Ballet injuries. An analysis of epidemiology and financial outcome

Exploring biomechanical variations in ankle joint injuries among Latin dancers with different stance patterns: utilizing OpenSim musculoskeletal models

Background: Dancers represent the primary demographic affected by ankle joint injuries. In certain movements, some Latin dancers prefer landing on the Forefoot (FT), while others prefer landing on the Entire foot (ET). Different stance patterns can have varying impacts on dancers' risk of ankle joint injuries. The purpose of this study is to investigate the differences in lower limb biomechanics between Forefoot (FT) dancers and Entire foot (ET) dancers. Method: A group of 21 FT dancers (mean age 23.50 (S.D. 1.12) years) was compared to a group of 21 ET dancers (mean age 23.33 (S.D. 0.94) years), performing the kicking movements of the Jive in response to the corresponding music. We import data collected from Vicon and force plates into OpenSim to establish musculoskeletal models for computing kinematics, dynamics, muscle forces, and muscle co-activation. Result: In the sagittal plane: ankle angle (0%-100%, p < 0.001), In the coronal plane: ankle angle (0%-9.83%, p = 0.001) (44.34%-79.52%, p = 0.003), (88.56%-100%, p = 0.037), ankle velocity (3.73%-11.65%, p = 0.017) (94.72-100%, p = 0.031); SPM analysis revealed that FT dancers exhibited significantly smaller muscle force than ET dancers around the ankle joint during the stance phase. Furthermore, FT dancers displayed reduced co-activation compared to ET dancers around the ankle joint during the descending phase, while demonstrating higher co-activation around the knee joint than ET dancers. Conclusion: This study biomechanically demonstrates that in various stance patterns within Latin dance, a reduction in lower limb stance area leads to weakened muscle strength and reduced co-activation around the ankle joint, and results in increased ankle inversion angles and velocities, thereby heightening the risk of ankle sprains. Nevertheless, the increased co-activation around the knee joint in FT dancers may be a compensatory response for reducing the lower limb stance area in order to maintain stability.

Musculoskeletal Injury in an Australian Professional Ballet Company, 2018-2021: 953 Medical-Attention and 706 Time-Loss Injuries Over 4 Years

OBJECTIVES: To describe the incidence rate, frequency, severity, recurrence, and burden of musculoskeletal injury in professional ballet. STUDY DESIGN: Descriptive epidemiological (retrospective). METHODS: Professional dancers (n = 73, 40 females, 33 males) provided consent for retrospective review of musculoskeletal injury data. Medical-attention injuries were reported to and recorded by onsite physiotherapists between January 2018 and December 2021. Time-loss injuries were any injury that prevented a dancer from taking a full part in all dance-related activities for >1 day. Injuries were classified using the OSICS-10.1 system. Injury incidence rates (IIRs; injuries/1000 h), severity, recurrence, and burden were calculated. RESULTS: Nine hundred and fifty-three medical-attention injuries were recorded in 72 (98%) dancers at an IIR of 2.79/1000 h (95% confidence interval [CI], 2.62-2.98). 706 were time-loss injuries, which were reported in 70 dancers at an IIR of 2.07/1000 h (95% CI: 1.92, 2.23). Overuse injuries represented 53% of medical-attention injuries. The most frequently injured body area and tissue/pathology were thoracic facet joint (n = 63/953, 7%) and ankle synovitis/impingement (n = 62/953, 6%). Bone stress injuries (BSIs) were the most severe with the highest median time loss (135 days, interquartile range [IQR] 181) followed by fractures (72.5 days, IQR 132). The injuries with the highest burden were tibial BSIs (13 days lost/1000 h; 95% CI: 13, 14). Jumping and lifting were the most frequently reported injury mechanisms. CONCLUSION: Almost all dancers required medical attention for at least one injury during the surveillance period. Approximately 74% of injuries resulted in time loss. BSIs and ankle synovitis/impingement were of high burden, and a high proportion of BSIs were recurrent. J Orthop Sports Phys Ther 2023;53(11):712-722. Epub 14 September 2023. doi:10.2519/jospt.2023.11858.

Epidemiological Characteristics of Foot and Ankle Injuries in 2 Professional Ballet Companies: A 3-Season Cohort Study of 588 Medical Attention Injuries and 255 Time-Loss Injuries

Background

The foot and ankle are often reported as the most common sites of injury in professional ballet dancers; however, epidemiological research focusing on foot and ankle injuries in isolation and investigating specific diagnoses is limited.

Purpose

To investigate the incidence rate, severity, burden, and mechanisms of foot and ankle injuries that (1) required visiting a medical team (medical attention foot and ankle injuries; MA-FAIs) and (2) prevented a dancer from fully participating in all dance-related activities for at least 24 hours after the injury (time-loss foot and ankle injuries; TL-FAIs) in 2 professional ballet companies.

Study Design

Descriptive epidemiological study.

Methods

Foot and ankle injury data across 3 seasons (2016-2017 to 2018-2019) were extracted from the medical databases of 2 professional ballet companies. Injury-incidence rate (per dancer-season), severity, and burden were calculated and reported with reference to the mechanism of injury.

Results

A total of 588 MA-FAIs and 255 TL-FAIs were observed across 455 dancer-seasons. The incidence rates of MA-FAIs and TL-FAIs were significantly higher in women (1.20 MA-FAIs and 0.55 TL-FAIs per dancer-season) than in men (0.83 MA-FAIs and 0.35 TL-FAIs per dancer-season) (MA-FAIs, P = .002; TL-FAIs, P = .008). The highest incidence rates for any specific injury pathology were ankle impingement syndrome and synovitis for MA-FAIs (women 0.27 and men 0.25 MA-FAIs per dancer-season) and ankle sprain for TL-FAIs (women 0.15 and men 0.08 TL-FAIs per dancer-season). Pointe work and jumping actions in women and jumping actions in men were the most common mechanisms of injury. The primary mechanism of injury of ankle sprains was jumping activities, but the primary mechanisms of ankle synovitis and impingement in women were related to dancing en pointe.

Conclusion

The results of this study highlight the importance of further investigation of injury prevention strategies targeting pointe work and jumping actions in ballet dancers. Further research for injury prevention and rehabilitation strategies targeting posterior ankle impingement syndromes and ankle sprains are warranted.

