Foot and Ankle Injuries in Dance

Cueing Dancers to "Externally Rotate From the Hips" Improves Potentially Injurious Ankle Joint Angles and Contact Forces During a Demipointe Ballet Position

Introduction: The demipointe dance position puts the ankle at high risk of overuse injury and posteromedial ankle pain due to increased ankle valgus forces. Previous work has shown that creating lower limb external rotation intrinsic to demipointe with hip external rotation reduces foot pronation that causes ankle valgus stress. Therefore, the purpose of this work was to examine long axis rotation kinematics of the hip, knee, and ankle as well as the ankle joint contact forces in demipointe to better understand the biomechanical impact(s) of the specific cue to increase hip external rotation in this position. Methods: Three-dimensional motion capture and force plate data were collected from 23 contemporary or ballet pre-professional dancers (age: 19.94 ± 1.34 years) who each performed 3 dancer-selected (DS) demipointe positions and 3 demipointes with the cue to "externally rotate from the hips." Results: The cue to increase hip external rotation resulted in significantly increased hip external rotation angle [DS: 37.5; 9.42° (median; interquartile range), Cued: 39.9; 10.8°, P < .0001)] and significantly reduced ankle eversion angle (DS: 8.13; 11.4°, Cued: 7.77; 10.3°, P = .023). However, total turnout angle was also significantly decreased (DS: 75.8; 7.91°, Cued: 75.4; 7.73°, P < .0001), which is undesirable for proper esthetic performance of demipointe. Total ankle joint force remained unchanged, but ankle eversion force was significantly reduced (DS: 15.3; 4.18 %bodyweight (BW), Cued: 14.7; 4.99 %BW, P < .0001) with use of the cue. Discussion/Conclusion: Utilization of a cue to increase hip external rotation was successful in increasing hip contribution to turnout angle and reducing injurious ankle eversion force. Further coaching using this cue may allow dancers to produce these advantageous mechanics while maintaining turnout angle.

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.

An Achilles Tendinopathy Educational Intervention for Generalist Physicians Raises Awareness and Improves Knowledge for Treating Ballet Dancers

BACKGROUND

Achilles tendinopathy can be a devastating condition in ballet dancers. Initial medical evaluation is frequently conducted by generalist physicians, who may lack the perspective of dance and sports medicine focused training and often prescribe complete rest for chronic overuse injuries. In order to provide targeted information about Achilles tendinopathy and the unique needs of elite athletes, such as ballet dancers, we designed an educational intervention that covers relevant anatomy, physiology, biomechanics, clinical presentation and evaluation, and recommendations for initial treatment and sub-specialty referral. The objectives of this study were to determine baseline understanding of Achilles tendinopathy by generalist physicians and to evaluate the efficacy of an educational intervention on their knowledge.

METHODS

This was a prospective pre- post-test study, to measure improvement in knowledge about Achilles tendinopathy. Emergency Medicine and Primary Care physicians participated in an educational intervention with didactic and hands-on components. Data were analyzed using a two-tailed t-test.

RESULTS

Twenty generalist physicians participated. There was significant improvement in their knowledge of Achilles tendinopathy for all our educational objectives (Pre-test: 59% correct answers; post-test: 79% correct answers; P < .0001; 95% CI: 6.32-10.78.).

CONCLUSIONS

A brief educational intervention leads to increased knowledge of Achilles tendinopathy in generalist physicians. By increasing awareness of Achilles tendinopathy through a standard educational model, we propose that our curriculum can be portable and accessible to all health care providers who encounter dancers and other athletes with Achilles tendinopathy and may serve as a model for expanded education to generalists about other conditions commonly encountered in ballet dancers.

Injury incidence and severity in Chinese pre-professional dancers: A prospective weekly monitoring survey

OBJECTIVES

To determine dance injury incidence and severity in full-time Chinese pre-professional dancers.

STUDY DESIGN

Prospective weekly online monitoring survey.

METHODS

Respondents were asked to record all dance-injury incidences between September 2020 and July 2021 using a remote weekly self-report injury monitoring tool. An inclusive definition of injury was used in this study to record all injuries, even if they didn't cause a cessation of training. Data were excluded if respondents completed <90 % of the survey period and had over 3 consecutive weeks of missing data.

RESULTS

450 individuals from 11 different schools were included in the analyses. A total of 1157 injuries were reported over a 30-week academic year. Injury prevalence was 64.9 % and injury incidence was 5.51 injuries per 1000 h. Forty-eight percent of the injuries were minor severity and 41 % were of moderate severity, and the main injury sites were knees (0.89/1000 h), lower back (0.80/1000 h), feet (0.58/1000 h) and groin (0.56/1000 h). Female dancers reported significantly higher injury prevalence and injury incidence, and higher rates of moderate to severe injuries than males. The university group reported higher injury incidence than the adolescent group (p < 0.05), whereas the latter reported higher rates of moderate to severe injuries than the former (p < 0.001).

CONCLUSIONS

The injury incidence found in this study (5.1 injuries/1000 h) is higher than most previous sets of data. Female dancers are at a higher risk of injury and reported higher levels of injury severity than male dancers, especially for the female adolescent group.

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.

