Article

11+ Dance: A Neuromuscular Injury Prevention Exercise Program for Dancers

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Abstract

Epidemiological studies over the past decade indicate high injury prevalence in preprofessional ballet (76%) and professional contemporary and ballet dancers (60–69%). Injuries can have detrimental effects both for the dancers and the dance company. Most injuries are in the lower limb and re- ported as the gradual onset of overuse. Professional dance companies have reduced injury incidence and severity through the implementation of com- prehensive injury audit programs and proactive exercise prescription. Injury prevention research in dance is scarce, and there has been no intervention targeting dance injuries. This article describes the development of 11+ Dance, an injury prevention training program designed for dancers, based on current evidence and best practice on injury prevention in sports. It is a 25–30-minute neuromuscular- based training program focused on strength, balance, and jumping/landing technique, with special attention to ankle, knee, and hip alignment. The high prevalence of injuries reported in the different styles of dance suggests that implementation of an injury prevention program is both the plausible and ethical action to take for all levels of performance.

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... Although the importance of involving end-users in developing and evaluating injury prevention programs has been promoted [10,23,29,30], injury prevention training programs have frequently been developed by researchers with little [9,31] or no involvement of endusers [32][33][34]. One recent exception is Bruder et al. [22], who involved experts and end-users when developing a context-specific program for female Australian Football players. ...
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Regular participation in organized youth sports does not ensure adequate exposure to skill- and health-related fitness activities, and sport training without preparatory conditioning does not appear to reduce risk of injury in young athletes. Current trends indicate that widespread participation in organized youth sports is occurring at a younger age, especially in girls. Current public health recommendations developed to promote muscle strengthening and bone building activities for youth aged 6 yr and older, along with increased involvement in competitive sport activities at younger ages, has increased interest and concern from parents, clinicians, coaches, and teachers regarding the optimal age to encourage and integrate more specialized physical training into youth development programs. This review synthesizes the latest literature and expert opinion regarding when to initiate neuromuscular conditioning in youth and presents a how-to integrative training conceptual model that could maximize the potential health-related benefits for children by reducing sports-related injury risk and encouraging lifelong, regular physical activity.
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The aim of the present study was to assess the prevalence and types of injuries in 1336 young, non-professional female dancers (age 8-16 years) who participated in a descriptive mixed (cross-sectional/ longitudinal) cohort study. Previous and current injuries were diagnosed and later classified into seven major categories. Our results show that 569 (42.6%) of the dancers examined manifested an injury. Advanced age and increased exposure to dance yielded an equivalent increase in the prevalence of injured girls: from 1 of 10 girls in the 8-year-old age cohort (mean = 1.05 per 1000 h) to 1 of 3 girls in the 14-year-old age cohort (mean = 1.25 per 1000 h). Time elapsing between first and second injuries decreased with age. Among the youngest group of dancers (8-9 years) the most common injury was tendonitis (41%), while in adolescent dancers (14-16 years) knee injuries became the leading cause of complaints (33%). We conclude that young, non-professional dancers are at high risk of injury. Dancers who had been injured in the past were at higher risk for re-injury. Tendonitis in the foot or ankle joint was a common injury among the youngest dancers, while knee injuries were common among adolescent dancers. A routine screening of this dancer population by an expert in dance medicine will reduce the risk for an injury.
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Lateral ankle sprains are amongst the most common injuries incurred by athletes, with the high rate of reoccurrence after initial injury becoming of great concern. Chronic ankle instability (CAI) refers to the development of repetitive ankle sprains and persistent residual symptoms post-injury. Some of the initial symptoms that occur in acute sprains may persist for at least 6 months post-injury in the absence of recurrent sprains, despite the athlete having returned to full functional activity. CAI is generally thought to be caused by mechanical instability (MI) or functional instability (FI), or both. Although previously discussed as separate entities, recent research has demonstrated that deficits associated with both MI and FI may co-exist to result in CAI. For clinicians, the main deficits associated with CAI include deficits in proprioception, neuromuscular control, strength and postural control. Based on the literature reviewed, it does seem that subjects with CAI have a deficit in frontal plane ankle joint positional sense. Subjects with CAI do not appear to exhibit any increased latency in the peroneal muscles in response to an external perturbation. Preliminary data suggest that feed-forward neuromuscular control may be more important than feed-back neuromuscular control and interventions are now required to address deficits in feed-forward neuromuscular control. Balance training protocols have consistently been shown to improve postural stability in subjects with CAI. Subjects with CAI do not experience decreased peroneus longus strength, but instead may experience strength deficits in the ankle joint invertor muscles. These findings are of great clinical significance in terms of understanding the mechanisms and deficits associated with CAI. An appreciation of these is vital to allow clinicians to develop effective prevention and treatment programmes in relation to CAI.