Relationship of Extrinsic Risk Factors to Lower Extremity Injury in Collegiate Ballet Dancers

Ballet dancers are thought to be at higher risk of lower extremity injury. This objective of this study was to describe the self-reported incidence, location, and factors associated with lower extremity injury in collegiate ballet dancers. Two hundred and forty-nine female ballet dancers responded to a questionnaire that addressed their injury event/location, dance behavior over the past 2 years, and overall dance history. Behaviors assessed included the following: types and number of shoes worn (pointé shoes/ballet slippers), wear time, training time (session frequency and duration), use of warm-up/cool-down, and use of a strengthening program and lower extremity accessory. Overall dance history included age of the onset of training, total years of experience, and number of dance styles. Backward multivariable logistic regression analysis was used to determine the extent to which variables measured were associated with injury. Ankle injury was the most prevalent injury. Years of wearing pointé shoes (adjusted odds ratio = 1.21, p = 0.01) and days/weeks in pointé shoes (adjusted odds ratio = 1.26, p = 0.04) were associated with an increased risk of injury; while additional strengthening (adjusted odds ratio = 0.39, p = 0.02) and use of lower extremity accessories during classes/rehearsals (adjusted odds ratio = 0.64, p = 0.01) were protective associations. These findings suggested that the use of pointé shoes, lower extremity accessories, and additional exercise should specifically be recorded during evaluation of injured ballet dancers; and must be considered potential factors to modify during rehabilitation.

Qualitative Analysis of Risk Factors and Foot and Ankle Injuries in Ballet Dancers

BACKGROUND

Ballet dancers are exposed to high rates of foot and ankle injury. Nevertheless, there have been limited efforts to capture their perspectives regarding risk of injury, treatment compliance, and prevention. The purpose of this study was to portray the perspectives of ballet dancers collected through organized focus group discussions.

METHODS

Seven focus group sessions were conducted, with 47 ballet dancers participating. The conversation was directed to consider a variety of factors related to injury, both direct and remote. Transcripts from these focus groups were coded into ten major themes: internal pressure, external pressure, ballet milestones, seeking treatment, treatment compliance, targeted treatment, return to dance, nondance activities, physical fatigue, and activity preparation.

RESULTS

It was found that participants returned to dancing prematurely after injury, faced significant internal and external pressure, lacked adherence to suggested treatment, and identified provider communication as lacking.

CONCLUSIONS

The results of this study can help with efforts to reduce injuries, encourage treatment compliance, and improve injury prevention. Future studies might consider the effectiveness of specific interventional approaches.

On-site Clinical Care for Professional Dance Companies

Thirty years ago the introduction of on-site health care for professional dance companies was a novel concept and dance medicine clinicians often had limited on-site hours, restricted treatment space, and small budgets. Companies are now developing fully staffed on-site clinics and backstage care that provide a multidisciplinary approach to dancer health and wellness. On-site dance medicine programs focus on holistic dancer health and preventive care rather than just triage and rehabilitation. Best practice recommendations for care of professional dancer patients allow for streamlined patient care within a network of medical professionals who understand the demands of a professional dance career.

Characteristic Poses in Ballet in the Case of a Retired Classical Ballerina after Bilateral THA: A Case Report and Review of Literature

Background

Ballet dance involves extreme range of motion (ROM) in the hip joint. This ROM can cause injuries including labral strain, tears, and subluxation episodes. Case Presentation. A 69-year-old female classical ballet dance instructor presented bilateral hip pain. The plain radiograph showed end-stage osteoarthritic change in the bilateral hip. She could neither dance nor perform daily activities. Bilateral hybrid total hip arthroplasty (THA) was performed. After surgery, she was able to demonstrate the split position on the floor as an active classical ballerina. The plain radiograph was taken in the split position, and the radiograph did not show any characteristics of impingement or subluxation of the femoral head.

Conclusion

She was able to continue working as a classical ballet instructor after bilateral THA. Additionally, any characteristics of impingement or subluxation of the femoral head were not revealed in the postoperative radiograph in the split position.

Injury epidemiology in professional ballet: a five-season prospective study of 1596 medical attention injuries and 543 time-loss injuries

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.

The Impact of Dance-Specific Neuromuscular Conditioning and Injury Prevention Training on Motor Control, Stability, Balance, Function and Injury in Professional Ballet Dancers: A Mixed-Methods Quasi-Experimental Study

BACKGROUND

Professional ballet dancers suffer high injury rates and are less likely than other athletes to specifically train to improve muscular strength, coordination, agility, speed and motor control because of heavy training demands, aesthetic appearances and financial barriers.

HYPOTHESIS/PURPOSE

The purpose of this study was to examine the effects of a supplemental conditioning program on professional and pre-professional contemporary ballet dancers. The authors hypothesized that those participating in a training program would reduce injury rate by improving their motor control, stability, balance and physical function. The authors aimed to observe the feasibility and qualitative phenomena related to a conditioning program from the dancer's perspective.

STUDY DESIGN

A mixed-methods study; within subject quasi-experimental design and qualitative interviews.

METHODS

Six professional classical and contemporary ballet dancers completed the five-week conditioning and injury prevention training program. Non-parametric analysis of baseline, posttest and four-month follow-up physical performance measures, subjective outcomes, and qualitative follow-up interviews, were reported.

RESULTS

Significant post-test improvements included: The Dance Functional Outcome Survey (Z= -2.2, p= 0.04), composite Modified Star Excursion Balance Test (Z= -2.2, p= 0.03 bilaterally), Single Leg Hop for Distance (Z= -2.02, p= 0.04), and Upper Extremity Closed Kinetic Chain Test (Z=-2.03, p= 0.04). Significant changes from baseline to the four-month follow up remained for: (1) Dance Functional Outcome Survey (Z= -2.2, p= 0.03), (2) Single Leg Hop for Distance (Z= -2.2, p= 0.03), and (3) Modified Star Excursion Balance Test composite maximum reach for the left lower extremity (Z= -2.2, p= 0.03).

CONCLUSION

Completing a conditioning and prevention program for professional ballet dancers was related to improved function, balance, hop distance/stability and upper extremity stability. Dancers found the program beneficial, identified barriers to participation, and elucidated factors making the program feasible and successful. More research is necessary to determine the effect of such programs on injury incidence.

LEVEL OF EVIDENCE

3b.

Rehabilitation of the Dancer

Rehabilitation of dance injury should be a team-based approach lead by a medical practitioner with experience in both musculoskeletal medicine and dance specific demands. The rehabilitation protocol begins with a dance specific initial assessment, followed by injury management, progression of the rehabilitation program including dance specific movement, advancing to full independence.