Dance-Related Foot and Ankle Injuries and Pathologies

Dancers are highly vulnerable to injuries due to high dynamic overload, extreme positions and motions, and excessive use. Increased load at the forefoot with jumping and high-impact lands can cause sesamoiditis and stress fractures of the metatarsals. Significant plantarflexion can lead to posterior joint impingement and flexor hallucis longus tendonitis, whereas forced dorsiflexion can cause anterior joint impingement. Most pathologies can be diagnosed on physical examination and various imaging modalities. Treatment should be tailored to the dancers' needs and should begin with a course of conservative therapy with immobilization, physical therapy, and activity cessation.

Alignment of the metatarsal heads affects foot inversion/eversion during tiptoe standing on one leg in demi-pointe position: A cross-sectional study on recreational dancers

Classical ballet dancers stand on tiptoe in the demi–pointe position where the ankle is plantarflexed, and the toes extend around a mediolateral axis passing through the second metatarsal head. Foot sickling, the foot inversion/eversion when the forefoot is grounded, should be avoided to achieve esthetics and prevent injuries during tiptoe standing. The foot inversion/eversion angle may change depending on the metatarsal heads through which the toe extension axis passes. This study investigated the relationship between metatarsal alignment in both load positions and foot inversion/eversion angle during tiptoe standing. Nine recreational female ballet dancers performed tiptoe standing on a single leg in the demi–pointe position. The foot inversion/eversion angle, the centre of pressure (COP) positions, and angles between adjacent metatarsal heads in the horizontal plane were investigated using motion–capture data and magnetic resonance imaging of the forefoot. As the angle between the second and adjacent metatarsal heads became more acute during tiptoe standing on the non-dominant leg, the dancers everted the foot more and significantly loaded the first toe–side more, and vice versa (r = −0.85 and −0.82, respectively). Then, the load positions were distributed on the distal side of the second metatarsal head. These were not seen during standing on the dominant leg with COPs more proximal to the second metatarsal head. In conclusion, dancers load the distal part of the second metatarsal head during tiptoe standing on the non–dominant leg. When the angle at the second metatarsal head was acute, within the triangle formed by the first, second, and third metatarsal heads, even slight mediolateral shifts of load positions altered the toe extension axis around that metatarsal head; the dancers loaded medial to the second metatarsal head and everted the foot and vice versa. Therefore, the angle between the second and adjacent metatarsal heads influenced the foot inversion/eversion angle.

Comparison of hallux valgus deformed ballerinas and sedentary individuals in terms of balance parameters

BACKGROUND

We aimed to compare static and dynamic balance parameters and health quality parameters in ballerina and non-ballerina adolescents with hallux valgus deformity.

METHODS

Forty five volunteer female adolescent ballet students between the ages of 7 and 17, with hallux valgus were recruited. Group 1 = in the control group, 31 sedentary adolescents with hallux valgus were included. Group 2 = Romberg test and Flamingo test were used for static balance. The SEBT (Star Excursion Balance Test) was used to measure dynamic balance.

RESULTS

Age, sex, and body mass index (BMI) characteristics were similar between ballerina and control groups (P < .05). The Romberg test stands upright with closed eyes, with a significant difference 47.22 in group 1 and 38.13 in group 2. In contrast there was a significant difference between the two groups in the Romberg test single limb with eyes open and closed. For open eyes single limb test mean score was 55.06 in ballerinas and 44.2 in sedentary group, similarly single limb test with closed eyes mean score was 25.68 in group 1 and 18.67 in group 2.

CONCLUSION

In conclusion, the results of this study show that ballerinas have better single-limb and closed-eye balance than sedentary individuals with HV deformities.

Comparison of Dance-Related Foot and Ankle Injuries Among Pre-Professional Ballet, Contemporary, and Chinese Dancers

BACKGROUND

Foot and ankle injuries have been noted as the most common in dancers. However, the variability of injury epidemiology across different dance genres has not been clearly evaluated. Herein, this study aimed to evaluate the prevalence and incidence of foot and ankle problems in pre-professional ballet, contemporary, and Chinese dancers.<br/> Methods: Participants (N = 54) were recruited from a local dance institution that offered a formal undergraduate dance program. Demographic characteristics and specifics of foot and ankle pain during dancing were collected through an online self-reporting survey from September 2018 to June 2019. Descriptive statistical analyses, including injury incidence and risk rates, were conducted.<br/> Results: The overall response rate was 69.3%, with a total of 88 subjects eligible for analysis of which the results from 54 subjects were ultimately analyzed. The incidence of foot and ankle pain during the academic year of 2018 to 2019 was highest in contemporary dancers (0.38 per 1,000 dance hours) when compared to that of ballet (0.32 per 1,000 dance hours) and Chinese dancers (0.22 per 1,000 dance hours). Prevalence of foot and ankle pain within the same year was 84% in ballet dancers, 79% in Chinese dancers, and 70% in contemporary dancers. Ballet dancers were six times more likely to suffer from pain in the Achilles region than Chinese and contemporary dancers (p < 0.01). Chinese dancers were found to experience more forefoot and midfoot problems compared to ballet and contemporary dancers (p < 0.05).<br/> Conclusion: This study illustrated that foot and ankle pain is highly prevalent among pre-profes- sional dancers. Ballet was associated with the highest prevalence of foot-ankle pain while contemporary dance was associated with the highest incidence. There were significant differences of foot and ankle pain among dance genres and anatomical subregions, which suggests a need for targeted genre-specific injury prevention programs in hopes of preventing potentially career-ending injuries in dancers.

