuries that occur during preseason games is high.
Article
The relationship between muscle injury and strength disorders remains a matter of controversy. Professional soccer players performed a preseason isokinetic testing aimed at determining whether (1) strength variables could be predictors of subsequent hamstring strain and (2) normalization of strength imbalances could reduce the incidence of hamstring injury. Cohort study (prognosis); Level of evidence, 1. A standardized concentric and eccentric isokinetic assessment was used to identify soccer players with strength imbalances. Subjects were classified among 4 subsets according to the imbalance management content. Recording subsequent hamstring injuries allowed us to define injury frequencies and relative risks between groups. Of 687 players isokinetically tested in preseason, a complete follow-up was obtained in 462 players, for whom 35 hamstring injuries were recorded. The rate of muscle injury was significantly increased in subjects with untreated strength imbalances in comparison with players showing no imbalance in preseason (relative risk = 4.66; 95% confidence interval: 2.01-10.8). The risk of injury remained significantly higher in players with strength imbalances who had subsequent compensating training but no final isokinetic control test than in players without imbalances (relative risk = 2.89; 95% confidence interval: 1.00-8.32). Conversely, normalizing the isokinetic parameters reduced the risk factor for injury to that observed in players without imbalances (relative risk = 1.43; 95% confidence interval: 0.44-4.71). The outcomes showed that isokinetic intervention gives rise to the preseason detection of strength imbalances, a factor that increases the risk of hamstring injury. Restoring a normal strength profile decreases the muscle injury incidence.
A study of injuries of soccer player in school students
  • T Kawagoe
  • Y Yamamoto
  • Y Suga
Kawagoe T, Yamamoto Y, Suga Y. A study of injuries of soccer player in school students. The Hokkaido Journal of Physical Therapy 2002; 19: 102-104