Access to Health Care Among Dancers

Dancers require a unique blend of artistry and athleticism, and have specific medical problems that require the expertise of health care professionals who understand the demands of the performing arts. There is often a lack of alignment between health care systems and dancers' perceptions of care. Factors including country of residence, socioeconomic status, and local infrastructure can affect dancers' access to health care. Efforts to improve access are evident, and specialized care for dancers has grown significantly in recent decades. By developing and refining systems of care delivery, there are opportunities to ensure optimal health of the dancer population.

LOW BACK PAIN AND INJURY IN BALLET, MODERN, AND HIP-HOP DANCERS: A SYSTEMATIC REVIEW

Background

Low back pain is believed to be a common complaint among dancers; however, a comparison across recent research is needed to support or disprove this assertion across genres.

Purpose

To determine the prevalence of low back pain and low back injury in ballet, modern, and hip-hop dancers through a systematic literature review. A secondary goal was to identify trends amongst dance genres, level of mastery, gender, and age, if possible.

Study Design

Systematic Review of the Literature.

Methods

PRISMA search strategy of terms relating to dance and low back pain was conducted within the Pubmed, MEDLINE, SPORTDiscus, Web of Science, and the archives of the Journal of Dance Medicine and Science databases between November 2017 and March 2018. Inclusion criteria were published articles that addressed low back pain or injury in ballet, modern, or hip-hop dance population. Exclusion criteria included studies relating to specific pathologies or studies that did not report specific dance genre. All included articles were assessed for quality using a modified grading evaluation and a Modified Newcastle-Ottawa Risk of Bias assessment.

Results

Twenty-five ballet articles, five modern, and three hip-hop articles met the inclusion criteria, for a total of 33 articles. Twenty-five of the 33 studies relied on a questionnaire to gather data. Risk of bias results ranged from 3-7/10 and quality of studies ranged from Good I to Limited III. Prevalence of low back pain seems relatively high in ballet dance (range: 20.3%-79% of total dancers are affected). Little research exists on the prevalence of back pain in modern or hip-hop dancers, but hip-hop dancers also seem likely to have low back pain (range: 46.6%-85.7% of total dancers are affected). Low back injuries are also present in ballet (range: 2.1%-88% of total injuries), modern (range: 8.6%-21.6% of total injuries), and hip-hop (range: 26.3%-69.6%).

Conclusion

Ballet dancers seem to be at risk for low back pain or injury independent of gender, age or level of mastery; however, there is not enough evidence to draw any conclusions about modern dancers or hip-hop dancers and their risk for low back pain/injury currently. Future higher-level studies are needed with reduced risk of bias.

Level of Evidence

2a.

Injuries during transition periods across the year in pre-professional and professional ballet and contemporary dancers: A systematic review and meta-analysis

OBJECTIVE

To consider the association of injuries with transition periods in the dance year, i.e., when dancers return at the start of the year, and when they transition from rehearsal to performance periods.

METHODS

Six electronic databases were searched to November 2019. All English language peer-reviewed studies, of any study design investigating ballet and contemporary pre-professional and professional dance populations were included. Only those studies reporting on the timing of injury were included.

RESULTS

Fifteen cohort and two case-series studies were included. A meta-analysis of seven studies revealed the rate of injuries to be significantly higher for the second and third months (1.52; 95% confidence interval [CI]:1.11-2.08; 1.26; 95%CI:1.07-1.48 respectively) after the return to dance. Two further studies report more injuries up to Week 13 of the year. One study showed an increase in injured dancers at three and four weeks after transition from rehearsals to a performance season. Four studies show an increase in injuries at performance times.

CONCLUSIONS

Meta-analyses of seven studies shows the second and third months after returning to dance have a significantly higher rate of injuries. More research is needed to quantify training loads in dance. Practitioners should be cognisant of the higher injury rates during periods of transition and consider modifying load, as it is a potential contributing factor.

Ankle Injuries in Dancers

The term dance encompasses a broad range of different styles; much of the orthopaedic literature has focused on ballet dancers. Injury is common in dancers at all levels, and many serious dancers sustain multiple injuries as they progress through their career. Foot and ankle injuries are among the most common injuries experienced by dancers. These injuries include those that are specific to dancers because of the unique physical maneuvers required to effectively perform, but they can also include common injuries that may require relatively different treatment because of the physical demands of the dancer. Os trigonum syndrome and flexor hallucis longus tenosynovitis generally fall into the former category as they are injuries that are more prevalent in dancers due to the extreme plantarflexion involved in dancing, especially ballet, and the relative demand placed on the toe flexors, most notably the flexor hallucis longus. On the other hand, anterior ankle impingement occurs both in dancers and in the general public. In many cases, a team approach to treatment with knowledgeable physical therapists can obviate the need for surgical treatment. If surgical treatment proves necessary, good results can be achieved with sound surgical technique and a well thought-out rehabilitation program.

The Epidemiology of Low Back Pain and Injury in Dance: A Systematic Review

BACKGROUND

Dance is a physical pursuit that involves loading the spine through repetitive dynamic movements and lifting tasks. As such, low back pain (LBP) and low back injury (LBI) have been identified as common health problems in contemporary and classical ballet dancers. However, clarity regarding the experience of LBP and LBI in dance is lacking.

OBJECTIVES

To systematically review and synthesize the epidemiology of LBP and LBI in dance populations.

METHODS

A comprehensive search of 6 electronic databases, back catalogs of dance science-specific journals, and reference lists of relevant articles and a forward citation search were performed.

RESULTS

Fifty full-text articles were included in the final systematic review. There was considerable methodological heterogeneity among the included studies. The median (range) point, yearly, and lifetime prevalence of LBP was 27% (17%-39%), 73% (41%-82%), and 50% (17%-88%), respectively. The lower back contributed to 11% (4%-22%) of time loss and 11% (5%-23%) of medical-attention injuries.

CONCLUSION

Dancers are vulnerable to LBP and LBI. The use of definitions that are sensitive to the complexity of LBP and LBI would facilitate improved understanding of the problem within dance, inform health care strategies, and allow for monitoring LBP-specific intervention outcomes. J Orthop Sports Phys Ther 2019;49(4):239-252. Epub 18 Jan 2019. doi:10.2519/jospt.2019.8609.

Foot and ankle joint movements of dancers and non-dancers: a comparative study

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint's contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p < 0.05). Although the ROMs were different between the two groups, the ratios of each joint movement were similar between these two groups, in all movements. Regarding total movement, the movement ratio of the talocrural joint was almost 70% and other joints accounted for almost 30% of the movement role in both dancers and non-dancers. Therefore, the differences in ROM between dancers and non-dancers were not a result of a specific joint movement but of all the relevant joints' collaborative movement.