Biomechanical Risks Associated with Foot and Ankle Injuries in Ballet Dancers: A Systematic Review

Professional ballet dancers can be classified as dance artists and sports performers. This systematic review aims to consider the biomechanical risk factors for foot and ankle injuries in ballet dancers, as this could potentially reduce the impact that ‘cost of injury’ may have on ballet companies. An additional outcome was to examine the effects of injury on the career of ballet dancers. This study searched articles in four electronic databases for information in peer-reviewed journals. The included articles examined the relationships between biomechanical factors and the relationship between ballet shoes and foot performance. There were 9 articles included in this review. Among these articles, two focused on the peak force of the foot using two types of pointe shoes, three focused on overuse injuries of the ballet dancer’s foot, one article focused on the loading of the foot of a dancer, and three articles focused on the function and biomechanics of the foot in dancers. This review also found that the pointe shoe condition was the most important factor contributing to a foot injury; overuse injury related to high-intensity training and affected both the ankle and the foot; and metatarsophalangeal joint injury related to the function and structure of the foot. Finally, strengthening the lower extremity muscle is also a recommendation to improve muscle coordination and reduce injuries.

Effect of Integrated Training on Balance and Ankle Reposition Sense in Ballet Dancers

OBJECTIVE

To investigate the effects of a 6-week integrated training program on the ankle joint reposition sense and postural stability in ballet dancers.

METHODS

Sixteen female ballet dancers participated in the study and underwent a 6-week integrated training program consisting of plyometric, proprioception and core stability exercises along with a home program involving additional ankle muscle strengthening and stretching. The ankle joint reposition tests and the parameters of the center of pressure (COP) while performing grand-plie (deep squatting) and releve en demi-pointe (standing on balls of foot) movements were measured before and after training.

RESULTS

After 6 weeks, participants showed significantly smaller absolute ankle joint reposition errors in dorsiflexion (p = 0.031), plantarflexion (p = 0.003) and eversion (p = 0.019) compared to the pre-training measurement. Furthermore, after training, a significantly slower average COP speed at pre-equilibrium during grand-plie movement (p = 0.003) and pre-equilibrium phase of releve en demi-pointe (p = 0.023) were observed. In addition, the maximum COP displacement in the medial-lateral direction was significantly smaller at pre-equilibrium phase during grand-plie (p = 0.044) and releve en demi-pointe movements (p = 0.004) after training.

CONCLUSIONS

The 6-week integrated training program improved the ankle joint reposition sense and postural control in the medial-lateral direction during grand-plie and releve en demi-pointe movements.

Effects of a "toes-off" modified heel raise on muscle coordination in non-dancers, dancers, and dancers with flexor hallucis longus tendinopathy

BACKGROUND

Tendinopathy of the flexor hallucis longus, commonly called "dancer's tendinitis", is a prevalent injury among female ballet dancers. Limited success of non-surgical interventions leads to many dancers undergoing tenolysis surgeries with risks and recovery times that can be detrimental to a dance career. The purpose of this study was to evaluate lower limb kinematics and muscle coordination during a modified traditional heel raise exercise where the toes hang off the edge of the support surface. We hypothesized this would decrease activation of the flexor hallucis longus and increase activation of larger plantarflexors.

METHODS

Healthy non-dancers (n = 11), healthy dancers (n = 10), and dancers with flexor hallucis longus tendinopathy (n = 9) performed traditional ("toes-on") and modified ("toes-off") heel raises with kinematic and electromyographic instrumentation of the lower leg.

FINDINGS

Participants maintained ankle excursion with the toes-off modification, while metatarsophalangeal joints had reduced excursion and greater excursion variability. Most healthy dancers (9/10) decreased flexor hallucis longus activation as predicted, but dancers with flexor hallucis longus tendinopathy showed a variable response with some decreasing activation (3/9) but others increasing activation up to 4-times. There were no changes in activation of other plantarflexors. Across groups, intrinsic foot muscle activation decreased with the toes-off modification.

INTERPRETATION

The toes-off modification decreased flexor hallucis longus activation in most of the healthy dancers but was insufficient to shift muscle coordination from the flexor hallucis longus to larger plantarflexors in dancers with flexor hallucis longus tendinopathy. Future work should investigate clinical cues or modifications to this "toes-off" heel raise intervention.