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Do females with patellofemoral pain syndrome have decreased hip muscle strength compared with the unaffected side and with healthy controls? A systematic review of observational studies published up to January 2008. Females with patellofemoral pain syndrome and healthy controls. Strength for at least one hip muscle group had to be included in the study. Hip muscle strength was recorded as force or torque. Five cross-sectional studies with a mean Newcastle-Ottawa Assessment Scale score of 6 out of 9 met the inclusion criteria. Strong evidence was found for a deficit in hip external rotation, abduction and extension strength, moderate evidence for a deficit in hip flexion and internal rotation strength, and no evidence for a deficit in hip adduction strength compared with healthy controls. Moderate evidence was found for a decrease in hip external rotation and abduction strength but no evidence for a decrease in hip extension, flexion, adduction and internal rotation strength compared with the unaffected side. Females with patellofemoral pain syndrome demonstrate a decrease in abduction, external rotation and extension strength of the affected side compared with healthy controls.
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Cross-sectional. To determine if females with anterior knee pain are more likely to demonstrate hip abduction or external rotation weakness than a similar, asymptomatic, age-matched control group. Diminished hip strength has been implicated as being contributory to lower-extremity malalignment and patellofemoral pain. The identification of reliable and consistent patterns of weakness in this population may assist health care professionals establish a more effective treatment plan. Hip abduction and external rotation isometric strength measurements were recorded for the injured side of 15 female subjects with patellofemoral joint pain (mean +/- SD age, 15.7 +/- 2.7 years; age range, 12-21 years). These were compared with strength measurements from the corresponding hip of 15 age-matched female control subjects (mean +/- SD age, 15.7 +/- 2.7 years; age range, 12-21 years). All strength measurements were made using hand-held dynamometers. Subjects with patellofemoral pain demonstrated 26% less hip abduction strength (P<.001) and 36% less hip external rotation strength (P<.001) than similar age-matched controls. The results indicate that young women with patellofemoral pain are more likely to demonstrate weakness in hip abduction as well as external rotation than age-matched women who are not symptomatic.
Article
Objectives To describe the incidence rate, severity, burden and aetiology of medical attention and time-loss injuries across five consecutive seasons at a professional ballet company. Methods Medical attention injuries, time-loss injuries and dance exposure hours of 123 professional ballet dancers (women: n=66, age: 28.0±8.3 years; men: n=57, age: 27.9±8.5 years) were prospectively recorded between the 2015/2016 and 2019/2020 seasons. Results The incidence rate (per 1000 hours) of medical attention injury was 3.9 (95% CI 3.3 to 4.4) for women and 3.1 (95% CI 2.6 to 3.5) for men. The incidence rate (per 1000 hours) of time-loss injury was 1.2 (95% CI 1.0 to 1.5) for women and 1.1 (95% CI 0.9 to 1.3) for men. First Soloists and Principals experienced between 2.0–2.2 additional medical attention injuries per 1000 hours and 0.9–1.1 additional time-loss injuries per 1000 hours compared with Apprentices (p≤0.025). Further, intraseason differences were observed in medical attention, but not time-loss, injury incidence rates with the highest incidence rates in early (August and September) and late (June) season months. Thirty-five per cent of time-loss injuries resulted in over 28 days of modified dance training. A greater percentage of time-loss injuries were classified as overuse (women: 50%; men: 51%) compared with traumatic (women: 40%; men: 41%). Conclusion This is the first study to report the incidence rate of medical attention and time-loss injuries in professional ballet dancers. Incidence rates differed across company ranks and months, which may inform targeted injury prevention strategies.