Hip and Groin Injuries in Dancers: A Systematic Review

CONTEXT

Injury data on hip and groin injuries vary, and these injuries are often misrepresented or overlooked for more commonly seen injuries, such as those to the foot and ankle.

OBJECTIVE

To provide a systematic review of the injury rates of hip and groin pathology in dancers and look to establish a better understanding of the occurrence of hip and groin injuries in the dancer population.

DATA SOURCES

A literature search was performed using PubMed and CINAHL databases for articles published between 2000 and 2016.

STUDY SELECTION

Inclusion criteria consisted of (1) documentation of the number of hip and/or groin injuries, (2) study population consisting of dancers whose training included some level of ballet, and (3) studies of levels 1 through 3 evidence.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

A single reviewer identified studies that met the inclusion criteria. The number of overall injuries, hip/groin injuries, study participants, injured participants, training hours per week, mean age of study group, injury definition, injury reporting method, and study time frame were extracted.

RESULTS

Thirteen unique studies were included in the descriptive analysis. Of the 2001 dancers included in this study, 3527 musculoskeletal injuries were seen in 1553 dancers. Of these, 345 injuries were localized to the hip and groin region (overall rate, 17.2%). An incidence rate of 0.09 hip and groin injuries per 1000 dance-hours was seen in the selected cohort studies. Of 462 professional dancers, 128 hip/groin injuries were recorded, for an injury rate of 27.7%. Of the 1539 student dancers, 217 hip/groin injuries were recorded, for an injury rate of 14.1% ( P < 0.01).

CONCLUSION

Data on hip and groin injuries have many limitations. However, these injuries represent an important health issue for dancers of all skill levels, encompassing 17.2% of musculoskeletal injuries seen in dancers. An increasing rate of hip/groin injuries is seen in professional dancers compared with students.

Professional ballet dancers' experience of injury and osteopathic treatment in the UK: A qualitative study

OBJECTIVES

Professional dancers suffer significant musculoskeletal injuries during the course of their careers. Treatment-seeking behaviour is important in all patient populations, yet is rarely investigated amongst professional dancers. This qualitative study aimed to form a better understanding of how dancers decide to seek treatment, and in particular to explore their experiences of receiving osteopathic care for their injuries.

METHODS

A qualitative study design using grounded theory was used as a methodological framework for data collection and analysis. Semi-structured interviews were used to explore professional dancers' experience of injury and decision-making to seek professional healthcare.

RESULTS

Five themes were constructed that explain and describe dancers' experience of injuries and their views and perspectives of treatment, these were; the growing dancer, the fear factor, learning to cope, effective treatment, and returning autonomy.

CONCLUSION

The personal development of each dancer consisted of an amalgam of internal and external pressures. These pressures combine with experiences of pain and injury to influence a dancer's decision-making behaviour when injured and deciding to seek treatment. The study also provide factors relevant in the effective treatment of dancers, and outlined participants' preference for a global physical approach to assessment and treatment of their musculoskeletal pain.

Longitudinal study of sports injuries in practitioners of aerobic gymnastics competition

ABSTRACT Introduction: Aerobic gymnastics, since its membership in the International Gymnastics Federation, has undergone changes in its regulations. Objective: To analyze the injuries found in Spanish aerobic gymnastics athletes during different editions of the Code of Points. Methods: A descriptive, longitudinal and compara-tive study was carried out on the epidemiology of injuries in aerobic gymnastics published during different editions of the Code of Points. Results: It highlights that the number of injuries decreased from 156 to 38 last year. This decline has been related to the restriction on the number of difficulties in the exercise and the number of elements to be performed on the floor. However, they have increased the number and value of the difficulties. Conclusions: Therefore, it is concluded that the changes made in the regulations are intended to safeguard the health of athletes and ensure that competition develops at its best artistic and technical aspect.

Incidence and Prevalence of Musculoskeletal Injury in Ballet: A Systematic Review

BACKGROUND

Most published studies on injuries in the ballet dancer focus on the lower extremity. The rigors of this activity require special training and care. By understanding prevalence and injury pattern to the musculoskeletal system, targeted prevention and treatment for this population can be developed.

PURPOSE

To determine the incidence and prevalence of musculoskeletal injuries in ballet.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review registered with PROSPERO was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Level 1 through 4 evidence studies reporting incidence of musculoskeletal injuries in male and female ballet dancers were included, with the numbers and types of injuries extracted from each. Injury rates were recorded and calculated based on professional status, sex, and nature of injury. Incidence was defined as number of injuries sustained over a specific time. Prevalence was defined as proportion of subjects with an injury at a given point in time.

RESULTS

The studies analyzed reported injury incidence or prevalence in more than 1365 amateur and 900 professional dancers. The mean age was 16.2 years among amateur and 27.0 years among professional dancers. The incidence of injury among amateur dancers was 0.99 and 1.09 injuries per 1000 dance hours in males and females, respectively; 75% of injuries were overuse, with similar rates among males and females. In professional dancers, the incidence of injury was 1.06 and 1.46 injuries per 1000 dance hours in males and females, respectively, and 64% of female injuries were overuse, compared with 50% in males (P < .001). Only 3 studies provided prevalence data, including 62% prevalence of lumbosacral pain, 58% painful snapping hip, and 29% patellofemoral pain. Lower extremity injuries comprised 66% to 91% of all injuries, with the foot and ankle accounting for 14% to 57%.

CONCLUSION

The overall incidence of injury among amateur and professional ballet dancers is 0.97 and 1.24 injuries per 1000 dance hours, respectively. The majority are overuse in both amateur and professional dancers, with amateur ballet dancers showing a higher proportion of overuse injuries than professionals (P < .001). Male professional dancers show a higher proportion of traumatic injuries, accounting for half of their injuries (P < .001).

Comparison of landing biomechanics between male and female dancers and athletes, part 2: Influence of fatigue and implications for anterior cruciate ligament injury

BACKGROUND

Fatigue is strongly linked to an increased risk of injuries, including anterior cruciate ligament (ACL) ruptures. Part 1 of this study identified differences in the biomechanics of landing from a jump between dancers and team athletes, particularly female athletes, which may explain the epidemiological differences in ACL injuries between dancers and team athletes and the lack of a sex disparity within dancers. However, it is not known if these biomechanical variables change differently between team athletes and dancers in the face of fatigue. PURPOSE/ HYPOTHESIS: The purpose of this study was to compare dancers' and team athletes' resistance to fatigue and its effect on the biomechanics of single-legged drop landings. The primary hypotheses were that dancers may be more resistant than team athletes to the onset of fatigue and/or may have different biomechanical responses than athletes in landing tasks once fatigue has been achieved.