What goes up must come down, part II: Consequences of jump strategy modification on dance leap landing biomechanics

Knee injuries are common in jumping athletes; modifying jump strategy may impact loads placed on the body and reduce injury risk. The purpose of this study was to determine if modifying strategy in a saut de chat leap to focus on height would decrease sagittal plane knee loading. Biomechanical data were collected while 28 dancers performed saut de chat leaps with instructions to jump far (FAR) or jump high (UP). In the UP condition, there was greater vertical GRF and less braking GRF. Also in UP, lower extremity contact angle was greater (71.3 ± 2.9º FAR; 75.8 ± 3.3º UP; p = 0.0178), peak knee extensor moment was greater (2.8 ± 0.7 Nm FAR; 3.2 ± 0.8 Nm UP; p = 0.01), and peak ankle plantar flexor moment was lower (3.19 ± 0.4 Nm FAR; 2.94 ± 0.4 Nm UP; p < 0.01). A more acute LECA was related to greater braking force and braking force was related to greater knee extensor moments. Despite these relationships, we observed greater knee extensor moments in UP. While the relationship among these whole-body variables and knee joint loading exists, it may not be the primary factor driving load distribution during dance leap landings.

Mechanical Demands at the Ankle Joint During Saut de Chat and Temps levé Jumps in Classically Trained Ballet Dancers

Background

During ballet, injuries to the Achilles tendon are associated with the take-off phase of various jumps.

Research question

The purpose of the study was to assess differences in mechanical demand on the body, specifically at the ankle, in two single-leg jumps commonly trained in ballet: a saut de chat (SDC) and a temps levé (TL).

Methods

Fifteen classically trained female dancers had 16 reflective markers placed on the lower body and each dancer performed each jump three times on a force plate. The marker position data and ground reaction forces (GRF) were captured synchronously at 250 Hz and 1000 Hz, respectively. Peak vertical GRF, mean rate of force development (RFD), peak ankle moment, and peak ankle power were determined and averaged across trials. Paired t-tests were used to determine differences between the SDC and the TL.

Results

When compared to the TL, the SDC displayed significantly higher peak vertical GRF (p = 0.003), RFD (p = 0.002), and peak ankle moment and power (p < 0.001). The effect sizes for these differences were large for all variables (Cohen’s d > 0.80).

Conclusion

The mechanical demand at the ankle joint is significantly greater for the SDC than the TL.

Acute Effect of Toe Cap Choice on Toe Deviation Angle and Perceived Pain in Female Professional Ballet Dancers

Several classical dance complex movements, such as pointe, require body weight to be supported properly to avoid risk of foot injury. Regarding the choice of toe cap for pointe shoes, it is unclear which type can better alleviate pain symptoms and toe deviation angle in dancers. The aim of the current crossover study was to investigate the acute effect of using different types of toe caps among well-trained professional dancers on pain perception and toe deviation angle. Ten young female professional dancers volunteered to participate in the study. Each participant was tested during two separate sessions with an interval of 72 h in between. Participants were tested in the two sessions with a standard commercial or a customized prototype toe cap, always with pointe shoes, and in randomized order. An anteroposterior X-ray examination was performed separately for each participant and a visual analogue scale for pain perception was administered following each situation (with a standard commercial or a customized prototype toe cap). Significant amelioration was obtained when a customized toe cap prototype was used both for toe deviation angle and for visual analogue scale. Use of a customized toe cap prototype compared to a standard one may acutely reduce both toe deviation angle and pain in elite female professional dancers.

Lower extremity biomechanics and muscle activity differ between 'new' and 'dead' pointe shoes in professional ballet dancers

The purpose of this study was to compare lower extremity (LE) biomechanics and muscle activity between 'new' and 'dead' pointe shoes in professional female ballet dancers performing relevé and arabesque. We compared sway area, peak ankle moments, and tibialis anterior and medial gastrocnemius muscle activation amplitudes. Nine ballet dancers participated (age = 22.2 ± 2.2 years, height = 163.2 ± 6.3 cm, body mass = 50.8 ± 6.5 kg) executed three trials of relevé and arabesque on pointe shoes under two conditions: 'dead' (108-144 training hours) and 'new' (3-36 training hours). While wearing 'dead' pointe shoes, dancers had significantly higher sway area during both relevé and arabesque (p = 0.017 and 0.028, respectively). Dancers exhibit significantly higher tibialis anterior activation (root mean square, %maximum voluntary contraction) during arabesque while wearing 'dead' pointe shoes (p = 0.043). No significant differences were identified in other dependent variables. The increased sway area and tibialis anterior muscle activity when wearing 'dead' pointe shoes during relevé and arabesque movements demonstrates that using 'dead' shoes is more demanding. Our findings provide quantitative evidence of possible deleterious biomechanical changes when wearing dead pointe shoes that may increase LE injury risk in dancers.

Overuse Injuries in Professional Ballet: Influence of Age and Years of Professional Practice

Background:

In spite of the high rate of overuse injuries in ballet dancers, no studies have investigated the prevalence of overuse injuries in professional dancers by providing specific diagnoses and details on the differences in the injuries sustained as a function of age and/or years of professional practice.

Hypothesis:

Overuse injuries are the most prevalent injuries in ballet dancers. Professional ballet dancers suffer different types of injuries depending on their age and years of professional practice.

Study Design:

Descriptive epidemiology study.

Methods:

This descriptive epidemiological study was carried out between January 1, 2005, and October 10, 2010, regarding injuries sustained by professional dancers belonging to the major Spanish ballet companies practicing classical, neoclassical, contemporary, and Spanish dance. The sample was distributed into 3 different groups according to age and years of professional practice. Data were obtained from the specialized medical care the dancers received from the Trauma and Orthopaedic Surgery Service at Fremap in Madrid. The dependent variable was the study of the injury.