Article
Context There is no evidence regarding the effect of the FIFA 11+ on landing kinematics in male soccer players and also few studies exist regarding the evaluating progress of interventions based on the initial biomechanical profile. Objective The aim of this study was to investigate the effect of the FIFA 11+ program on landing patterns in soccer players classified as at low or high risk for non-contact anterior cruciate ligament (ACL) injuries. Design Randomized controlled trial. Setting Field-based functional movement screening performed at the soccer field. Participants Twenty-four elite male youth soccer players participated in this study. Intervention The intervention group performed the FIFA 11+ program 3 times per week for 8 weeks, whereas the control group performed their regular warm-up program. Main Outcome Measures Before and after the intervention, all participants were assessed for landing mechanics using the landing error scoring system (LESS). Pre-training LESS scores were used to determine risk groups. Results The FIFA 11+ group had greater improvement than the control group in terms of improving the landing pattern; there was a significant intergroup difference (F (1, 20) = 28.86, P < .001, Partial η ² = .591). Soccer players categorized as being at high risk displayed greater improvement from the FIFA 11+ program than those at low risk ( P = .031). However, there was no significant difference in the proportion of risk category following the routine warm-up program ( P = 1.000). Conclusions The present study provides evidence of the usefulness of the FIFA 11+ program for reducing risk factors associated with non-contact ACL injuries. Our results also suggest that soccer players with the higher risk profile would benefit more than those with lower risk profiles and that targeting them may improve the efficacy of the FIFA 11+ program.
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Objective To identify which exercise combinations are most effective as part of a lower extremity injury prevention programme for team-sport athletes. Design Umbrella review. Data sources A comprehensive literature search was performed in PubMed, Scopus, Cochrane Library and PEDro databases. Studies published between January 2000 and March 2017 were included in this umbrella review. Study eligibility criteria Moderate to high-quality systematic reviews that investigated the effectiveness of a combination of two or more exercise components, that is, strength, agility, plyometrics, balance, stretching, technique, warm-up and functional activity, regarding injury incidence/rate of lower extremity injuries in team-sport athletes. The methodological quality of the included systematic reviews was independently assessed by two reviewers using the Assessing the Methodological Quality of Systematic Reviews measurement tool and the Grading of Recommendations Assessment, Development and Evaluation guidelines were used to assess the overall quality of evidence for particular outcomes. Results Twenty-four systematic reviews met the inclusion criteria. Multicomponent exercise interventions were effective in reducing the injury incidence/rate of lower extremity, knee, ACL and ankle injuries, but not groin injuries. Strength and balance exercise components were included in 10 of 11 effective injury prevention programmes for the lower extremity, knee, ACL and ankle injuries. Summary/conclusion Lower extremity injury prevention programmes in team sports are effective in preventing lower extremity, knee, ACL and ankle injuries. Lower extremity muscle strength and balance exercises should be prioritised in lower extremity injury prevention programmes for team-sport athletes.
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We analysed work-related musculoskeletal injuries (WMSI) in two modern dance companies to determine whether injury rates decreased and patterns altered compared to previous 3-yr and 6-yr audits (0.48 and 0.25/1000-hrs exposure respectively). In this prospectively designed 15-yr cohort study, data were collected in 30-dancer Company-1 and 12-dancer Company-2. In-house physical therapists tracked WMSI and time-loss-injuries for 159 dancers (42 dancers/yr). 15-yrs were grouped into five 3-yr blocks for comparison with prior audits. Negative binomial logistic regression analyses were conducted with exposure-hrs converted to the natural log and used as the offset variable. Block and company were categorical predictors for dependent variables: WMSI, time-loss-injuries, trauma-injuries and overuse-injuries (p < 0.05). 69% of dancers reported WMSI; 45% sustained at least one time-loss-injury. Company-1, with greater annual exposure, was 1.6-times more likely to sustain time-loss-injuries (p = 0.016, CI = 1.095–2.422) and 5.6-times more likely to sustain time-loss overuse-injuries (p = 0.003, CI = 1.812–17.327). Compared to Block-1, WMSI and time-loss-injuries decreased in Blocks-2, 3, and 5 (p ≤ 0.027). The ratio of time-loss overuse to trauma-injuries was reversed, with trauma-injuries accounting for over 80% of injuries by Block 5. Time-loss-injuries averaged 0.16 injuries/1000-hrs, lower than rates in ballet and sports. Decreased injury rates and changed injury patterns demonstrate efficacious injury management and prevention programming.