STUDY DESIGN

Controlled laboratory study.

METHODS

Kinematics and kinetics were recorded as 40 elite modern and ballet dancers (20 men and 20 women) and 40 team sport athletes (20 men and 20 women; National Collegiate Athletic Association Division I-III) performed single-legged drop landings from a 30-cm platform before and after a fatigue protocol consisting of step-ups and vertical jumps. Unfatigued and fatigued joint kinematics and kinetics were compared between groups and sexes with multivariate analyses of variance, followed by pairwise t tests as appropriate.

RESULTS

Dancers took longer (P = .023) than team athletes to reach a similar state of fatigue. Multiple kinetic (eg, increased peak knee valgus moment; P < .001) and kinematic (eg, increased lateral and forward trunk flexion; P < .001 and P = .002, respectively) parameters of landing changed with fatigue, such that both fatigued dancers and athletes landed with mechanics that were more at risk for ACL injuries as compared with before fatigue.

CONCLUSION

Dancers took significantly longer to reach fatigue than team athletes. Female athletes consistently exhibited landing patterns associated with a risk for ACL injuries when compared with the other 3 groups. Fatigue changed landing mechanics similarly in both dancers and athletes, such that all groups landed with worse alignment after being fatigued.

CLINICAL RELEVANCE

Dancers are more resistant to lower extremity fatigue than athletes, and this may partially explain the lower incidence of ACL injuries in both male and female dancers compared to team athletes. The extensive training in landing technique and daily practice that dancers undergo from a young age may be responsible for the higher levels of endurance.

Occupational accidents in professional dance with focus on gender differences

BACKGROUND

Classical dance comprises gender specific movement tasks. There is a lack of studies which investigate work related traumatic injuries in terms of gender specific differences in detail.

OBJECTIVE

To define gender related differences of occupational accidents.

METHODS

Basis for the evaluation were occupational injuries of professional dancers from three (n = 785; f: n = 358, m: n = 427) state theatres.

RESULTS

The incidence rate (0.36 per year) was higher in males (m: 0.45, f: 0.29). There were gender specific differences as to the localizations of injuries, particularly the spine region (m: 17.3%, f: 9.8%, p = 0.05) and ankle joint (m: 23.7%, f: 35.5%, p = 0.003). Compared to male dancers, females sustained more injuries resulting from extrinsic factors. Significant differences could specifically be observed with dance floors (m: 8.8%, f: 15.1%, p = 0.02). There were also significant gender differences observed with movement vocabulary.

CONCLUSION

The clearly defined gender specific movement activities in classical dance are reflected in occupational accidents sustained. Organisational structures as well as work environment represent a burden likewise to male and female dancers. The presented differences support the development of gender specific injury prevention measures.

Análise da incidência lesional na ginástica aeróbica espanhola de elite

INTRODUÇÃO: A ginástica aeróbica (GA) é uma disciplina que possui exigências físicas específicas e treinamento adequado para prevenir ou minimizar a ocorrência de lesões esportivas. OBJETIVO: Analisar a incidência de lesões na GA e a sua vinculação com fatores de treinamento MÉTODO: Realizou-se um estudo em 40 desportistas valencianos com idades compreendidas entre nove e 17 anos. O procedimento de coleta de informações foi através de um questionário de morbidade. A variável dependente foram as lesões durante a temporada 2009-2010 e as variáveis independentes principais foram a carga de treinamento, o material de proteção, superfície de treinamento, gesto técnico e tipo de lesão e zona corporal lesionada. RESULTADOS: As lesões mais reincidentes foram as relacionadas a ligamentos, afetando por igual os membros superior e inferior. A metade das lesões ocorreu após a realização dos saltos, apesar do uso de algum material de proteção, além de terem ocorrido no início da temporada. Relações significativas entre o número de lesões e a experiência, os dias de treinamento e o número de competições (p < 0,05) foram encontradas. CONCLUSÕES: O número de lesões diminuiu enquanto o uso de medidas de proteção, com destaque para as munhequeiras, aumentou. Metade das lesões produziu-se durante o período de aprendizagem técnica de dificuldades.

Preventing dance injuries: current perspectives

Dancers are clearly athletes in the degree to which sophisticated physical capacities are required to perform at a high level. The standard complement of athletic attributes - muscular strength and endurance, anaerobic and aerobic energy utilization, speed, agility, coordination, motor control, and psychological readiness - all are essential to dance performance. In dance, as in any athletic activity, injuries are prevalent. This paper presents the research background of dance injuries, characteristics that distinguish dance and dancers from traditional sports and athletes, and research-based perspectives into how dance injuries can be reduced or prevented, including the factors of physical training, nutrition and rest, flooring, dancing en pointe, and specialized health care access for dancers. The review concludes by offering five essential components for those involved with caring for dancers that, when properly applied, will assist them in decreasing the likelihood of dance-related injury and ensuring that dancers receive optimum attention from the health care profession: (1) screening; (2) physical training; (3) nutrition and rest; (4) specialized dance health care; and (5) becoming acquainted with the nature of dance and dancers.

Ballet injuries: injury incidence and severity over 1 year

STUDY DESIGN

Prospective, descriptive single-cohort study.

OBJECTIVE

To assess the incidence and severity of injuries to a professional ballet company over 1 year.

METHODS

Data for an elite-level ballet company of 52 professional dancers were collected by an in-house medical team using a time-loss injury definition.

RESULTS

A total of 355 injuries were recorded, with an overall injury incidence of 4.4 injuries per 1000 hours (female, 4.1; male, 4.8; P>.05) and a mean of 6.8 injuries per dancer (female, 6.3; male, 7.3; P>.05). Mean injury severity was 7 days (female, 4; male, 9; P<.05). Most injuries were classified as overuse (64%; female, 68%; male, 60%; P>.05); mean severity of injury was 3 days for females and 9 days for males (P<.05). The percentage of traumatic injuries was 32% for females and 40% for males (P<.05); the corresponding severity was 6 and 10 days, respectively (P<.05).

CONCLUSION

The relatively high number of injuries reported and the resulting loss of dance time support the need to introduce interventions to reduce the risk of injury in professional dancers.J Orthop Sports Phys Ther 2012;42(9):781-790. Epub 19 July 2012. doi:10.2519/jospt.2012.3893.