Results:

A total of 486 injuries were identified over the study period, with overuse injuries being the most common etiology (P < .0001); these injuries were especially prevalent in junior professional dancers practicing classical ballet and veteran dancers practicing contemporary ballet (P = .01). Specifically, among other findings, stress fractures of the base of the second metatarsal (P = .03), patellofemoral syndrome, and os trigonum syndrome were more prevalent among junior professionals (P = .04); chondral injury of the knee in senior professionals (P = .04); and cervical disc disease in dancers of intermediate age and level of experience.

Conclusion:

Overall, overuse injuries were more prevalent in younger professionals, especially in women. This finding was especially true for the more technical ballet disciplines. On the other hand, in the athletic ballet disciplines, overuse lesions occurred mainly in the more senior professionals.

Clinical Relevance:

This study provides specific clinical diagnoses obtained through physical examination as well as details on the different injury types sustained as a function of age and/or years of professional practice, an important aspect for ballet and sports practice in general.

Pathologic Disorders of the Foot in Professional Female Flamenco Dancers

BACKGROUND

The foot is the main element of artistic creation in flamenco dancing. At the professional level, the foot undergoes high musculoskeletal demands, predisposing the development of podiatric pathologic disorders in this group. The principal objective of this study was to determine the most common foot lesions in professional female flamenco dancers.

METHODS

In a cross-sectional observational study of 44 female professional flamenco dancers, the participants completed a short questionnaire about their demographic features, number of hours danced per week, and years of professional activity. Any foot lesions presented by the participant were also recorded.

RESULTS

Some type of pathologic foot condition was noted in 75% of the women, with a particularly high prevalence of hallux abducto valgus (61.4%), hypermobility of the first ray (43.2%), claw toe (40.9%), and varus fifth toe (37.5%) compared with the general population. No significant differences in the presence of pathologic disorders of the foot were found according to the time dedicated to dance or the years of professional activity.

CONCLUSIONS

Female flamenco dancers in this study had a high prevalence of podiatric medical problems: some kind of pathologic abnormality of the foot was present in 75% of the participants. Hallux abducto valgus, claw toe, and hypermobility of the first ray were the most common pathologic disorders observed.

An assessment of hallux limitus in university basketball players compared with noncompetitive individuals

BACKGROUND

Injuries of the first metatarsophalangeal joint have lately been receiving attention from researchers owing to the important functions of this joint. However, most of the studies of turf toe injuries have focused on sports played on artificial turf.

METHODS

This study compared the range of motion of the first metatarsophalangeal joint in collegiate basketball players (n = 123) and noncompetitive individuals (n = 123).

RESULTS

A statistically significant difference (P < .001) in range of motion was found between the two groups. The difference between the two sample means was 21.35°.

CONCLUSIONS

With hallux rigidus being a potential sequela of repeated turf toe injuries, it seems likely that subacute turf toe injuries occur in basketball players, leading to degenerative changes that result in hallux limitus.

Kinematic and kinetic analyses of the toes in dance movements

Due to the significant amount of time dancers spend on the forefoot, loads on the metatarsophalangeal joints are likely high, yet vary between dance movements. The purpose of this study was to compare joint motion and net joint moments at the metatarsophalangeal joints during three different dance movements ranging in demands at the foot and ankle joints. Ten healthy, female dancers (27.6 ± 3.2 years; 56.3 ± 6.9 kg; 1.6 ± 0.1 m) with an average 21.7 ± 4.9 years of dance training performed relevés (rising up onto the toes), sautés (vertical bipedal jumps), and saut de chat leaps (split jumps involving both vertical and horizontal components). Metatarsophalangeal joint kinematics and kinetics in the sagittal plane were calculated. Total excursion and peak net joint moments during rising or push-off were compared between the three dance movements. Greater extension of the metatarsophalangeal joints was seen during relevés compared to sautés or saut de chat leaps, and the largest metatarsophalangeal net joint moments were seen during saut de chat leaps. The metatarsophalangeal joints frequently and repetitively manage external loads and substantial metatarsophalangeal extension during these three dance movements, which may contribute to the high rate of foot and ankle injuries in dancers.

Postural adjustments in young ballet dancers compared to age matched controls

OBJECTIVES

The purpose of the study was to use photogrammetry to evaluate the posture of ballet practitioners compared to an age-matched control group.

DESIGN

One hundred and eleven 7- to 24-year-old female volunteers were evaluated and were divided into two groups: the ballet practising group (n = 52) and the control group (n = 59), divided into three subgroups according to age and years of ballet experience.

RESULTS

Dancers with 1-3 years experience compared to controls of the same age shows alterations in External Rotation Angle (P < 0.05). Dancers 4-9 years experience show alterations in Lumbar Lordosis, Pelvis Tilt Angle and Navicular Angle Right and Left (P < 0.05). Dancers with over 9 years experience show alterations in External Rotation and Navicular Angle Left (P < 0.05).

CONCLUSIONS

Research shows there are differences between dancers and controls. In the groups 1-3 years and over 9 years of experience, the External Rotation Angle is greater. In the group 4-9 years of experience the Lumbar Lordosis Angle is greater and Pelvis Tilt, Navicular Angle Left and Right are smaller. In more than 9 years of ballet experience, the Navicular Angle Left is smaller.