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Explanation of how goal-directed movements are made manifest is the ultimate aim of the field classically referred to as "motor control". Essential to the sought-after explanation is comprehension of the supporting functional architecture. Seven decades ago, the Russian physiologist and movement scientist Nikolai A. Bernstein proposed a hierarchical model to explain the construction of movements. In his model, the levels of the hierarchy share a common language (i.e., they are commensurate) and perform complementing functions to bring about dexterous movements. The science of the control and coordination of movement in the phylum Craniata has made considerable progress in the intervening seven decades. The contemporary body of knowledge about each of Bernstein's hypothesized functional levels is both more detailed and more sophisticated. A natural consequence of this progress, however, is the relatively independent theoretical development of a given level from the other levels. In this essay, we revisit each level of Bernstein's hierarchy from the joint perspectives of (a) the ecological approach to perception-action and (b) dynamical systems theory. We review a substantial and relevant body of literature produced in different areas of study that are accommodated by this ecological-dynamical version of Bernstein's levels. Implications for the control and coordination of movement and the challenges to producing a unified theory are discussed.
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Ankle inversion sprains are the most frequent acute musculoskeletal injuries occurring in physical activity. Interventions that retrain muscle coordination have helped rehabilitate injured ankles, but it is unclear which muscle coordination strategies, if any, can prevent ankle sprains. The purpose of this study was to determine whether coordinated activity of the ankle muscles could prevent excessive ankle inversion during a simulated landing on a 30-degree incline. We used a set of musculoskeletal simulations to evaluate the efficacy of two strategies for coordinating the ankle evertor and invertor muscles during simulated landing scenarios: planned co-activation and stretch reflex activation with physiologic latency (60-millisecond delay). A full-body musculoskeletal model of landing was used to generate simulations of a subject dropping onto an inclined surface with each coordination condition. Within each condition, the intensity of evertor and invertor co-activity or stretch reflexes were varied systematically. The simulations revealed that strong preparatory co-activation of the ankle evertors and invertors prior to ground contact prevented ankle inversion from exceeding injury thresholds by rapidly generating eversion moments after initial contact. Conversely, stretch reflexes were too slow to generate eversion moments before the simulations reached the threshold for inversion injury. These results suggest that training interventions to protect the ankle should focus on stiffening the ankle with muscle co-activation prior to landing. The musculoskeletal models, controllers, software, and simulation results are freely available online at , enabling others to reproduce the results and explore new injury scenarios and interventions.
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PART I OF THIS REVIEW DESCRIBES THE MOST IMPORTANT NEUROMUSCULAR SPORTS INJURY RISK FACTORS IN YOUTH ATHLETES: MUSCLE FATIGUE, ALTERED TIMING AND MAGNITUDE OF MUSCLE ACTIVATION, STRENGTH DEFICITS, PREDOMINANCE OF FRONTAL PLANE CONTROL STRATEGIES, NEUROMUSCULAR IMBALANCES BETWEEN LIMBS, INADEQUATE MUSCLE STIFFNESS, DEFICITS IN POSTURAL STABILITY, ALTERED PROPRIOCEPTION, AND FEED-FORWARD CONTROL. THE SECOND PART OF THIS REVIEW PROVIDES A FLEXIBLE APPROACH TO INTEGRATIVE NEUROMUSCULAR TRAINING WITH THE GOAL TO IMPROVE INJURY RESILIENCE AND TO ENHANCE SPORT AND MOTOR SKILL PERFORMANCE.
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Motor control is a relatively young field of research exploring how the nervous system produces purposeful, coordinated movements in its interaction with the body and the environment through conscious and unsconscious thought. Many books purporting to cover motor control have veered off course to examine biomechanics and physiology rather than actual control, leaving a gap in the literature. This book covers all the major perspectives in motor control, with a balanced approach. There are chapters explicitly dedicated to control theory, to dynamical systems, to biomechanics, to different behaviors, and to motor learning, including case studies. Reviews current research in motor control Contains balanced perspective between neuroscience, psychology, physics and biomechanicsHighlights controversies in the fieldDiscusses neurophysiology, control theory, biomechanics, and dynamical systems under one coverLinks principles of motor control to everyday behaviors Includes case studies delving into topics in more detail.