Management of dancers with symptomatic accessory navicular: 2 case reports

STUDY DESIGN

Case report.

BACKGROUND

Symptomatic accessory navicular can be a source of pain and disability. The treatment considerations for accessory navicular in dancers may differ due to increased demands on the foot, the repetitive nature of the movements, and the specific footwear required. The purpose of this report is to describe the management (1 conservative and 1 postoperative) of 2 adolescent dancers with symptomatic accessory navicular.

CASE DESCRIPTIONS

Case 1 was an 11-year-old female who underwent surgical excision of a symptomatic accessory navicular. Case 2 was a 15-year-old female who, following a traumatic injury that caused pain judged to be related to her accessory navicular, was managed nonsurgically. Treatment included pain management, range-of-motion exercises, trunk and lower extremity strengthening, balance and proprioception training, orthoses, crosstraining, and a guided return-to-dance progression.

OUTCOMES

Both patients had improved pain, dance technique, strength, and patient-reported outcome scores that allowed a full return to dance.

DISCUSSION

The 2 dancers presented here had foot pain believed to be related to a symptomatic accessory navicular. In both cases, treatment targeted specific impairments to improve function and disability. The guided progression of activities was intended to facilitate a return to dance that protected healing tissues and prevented a recurrence of symptoms. Clinicians should be aware of the effect of a symptomatic accessory navicular in the young dancer and potentially effective nonsurgical treatment options for this condition.

Changes in biomechanics and muscle activation in injured ballet dancers during a jump-land task with turnout (Sissonne Fermée)

Large impact loading with abnormal muscle activity and motion patterns may contribute to lower extremity injuries in ballet dancers. Yet, few studies investigated the influence of injury on the ballet movement. The purpose of this study was to find the neuromuscular and biomechanical characteristics in dancers with and without ankle injury during a jump-landing Sissonne Fermée task. Twenty-two ballet dancers were recruited and divided into the injured group (n = 11) and the uninjured group (n = 11). They performed a ballet movement called "Sissonne Fermée" with reflective markers and electrodes attached to their lower extremities. Ground reaction force, joint kinematics, and muscle activity were measured. The injured dancers had greater peak ankle eversion but smaller hindfoot-to-tibial eversion angles. Also, the injured dancers had greater activity of the hamstring of the dominant leg and tibialis anterior of the non-dominant leg during the pre-landing phase. The injured dancers had greater tibialis anterior activity of the dominant leg but less muscle activity in the medial gastrocnemius of the non-dominant leg during the post-landing phase. The injured dancers had a greater co-contraction index in the non-dominant ankle and a lower loading rate. The higher co-contraction indices showed that the injured dancers required more muscle effort to control ankle stability. Furthermore, the injured dancers used a "load avoidance strategy" to protect themselves from re-injury. Neuromuscular control training of the ankle joint for ballet dancers to prevent injury is necessary.

Musculoskeletal injuries in young ballet dancers

PURPOSE

The aim of this study was to examine the incidence of musculoskeletal injuries, site and type of injury, and the most common injury diagnoses in young ballet dancers at the Royal Swedish Ballet School, a public school in Stockholm.

METHODS

This retrospective study of 476 students (297 girls and 179 boys) aged 10-21 years was based on medical records for the period August 1988 to June 1995. Data on diagnosis, site of injury and type of injury were collected, and the injuries were classified as traumatic or due to overuse.

RESULTS

In total, 438 injuries were recorded. The injury incidence rate was 0.8 per 1,000 dance hours in both female and male dancers and tended to increase with increasing age. Most injuries occurred as the result of overuse. Seventy-six per cent of all injuries occurred in the lower extremities. Ankle sprain was the most common traumatic diagnosis, while the most common overuse-related diagnosis was tendinosis pedis. A few gender differences were noted.

CONCLUSIONS

The findings of this study suggest that there is a need to apply primary injury prevention in young ballet dancers. Future studies could aim to identify (1) injury risk factors and (2) injury prevention programmes that are effective at reducing injury rates in young dancers.

Outcomes of hip resurfacing in a professional dancer: a case report

A new surgical option (hip resurfacing arthroplasty) is now available for younger patients with hip osteoarthritis. A more aggressive rehabilitation program than the typical total hip arthroplasty protocol is needed for active individuals. This case report describes interventions used to maximize function in a 46-year-old professional dancer after hip resurfacing with a progressive therapeutic exercise program. Exercise choices were selected to address dance-specific requirements while respecting healing of the posterior capsular incision. Strengthening focused on hip abduction, extension, and external rotation. Precautions included avoiding gluteal stretching until 6 months. Pelvic alignment and weight-bearing distribution were emphasized. The patient was able to return to rehearsal by 7 months, at which time strength was equivalent to the unaffected leg. Range of motion reached unaffected side values at week 8 for internal rotation, week 11 for extension, week 13 for adduction, and week 28 for flexion. External rotation and abduction were still limited at 1 year, which influenced pelvic alignment with resultant pain on the unaffected side. Functional and impairment outcomes are presented with timelines to provide a basis for postoperative benchmarks for active clients after hip resurfacing. Although this case report presents a dance-specific program, exercise progressions for other active individuals may benefit from similar exercise intensity and sports-specific focus. Future rehabilitation programs should take into account possible flexion and external rotation range limitations and the need for gluteal muscle strengthening along with symmetry and pelvic alignment correction. Long-term studies investigating intensity of rehabilitation are warranted for patients intending to participate in higher level athletic activity.

Dancers with achilles tendinopathy demonstrate altered lower extremity takeoff kinematics

STUDY DESIGN

Controlled laboratory study using a cross-sectional design.

OBJECTIVES

To analyze lower extremity kinematics during takeoff of a "saut de chat" (leap) in dancers with and without a history of Achilles tendinopathy (AT). We hypothesized that dancers with AT would demonstrate different kinematic strategies compared to dancers without pathology, and that these differences would be prominent in the transverse and frontal planes.

BACKGROUND

AT is a common injury experienced by dancers. Dance leaps such as the saut de chat place a large demand on the Achilles tendon.

METHODS

Sixteen female dancers with and without a history of AT (mean ± SD age, 18.8 ± 1.2 years) participated. Three-dimensional kinematics at the hip, knee, and ankle were quantified for the takeoff of the saut de chat, using a motion analysis system. A force platform was used to determine braking and push-off phases of takeoff. Peak sagittal, frontal, and transverse plane joint positions during the braking and push-off phases of the takeoff were examined statistically. Independent samples t tests were used to evaluate group differences (α = .05).