Overuse Injuries in Professional Ballet: Injury-Based Differences Among Ballet Disciplines

Background

Despite overuse injuries being previously described as the most frequent in ballet, there are no studies on professional dancers providing the specific clinical diagnoses or type of injury based on the discipline.

Hypothesis

Overuse injuries are the most frequent injuries in ballet, with differences in the type and frequency of injuries based on discipline.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

This was a descriptive cross-sectional study performed between January 1, 2005, and October 10, 2010, on injuries occurring in professional dancers from leading Spanish dance companies who practiced disciplines such as classical, neoclassical, contemporary, and Spanish ballet. Data, including type of injury, were obtained from specialized medical services at the Trauma Service, Fremap, Madrid, Spain.

Results

A total of 486 injuries were evaluated, a significant number of which were overuse disorders (P < .0001), especially in the most technically demanding discipline of classical ballet (82.60%). Injuries were more frequent among female dancers (75.90%) and classical ballet (83.60%). A statistically significant prevalence of patellofemoral pain syndrome was found in the classical discipline (P = .007). Injuries of the adductor muscles of the thigh (P = .001) and of the low back facet (P = .02) in the Spanish ballet discipline and lateral snapping hip (P = .02) in classical and Spanish ballet disciplines were significant.

Conclusion

Overuse injuries were the most frequent injuries among the professional dancers included in this study. The prevalence of injuries was greater for the most technically demanding discipline (classical ballet) as well as for women. Patellofemoral pain syndrome was the most prevalent overuse injury, followed by Achilles tendinopathy, patellar tendinopathy, and mechanical low back pain.

Clinical Relevance

Specific clinical diagnoses and injury-based differences between the disciplines are a key factor in ballet.

Risk factors for tibial stress injuries: a case-control study

OBJECTIVE

To identify physical and behavioral characteristics related to the incidence of tibial stress injuries (TSIs).

DESIGN

Case-control study. No clinical care was conducted.

SETTING

Research laboratories in the San Francisco (the United States) and Gold Coast (Australia) areas.

PARTICIPANTS

Forty-eight patients (21 men and 27 women) with acute TSI, and 36 (16 men and 20 women) age-matched, sex-matched, height-matched, weight-matched, and activity-matched controls with no history of TSI.

INDEPENDENT VARIABLES

Height, weight, body mass index, bone, lean and fat mass, lower limb alignment anomalies, foot type, orthotics, calcium, recent weight change, menstrual history, oral contraceptive use, medications, smoking, alcohol, sleep, training type, and intensity. Differences in continuous variables were tested using 1-way analysis of variance. Categorical variable comparisons were performed with Fisher exact test.

MAIN OUTCOME MEASURE

Tibial stress injury.

RESULTS

Tibial stress injury cases had 2.7% more fat (P < 0.001) and 2.6% less muscle (P < 0.001) as well as lower trochanteric bone mineral content (BMC) (P < 0.001), lumbar spine (LS) area (P < 0.001), femoral neck BMC (P < 0.001), length (P < 0.05), area (P < 0.001), cortical width (P < 0.01), cross-sectional moment of inertia (P < 0.001), and index of bending strength (P < 0.001) than controls. Controls had lower LS BMC (P < 0.01), length (P < 0.001), and broadband ultrasound attenuation (P < 0.001). The use of orthotic insoles was more prevalent in TSI cases than controls (25% vs 5.6%, respectively; P < 0.02), as were foot anomalies (56.3% vs 27.8%, respectively; P = 0.01).

CONCLUSIONS

Tibial stress injury cases had lower lean and higher fat mass, a tendency for smaller bones, and for foot anomalies compared with uninjured matched controls. bone mineral density was normal for both groups.

CLINICAL RELEVANCE

Enhancing lean mass and limiting gains in fat may provide some protection against TSI. Individuals with small skeletal frames are advised to increase training loads particularly gradually and to reduce training intensity at the first sign of pain in the shins.

Foot pain in the child and adolescent

There are multiple causes of pediatric foot and ankle pain. Although conservative measures are appropriate for initial management, patients with refractory pain should be given consideration for further intervention. This review highlights some of the most common causes of foot and ankle pain in the child, with specific attention to demographics, etiologies, diagnostic workup, and treatment options.

A comparative, prospective, and randomized study of two conservative treatment protocols for first-episode lateral ankle ligament injuries

BACKGROUND

The objective of this study was to investigate functional results, the amount of time that patients missed from regular working activities, and the incidence of residual mechanical ankle instability following conservative treatment of a first episode of severe lateral ankle ligament sprain (with articular instability).

METHODS

This prospective and randomized study included 186 patients with severe lateral ankle ligament injuries, who were randomly assigned into 2 conservative treatment groups. In group A, participants were treated with a walking boot with weight-bearing allowed, pain management, ice, and elevation with restricted joint mobilization for 3 weeks. In group B, patients were treated with a functional brace for 3 weeks. After this period, patients from both groups were placed in a short, functional brace for an additional 3 weeks, during which they also started a rehabilitation program.