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The epidemiology of dance injuries requires further study, in order to properly implement effective health interventions. This study aimed to pilot injury surveillance tools to assess the incidence of injuries in adolescent pre-professional dancers and identify the intrinsic and extrinsic risk factors associated with dance injuries. The study involved a prospective, cohort design. A population of adolescent dancers at a liberal arts high school dance program in Natick, Massachusetts, was studied over the nine-month school year in 2000/2001. Intrinsic risk factors, including anatomical characteristics, past medical history, menstrual history, and dance experience, were assessed with a pre-participation history and orthopedic physical exam. The extrinsic risk factors, including training, fatigue, stress, shoes, and calcium intake, were assessed with surveys completed every two weeks by the dancers. Study outcomes were: 1) self-reported injuries (SRIs), 2) reported injuries (RIs) assessed by a physical therapist in the school clinic, 3) duration of injuries, and 4) severity of injuries. Descriptive statistics and univariate analyses were performed on each risk factor. Thirty-nine of 55 dancers participated in the study. The average age was 15.3 years, and 85% of the dancers were female. The return rate for the biweekly surveys was 90%. Over one school year, there were 112 self-reported injuries, averaging 2.8 SRIs per dancer, and 71 reported injuries assessed by the physical therapist, averaging 1.4 RIs per dancer. Consistent with other studies, the most common locations for injuries were ankles, lower leg/calf, and back, usually caused by overuse, muscle strains, and sprains. Although the female dancers reported dancing significantly more hours (3.3 hours per day) than the males (2.7 hours/day), the males had a higher injury rate of SRIs (8.4 injuries/1,000 exposure hours of dancing vs. 4.1 injuries/1,000 hours) as well as RIs (5.5 injuries/1,000 hours vs. 2.6 injuries/1,000 hours). Older age and male sex were risk factors associated with SRIs and RIs. Most risk factors were found not to be statistically associated with the number of SRIs or RIs. Self-reported injuries occur frequently in pre-professional student dancers, who seek medical care in more than half the cases. Health professionals involved with dancers should be familiar with posterior ankle and low back problems. The rates of injuries appear almost twice as high in male dancers than female dancers. The main limitations to this study were small sample size and misclassification, recall, and reporting biases. With the information and tools of this pilot study, a multi-center study can be carried out to better assess risk factors on a larger dance population. Further research should aim to standardize injury definitions and classifications.
Article
This study was undertaken to investigate whether differences exist in the coupling of foot and knee motions during the support phase of running in subjects with normal rearfoot motion and those who pronate. Excursion ratios between rearfoot eversion and tibial internal rotation were compared between the two groups. Timing between peak eversion, knee flexion, and knee internal rotation was also examined, and correlations between various foot and knee angles were assessed. Timings between peak knee and rearfoot angles were not significantly different between groups, although times were more closely matched in the normal subjects. The eversion to tibial internal rotation excursion ratio was significantly lower in the pronator subjects. Correlation analyses revealed significant relationships between a number of rearfoot and knee parameters. Results suggest that increased motion of the rearfoot can lead to excessive movement at the knee. In addition, excessive pronation may disrupt the normal kinematic interaction between the rearfoot and knee.
Article
The objective of this study was to review the evidence for selected risk factors of lower extremity overuse injuries in young elite female ballet dancers. An electronic search of key databases from 1969 to July 2013 was conducted using the keywords dancers, ballet dancers, athletes, adolescent, adolescence, young, injury, injuries, risk, overuse, lower limb, lower extremity, lower extremities, growth, maturation, menarche, alignment, and biomechanics. Thirteen published studies were retained for review. Results indicated that there is a high incidence of lower extremity overuse injuries in the target population. Primary risk factors identified included maturation, growth, and poor lower extremity alignment. Strong evidence from well-designed studies indicates that young elite female ballet dancers suffer from delayed onset of growth, maturation, menarche, and menstrual irregularities. However, there is little evidence that this deficit increases the risk of overuse injury, with the exception of stress fractures. Similarly, there is minimal evidence linking poor lower extremity alignment to increased risk of overuse injury. It is concluded that further prospective, longitudinal studies are required to clarify the relationship between growth, maturation, menarche, and lower extremity alignment, and the risk of lower extremity overuse injury in young elite female ballet dancers.