RESULTS

The dancers in the tendinopathy group demonstrated significantly higher peak hip adduction during the braking phase of takeoff (mean ± SD, 13.5° ± 6.1° versus 7.7° ± 4.2°; P = .046). During the push-off phase, dancers with AT demonstrated significantly more internal rotation at the knee (13.2° ± 5.2° versus 6.9° ± 4.9°; P = .024).

CONCLUSION

Dancers with AT demonstrate increased peak transverse and frontal plane kinematics when performing the takeoff of a saut de chat. These larger displacements may be either causative or compensatory factors in the development of AT.

Is goniometry suitable for measuring ankle range of motion in female ballet dancers? An initial comparison with radiographic measurement

Female ballet dancers require extreme ankle motion to attain the demi-plié (weight-bearing full dorsiflexion [DF]) and en pointe (weight-bearing full plantar flexion [PF]) positions of ballet. However, techniques for assessing this amount of motion have not yet received sufficient scientific scrutiny. Therefore, the purpose of this study was to examine possible differences between weight-bearing goniometric and radiographic ankle range of motion measurements in female ballet dancers. Ankle range of motion in 8 experienced female ballet dancers was assessed by goniometry and 2 radiographic measurement methods. The latter were performed on 3 mediolateral x-rays, in demi-plié, neutral, and en pointe positions; one of them used the same landmarks as goniometry. DF values were not significantly different among the methods, but PF values were (P < .05). Not only was PF of the talocrural joint significantly less than the other 2 measurements (P < .001), PF from the goniometric method applied to the x-rays was significantly less than PF obtained from clinical goniometry (P < .05). These data provide insight into the extreme ankle and foot motion, particularly PF, required in female ballet dancers and suggest that goniometry may not be ideal for assessing ankle range of motion in these individuals. Therefore, further research is needed to standardize how DF and PF are measured in ballet dancers.

LEVEL OF EVIDENCE

Diagnostic, Level I.

Ankle and foot contributions to extreme plantar- and dorsiflexion in female ballet dancers

BACKGROUND

Female ballet dancers require extreme ankle motion. The objective of this study was to quantify the relative contributions of the ankle and various foot joints to extreme plantarflexion (PF) and dorsiflexion (DF) in female ballet dancers using an X-ray superimposition technique and digital graphics software.

MATERIALS AND METHODS

One asymptomatic ankle was studied in each of seven experienced female ballet dancers. Three lateral weightbearing X-rays were taken of each ballet dancer's ankle: en pointe (maximum PF), in neutral position, and in demi-plié (maximum DF). Using graphics software, a subject's three X-ray images were superimposed and the tali were aligned. On each image the tibia, navicular, intermediate cuneiform, and first metatarsal were marked. Positional differences of a bone's line among the three images demonstrated angular movement of the bone in degrees. The neutral position was the reference from which PF and DF of the bones were calculated.

RESULTS

The talocrural joint contributed the most motion of any pair of bones evaluated for both PF and DF, with mean movements of 57.6 ± 5.2 degrees en pointe and 24.6 ± 9.6 degrees in demi-plié. Approximately 70% of total PF and DF were attributable to the talocrural joint, with the remaining 30% coming from motion between adjacent pairs of the studied foot bones.

CONCLUSION

Superimposed X-rays for assessing ankle and foot contributions to the extreme positions required of female ballet dancers offer insight into how these positions are attained that is not available via goniometry.

CLINICAL RELEVANCE

Functional information gained from this study may assist clinicians in assessing ankle and foot pain in these individuals.

Pathoanatomy of posterior ankle impingement in ballet dancers

Dance is a high performance athletic activity that leads to great numbers of injuries, particularly in the ankle region. One reason for this is the extreme range of ankle motion required of dancers, especially females in classical ballet where the en pointe and demi-pointe positions are common. These positions of maximal plantar flexion produce excessive force on the posterior ankle and may result in impingement, pain, and disability. Os trigonum and protruding lateral talar process are two common and well-documented morphological variations associated with posterior ankle impingement in ballet dancers. Other less well-known conditions, of both bony and soft tissue origins, can also elicit symptoms. This article reviews the anatomical causes of posterior ankle impingement that commonly affect ballet dancers with a view to equipping healthcare professionals for improved effectiveness in diagnosing and treating this pathology in a unique type of athlete.

The illusion of weightlessness

The ballet pointe shoe is an interesting example of a product that has developed from the experimentation of a dancer to extend the art form. Over time, as the use of such a shoe became part of the tradition the form stagnated and there was little formal interaction with the user as to its continued effectiveness in terms of injury, cost and fit. This work re-examines the shoe from the dancer's point of view and demonstrates a way forward that illustrates that even with severe constraints the designer with a user-centred approach can improve the performance of a product whilst maintaining a required external aesthetic.

Incidence of anterior cruciate ligament injuries among elite ballet and modern dancers: a 5-year prospective study

BACKGROUND

Ballet and modern dance are jump-intensive activities, but little is known about the incidence of anterior cruciate ligament (ACL) injuries among dancers.

HYPOTHESIS

Rigorous jump and balance training has been shown in some prospective studies to significantly reduce ACL injury rates among athletes. Dancers advance to the professional level only after having achieved virtuosic jump and balance technique. Therefore, dancers on the elite level may be at relatively low risk for ACL injury.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Dance exposure, injuries, and injury conditions were systematically recorded at 4 dance organizations over 5 years. Select neuromuscular and psychometric variables were compared between and within ACL-injured and noninjured dancers.

RESULTS

Of 298 dancers, 12 experienced an ACL injury over the 5-year period. The incidence of ACL injury was 0.009 per 1000 exposures. Landing from a jump onto 1 leg was the mechanism of injury in 92% of cases. Incidence was not statistically different between gender or dance groups, although women modern dancers had a 3 to 5 times greater relative risk than women ballet dancers and men dancers. No difference between ACL-injured and noninjured dancers emerged with regard to race, oral contraceptive use, or select musculoskeletal measures.

CONCLUSION

Dancers suffer considerably fewer ACL injuries than athletes participating in team ball sports. The training dancers undertake to perfect lower extremity alignment, jump, and balance skills may serve to protect them against ACL injury. Anterior cruciate ligament injuries happened most often late in the day and season, suggesting an effect of fatigue.