RESULTS

No statistically significant difference was found in pain intensity score between the 2 groups; however, functional evaluations based on the AOFAS ankle and hindfoot score system showed a statistically significant improvement in the group treated with the functional brace. In addition, the average recovery period necessary for patients of group B to resume their duties was shorter than that for patients in group A. No significant difference was detected in residual mechanical ankle instability between the 2 groups.

CONCLUSION

Patients with severe lateral ankle ligament lesions treated with a functional brace were shown to exhibit somewhat better results than those treated with a walking boot, and both methods presented a very low incidence of residual chronic instability. We found adequate conservative treatment was sufficient to reestablish ankle stability and that functional treatment had a marginally better clinical short-term outcome with a shorter average recovery period.

LEVEL OF EVIDENCE

Level I, prospective randomized study.

The usefulness of performance matrix tests in locomotor system evaluation of girls attending a ballet school - preliminary observation

[Purpose] Learning ballet is connected with continuous use of the locomotor system while subjecting it to high loads. Therefore, we conducted some research defining the appearance of weak links in the motor system, in order to eliminate the risk of injury. [Methods] Fifty-two female students of a ballet school were examined. To identify weak links, low-threshold Performance Matrix tests were performed. An analysis of weak link occurrence in the locomotor system was carried out, using two way analysis of variance ANOVA Tukey's HSD test, clustering methods and Principal Component Analysis (PCA). [Results] The average age of the subjects was 11.64±0.53 years (mean ± standard deviation), their average body height was 151.1±7.5 cm, their average body weight was 35.92±5.41 kg, and their average time of learning at ballet school was 2.17±0.65 years. We found that there were significant differences in weak links occurrence in the motor system of every girl examined. [Conclusions] Weak links were found in every location of the motor system. Our results show that the influence of weak link location is essentially different from their occurrence, and that learning ballet has a significantly different impact on the number of weak links in different locations.

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.

Injuries in female dancers aged 8 to 16 years

CONTEXT

Most studies of injured dancers have been carried out on professional adult dancers; data on young, nonprofessional injured dancers are sparse.

OBJECTIVE

To identify the types of injuries sustained by recreational dancers and to examine their association with age, joint range of motion, body structure, age at menarche, presence of anatomic anomalies, and physical burden (i.e., practice hours en pointe).

DESIGN

Descriptive epidemiology study.

SETTING

The Israel Performing Arts Medicine Center, Tel Aviv.

PATIENTS OR OTHER PARTICIPANTS

A total of 569 injured female dancers, aged 8 to 16 years.

MAIN OUTCOME MEASURE(S)

Dependent variables were 61 types of current injuries that were later classified into 4 major categories: knee injuries, foot and ankle tendinopathy, back injuries, and other injuries. Independent variables were age, joint range of motion, body size and shape, age at menarche, anatomic anomalies, and dance discipline (e.g., hours of practice per week en pointe).

RESULTS

At least 1 previous injury had been sustained by 42.4% of the dancers. The most common injuries involved the knee (40.4%), followed by other injuries (23.4%). The relative frequency of back injuries and tendinopathy decreased with age, whereas knee injuries increased. Types of injuries were significantly associated with ankle plantar flexion, hip external rotation, hip abduction, and knee flexion. Multinomial regression analysis revealed only 3 predictive variables (with other as baseline), all for back injury: scoliosis, age, and hip external rotation.

CONCLUSIONS

Joint range of motion and scoliosis may signal the potential for future injury. Young dancers (less than 10 years of age) should not be exposed to overload (especially of the back) or extensive stretching exercises.

Lower limb kinematic variability in dancers performing drop landings onto floor surfaces with varied mechanical properties

Elite dancers perform highly skilled and consistent movements. These movements require effective regulation of the intrinsic and extrinsic forces acting within and on the body. Customized, compliant floors typically used in dance are assumed to enhance dance performance and reduce injury risk by dampening ground reaction forces during tasks such as landings. As floor compliance can affect the extrinsic forces applied to the body, secondary effects of floor properties may be observed in the movement consistency or kinematic variability exhibited during dance performance. The aim of this study was to investigate the effects of floor mechanical properties on lower extremity kinematic variability in dancers performing landing tasks. A vector coding technique was used to analyze sagittal plane knee and ankle joint kinematic variability, in a cohort of 12 pre-professional dancers, through discrete phases of drop landings from a height of 0.2m. No effect on kinematic variability was observed between floors, indicating that dancers could accommodate the changing extrinsic floor conditions. Future research may consider repeat analysis under more dynamic task constraints with a less experienced cohort. However, knee/ankle joint kinematic variability was observed to increase late in the landing phase which was predominantly comprised of knee flexion coupled with the terminal range of ankle dorsiflexion. These findings may be the result of greater neural input late in the landing phase as opposed to the suggested passive mechanical interaction of the foot and ankle complex at initial contact with a floor. Analysis of joint coordination in discrete movement phases may be of benefit in identifying intrinsic sources of variability in dynamic tasks that involve multiple movement phases.