Article
Although dancing requires extensive physical exertion, dancers do not often train their physical fitness outside dance classes. Reduced aerobic capacity, lower muscle strength and altered motor control have been suggested as contributing factors for musculoskeletal injuries in dancers. This randomized controlled trial examined whether an intervention program improves aerobic capacity and explosive strength and reduces musculoskeletal injuries in dancers. Forty-four dancers were randomly allocated to a 4-month conditioning (i.e. endurance, strength and motor control training) or health promotion program (educational sessions). Outcome assessment was conducted by blinded assessors. When accounting for differences at baseline, no significant differences were observed between the groups following the intervention, except for the subscale “Pain” of the Short Form 36 Questionnaire (p=0.03). Injury incidence rate and the proportion of injured dancers were identical in both groups, but dancers following the conditioning program had significant less low back injuries (p=0.02). Supplementing regular dance training with a 4-month conditioning program does not lead to a significant increase in aerobic capacity or explosive strength in pre-professional dancers compared to a health promotion program without conditioning training, but leads to less reported pain. Further research should explore how additional training may be organized, taking into account the demanding dance schedule of pre-professional dancers. The trial is registered at ClinicalTrials.gov, number NCT01440153.
Article
Objective: The aim of this study was to determine whether an intervention with individualized conditioning program based on injury history and functional movement screening would be effective in reducing ballet injury incidence. Design: Prospective 3-year epidemiological study. Setting: Professional ballet company and its in-house medical facility. Participants: Dancers from a professional ballet company over the 3-year study period. Participant numbers ranged from 52 to 58 (year 1: 52; year 2: 58; year 3: 53). Interventions: The intervention consisted of individual conditioning programs developed using injury history and functional movement screening. Analysis was undertaken of the all dancers who were present in the company during the study period. The significance of change in injuries over a 3-year period was determined using a Poisson distribution model. Main outcomes measures: To determine whether individual conditioning programs resulted in a decrease in injury incidence over the study period. Results: The injury count reduced significantly in years 2 and 3 (P < 0.001). Injury incidence for male dancers declined from year 1 (in year/1000 h) (4.76/1000 h) to year 2 (2.40/1000 h) and year 3 (2.22/1000 h). For women, a reduction in the injury incidence was observed from year 1 (4.14/1000 h) to year 2 (1.71/1000 h) and year 3 (1.81/1000 h). Conclusions: Through prospective injury surveillance, we were able to demonstrate the benefit of individualized conditioning programs based on injury history and functional movement screening in reducing injuries in ballet. Clinical relevance: The implementation of well-structured injury surveillance programs can impact on injury incidence through its influence on intervention programs.
Article
HEWETT, T.E. and G.D. MYER. The mechanistic connection between the trunk, hip, knee, and anterior cruciate ligament injury. Exerc. Sport Sci. Rev., Vol. 39, No. 4, pp. 161-166, 2011. Neuromuscular control of the trunk and knee predicts anterior cruciate ligament injury risk with high sensitivity and specificity. These predictors are linked, as lateral trunk positioning creates high knee abduction torque (load). The hypotheses explored are that lateral trunk motion increases load and that neuromuscular training that enhance trunk control will decrease load.