Caring for the dancer: special considerations for the performer and troupe

The needs of a dancer patient can be daunting to the uninitiated physician. A dancer's technique, environment, and mentality are unique among athletes. Compared with popular team sports, like football or basketball, physicians are often unfamiliar with dancers' injuries and requirements to facilitate a safe, timely return to dance. The goal of this article is to help foster better communication between dancers and the medical community by describing dance epidemiology, dance basics including technique and characteristics, and some specific dance injuries.

Injury patterns in elite preprofessional ballet dancers and the utility of screening programs to identify risk characteristics

STUDY DESIGN

Retrospective descriptive cohort study.

OBJECTIVES

To describe the distribution and rate of injuries in elite adolescent ballet dancers, and to examine the utility of screening data to distinguish between injured and noninjured dancers.

BACKGROUND

Adolescent dancers account for most ballet injuries. Limited information exists, however, regarding the distribution of, rate of, and risk factors for, adolescent dance injuries.

METHODS AND MEASURES

Two hundred four dancers (age, 9-20 years) were screened over 5 years. Screening data were collected at the beginning and injury data were collected at the end of each training year. Descriptive statistics were used to characterize distribution and rate of injuries. Inference statistics were used to examine differences between injured and noninjured dancers.

RESULTS

Fifty-three percent of injuries occurred in the foot/ankle, 21.6% in the hip, 16.1% in the knee, and 9.4% in the back. Thirty-two to fifty-one percent of the dancers were injured each year, and, over the 5 years, there were 1.09 injuries per 1000 athletic exposures, and 0.77 injuries per 1000 hours of dance. Significant differences between injured and noninjured dancers were limited to current disability scores (P = .007), history of low back pain (P = .017), right foot pronation (P = .005), insufficient right-ankle plantar flexion (P = .037), and lower extremity strength (P = .045).

CONCLUSION

Distribution of injuries was similar to that of other studies. Injury rates were lower than most reported rates, except when expressed per 1000 hours of dance. Few differences were found between injured and noninjured dancers. These findings should be considered when designing and implementing screening programs.

The effect of an inclined landing surface on biomechanical variables during a jumping task

BACKGROUND

Professional dancers sustain a high number of injuries. Epidemiological studies have suggested that performing on inclined "raked" stages increases the likelihood of injury. However, no studies have examined if biomechanical differences exist between inclined and flat surfaces during functional tasks, such as landing from a jump. Such differences may provide a biomechanical rationale for differences in injury risk for raked stages.

METHODS

Eight professional dancers performed drop jumps from a 40cm platform on flat and inclined surfaces while forces, lower extremity kinematics, and electromyographic activity were collected in a controlled laboratory environment.

FINDINGS

Dancers landed on the laterally inclined surface with significantly higher knee valgus (4 degrees ), peak knee flexion (9 degrees ), and medial-lateral ground reaction force (GRF) (13.4% body weight) compared to the flat condition. The posterior GRF was higher in the anterior inclined condition compared to the flat condition. In the anterior inclined condition, subjects landed with 1.4 degrees higher knee valgus, 4 degrees more plantarflexion at initial contact, and 3 degrees less dorsiflexion at the end of landing.

INTERPRETATION

Biomechanical variables that have been suggested to contribute to injury in previous studies are increased in the inclined floor conditions. These findings provide a preliminary biomechanical rationale for differences in injury rates found in observational studies of raked stages.

The influence of second toe and metatarsal length on stress fractures at the base of the second metatarsal in classical dancers

BACKGROUND

Stress fractures at the base of the second metatarsal frequently occur in female classical dancers. There is a strong belief that a foot shape in which the first metatarsal or toe is shorter than the second metatarsal or toe increases the risk of this injury in dancers. However, there is a lack of empirical evidence to support this theory. The objective of this study was to examine the influence of the relative length difference between the first and second metatarsals and first and second toes on the frequency of stress fractures at the base of the second metatarsal in elite, female classical dancers.

METHODS

Both feet of 50 elite female classical dancers were measured for length differences between the first and second toes and first and second metatarsals. Retrospective analysis of dancers' medical histories revealed 17 feet with stress injury and 83 without. The mean of the difference between the metatarsal and toe length for the stress-injury group was compared to that of the control group.

RESULTS

No difference between the groups was identified for first and second toe length difference (p = 0.865) and the relative difference between the ends of the first two metatarsals (p = 0.815).

CONCLUSIONS

Dancers who had a stress injury at the base of the second metatarsal displayed similar variances in the two independent variables as dancers who had not had such an injury.

Management of a delayed-union sesamoid fracture in a dancer

BACKGROUND

Misdiagnosed o sesamoid bone pathology in dancers may result in prolonged pain, disability, and career limitation. A thorough understanding of sesamoid disorders and appropriate treatment facilitates timely recovery. The potential loss of hallux plantar flexion strength consequent to sesamoidectomy is a major consideration for dancers.

CASE DESCRIPTION

An 18-year-old dance student sustained a delayed-union fracture of her lateral (fibular) sesamoid. Treatment included an inductive coupling external bone stimulator with pulsed electromagnetic field, activity, and weight-bearing restrictions, protective padding, strengthening, functional retraining, and progressive return to dance.

OUTCOME

Following use of an external bone stimulator for 12 months, the dancer successfully returned to her previous level of dancing. Repeated SF-36 and Dance Functional Outcome System scores confirmed this improvement.

DISCUSSION

Loss of hallux plantar flexion strength with sesamoid resection can be devastating to a dancer who requires push-off strength for multiple turns and jumps. Treatment with bone stimulation was therefore selected over more invasive measures. The dancer was compliant with systematic functional progression. Improvement, as seen on radiographs and outcome scores, accompanied her full functional recovery.

A systematic review on ankle injury and ankle sprain in sports

This article systematically reviews epidemiological studies on sports injury from 1977 to 2005 in which ankle injury was included. A total of 227 studies reporting injury pattern in 70 sports from 38 countries were included. A total of 201,600 patients were included, with 32,509 ankle injuries. Ankle injury information was available from 14,098 patients, with 11 847 ankle sprains. Results show that the ankle was the most common injured body site in 24 of 70 included sports, especially in aeroball, wall climbing, indoor volleyball, mountaineering, netball and field events in track and field. Ankle sprain was the major ankle injury in 33 of 43 sports, especially in Australian football, field hockey, handball, orienteering, scooter and squash. In sports injuries throughout the countries studied, the ankle was the second most common injured body site after the knee, and ankle sprain was the most common type of ankle injury. The incidence of ankle injury and ankle sprain was high in court games and team sports, such as rugby, soccer, volleyball, handball and basketball. This systematic review provides a summary of the epidemiology of ankle injury in sports.