Article
Contemporary clinical expertise and emerging research in anterior knee pain indicate that treatment of hip muscle function will result in greater effects, if such treatments can be provided to those with hip muscle dysfunction. Thus, it is imperative to develop and evaluate a clinical assessment tool that is capable of identifying people with poor hip muscle function. The clinical assessment of single-leg squat performance will have acceptable inter- and intrarater reliability. Furthermore, people with good performance on the single-leg squat will have better hip muscle function (earlier onset of gluteus medius activity and greater lateral trunk, hip abduction, and external rotation strength) than people with poor performance. Cohort study (diagnosis); Level of evidence, 2. A consensus panel of 5 experienced clinicians developed criteria to rate the performance of a single-leg squat task as "good," "fair," or "poor." The panel rated the performance of 34 asymptomatic participants (mean ± SD: age, 24 ± 5 y; height, 1.69 ± 0.10 m; weight, 65.0 ± 10.7 kg), and these ratings served as the standard. The ratings of 3 different clinicians were compared with those of the consensus panel ratings (interrater reliability) and to their own rating on 2 occasions (intrarater reliability). For the participants rated as good performers (n = 9) and poor performers (n = 12), hip muscle strength (hip abduction, external rotation, and trunk side bridge) and onset timing of anterior (AGM) and posterior gluteus medius (PGM) electromyographic activity were compared. Concurrency with the consensus panel was excellent to substantial for the 3 raters (agreement 87%-73%; κ = 0.800-0.600). Similarly, intrarater agreement was excellent to substantial (agreement 87%-73%; κ = 0.800-0.613). Participants rated as good performers had significantly earlier onset timing of AGM (mean difference, -152; 95% confidence interval [CI], -258 to -48 ms) and PGM (mean difference, -115; 95% CI, -227 to -3 ms) electromyographic activity than those who were rated as poor performers. The good performers also exhibited greater hip abduction torque (mean difference, 0.47; 95% CI, 0.10-0.83 N·m·Bw(-1)) and trunk side flexion force (mean difference, 1.08; 95% CI, 0.25-1.91 N·Bw(-1)). There was no difference in hip external rotation torque (P > .05) between the 2 groups. Targeted treatments, although considered ideal, rely on the capacity to identify subgroups of people with chronic anterior knee pain who might respond optimally to a given treatment component. Clinical assessment of performance on the single-leg squat task is a reliable tool that may be used to identify people with hip muscle dysfunction.
Article
The aim of this systematic review was to assess the effectiveness of proprioceptive/neuromuscular training in preventing sports injuries by using the best available evidence from methodologically well-conducted randomized controlled trials and controlled clinical trials without randomization. Two independent researchers performed a literature search in various electronic databases and reference lists. The reviewers independently assessed trials for inclusion criteria and methodological quality and extracted the data. Focusing on studies of high methodological quality, relative risks (RR) and 95% confidence intervals (CI) were used to estimate treatment effects. From a total of 32 relevant studies, 7 methodologically well-conducted studies were considered for this review. Pooled analysis revealed that multi-intervention training was effective in reducing the risk of lower limb injuries (RR = 0.61, 95% CI = 0.49-0.77, P < 0.01), acute knee injuries (RR = 0.46, 95% CI = 0.28-0.76, P < 0.01), and ankle sprain injuries (RR = 0.50, 95% CI = 0.31-0.79, P < 0.01). Balance training alone resulted in a significant risk reduction of ankle sprain injuries (RR = 0.64, 95% CI = 0.46-0.9, P < 0.01) and a nonsignificant risk reduction for injuries overall (RR = 0.49, 95% CI = 0.13-1.8, P = 0.28). Exercise interventions were more effective in athletes with a history of sports injury than in those without. On the basis of the results of seven high-quality studies, this review showed evidence for the effectiveness of proprioceptive/neuromuscular training in reducing the incidence of certain types of sports injuries among adolescent and young adult athletes during pivoting sports. Future research should focus on the conduct of comparative trials to identify the most appropriate and effective training components for preventing injuries in specific sports and populations.
Article
Sports injuries in young athletes are a public health issue which deserves special attention. Effective prevention can be achieved with training programmes originating from the field of physical therapy and medicine. A systematic literature search on injury prevention in youth sport was performed in the MEDLINE database. For prevention programmes to reduce sports injuries, critical factors must be considered, such as training content, duration and frequency, as well as athlete compliance. Home-based programmes could be inferior to supervised training, but are efficient if compliance is high. So far prevention programmes have focused on team sports and their efficiency in individual sports remains to be proven. Active prevention programmes focusing specifically on the upper extremity are scarce. Initiatives enhancing the awareness of trainers, athletes and therapists about risk factors and systematic prevention measures should be encouraged.
Article
The methodology for studies designed to investigate potential risk factors for sports injury is reviewed, using the case of hamstring strains as an example. Injuries result from a complex interaction of multiple risk factors and events. Therefore, a multivariate statistical approach should be used. In addition, the sample size of the study needs to be considered carefully. Sample size mainly depends on the expected effect of the risk factor on injury risk, and to detect moderate to strong associations 20-50 injury cases are needed, whereas small to moderate associations would need about 200 injured subjects. Studies published to date on the risk factors for hamstring strains have methodological limitations, and are too small to detect small to moderate associations.