Proximal base stress fracture of the second metatarsal in a Highland dancer

A 15-year-old female Highland dancer presented to the accident and emergency department with an ankle inversion injury on a background of several weeks of pain in the right foot. A radiograph of the right foot demonstrated a stress fracture at the base of the second metatarsal. She was treated conservatively with a below knee removable supportive walking boot with a rocker bottom sole. She re-presented to the accident and emergency department 3 weeks later with pins and needles in the right foot; she was given crutches to use along side the supportive walking boot. Radiographs 12 weeks after the first presentation showed healing of the stress fracture. The patient was now asymptomatic of the injury. She was unable to fully train for 12 weeks due to the injury. Conservative management was successful in this patient.

Dance floor mechanical properties and dancer injuries in a touring professional ballet company

OBJECTIVES

The mechanical properties of the floors used by dancers have often been suggested to be associated with injury, yet limited etiological evidence is available to support this hypothesis. The dance floors at three theatres regularly used by a touring professional ballet company were mechanically quantified with the aim of comparing floor properties with injury incidence in dancers.

DESIGN

Cross sectional.

METHODS

Test points on the floors were quantified in accordance with European Sports Surface Standard protocols for force reduction. Injuries and associated variables occurring within the ballet company dancers during activity on the three floors were recorded by the company's medical staff. An injury was recorded if a dancer experienced an incident that restricted the dancer from performing all normal training or performance activities for a 24 h period. Injuries were delimited to those occurring in the lower limbs or lumbar region during non-lifting tasks.

RESULTS

Floor construction varied between venues and a range of floor mechanical properties were observed. None of the floors complied with the range of force reduction values required by the European Sport Surface Standards. The highest injury rate was observed on the floor with the greatest variability of force reduction magnitudes. No difference in injury frequency was observed between the venues with the highest and lowest mean force reduction magnitudes.

CONCLUSIONS

Professional dancers can be required to perform on floors that may be inadequate for safe dance practice. Intra-floor force reduction variability may have a stronger association with injury risk than mean floor force reduction magnitude.

The virtuoso foot

The foot and ankle are prone to injury in the performing arts population, not least amongst dancers who require extreme ranges of movement in this area. This is a complex anatomical area which can be vulnerable to wide array of injuries. Many of these injuries stem from the dancer's posture, technique and environmental factors such as footwear and flooring; therefore, a thorough understanding of these by the clinician is important to ensure full rehabilitation and to prevent recurrence. This article presents an overview of the most common injuries seen in the dancer population and explores the underlying postural, technical and environmental factors that need to be addressed for full recovery.

Mechanics of Jazz Shoes and Their Effect on Pointing in Child Dancers

There has been little scientific investigation of the impact of dance shoes on foot motion or dance injuries. The pointed (plantar-flexed) foot is a fundamental component of both the technical requirements and the traditional aesthetic of ballet and jazz dancing. The aims of this study were to quantify the externally observed angle of plantar flexion in various jazz shoes compared with barefoot and to compare the sagittal plane bending stiffness of the various jazz shoes. Sixteen female recreational child dancers were recruited for 3D motion analysis of active plantar flexion. The jazz shoes tested were a split-sole jazz shoe, full-sole jazz shoe, and jazz sneaker. A shoe dynamometer measured the stiffness of the jazz shoes. The shoes had a significant effect on ankle plantar flexion. All jazz shoes significantly restricted the midfoot plantar flexion angle compared with the barefoot condition. The split-sole jazz shoe demonstrated the least restriction, whereas the full-sole jazz shoe the most midfoot restriction. A small restriction in metartarsophalangeal plantar flexion and a greater restriction at the midfoot joint were demonstrated when wearing stiff jazz shoes. These restrictions will decrease the aesthetic of the pointed foot, may encourage incorrect muscle activation, and have an impact on dance performance.

Evaluation of movements of lower limbs in non-professional ballet dancers: hip abduction and flexion

Background

The literature indicated that the majority of professional ballet dancers present static and active dynamic range of motion difference between left and right lower limbs, however, no previous study focused this difference in non-professional ballet dancers. In this study we aimed to evaluate active movements of the hip in non-professional classical dancers.

Methods

We evaluated 10 non professional ballet dancers (16-23 years old). We measured the active range of motion and flexibility through Well Banks. We compared active range of motion between left and right sides (hip flexion and abduction) and performed correlation between active movements and flexibility.

Results

There was a small difference between the right and left sides of the hip in relation to the movements of flexion and abduction, which suggest the dominant side of the subjects, however, there was no statistical significance. Bank of Wells test revealed statistical difference only between the 1^st and the 3^rd measurement. There was no correlation between the movements of the hip (abduction and flexion, right and left sides) with the three test measurements of the bank of Wells.

Conclusion

There is no imbalance between the sides of the hip with respect to active abduction and flexion movements in non-professional ballet dancers.

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.

Comparison of postural stability between injured and uninjured ballet dancers

BACKGROUND

Ballet movements require a limited base of support; thus, ballet dancers require a high level of postural control. However, postural stability in ballet dancers is still unclear and needs to be understood.

PURPOSE

To evaluate ballet dancers' postural stability in performing single-leg standing, the en pointe task, and the first and fifth positions and to determine differences in task performance among healthy nondancers, healthy dancers, and dancers with ankle sprains.

STUDY DESIGN

Controlled laboratory study.

METHODS

Injured dancers, uninjured dancers, and nondancers were recruited for this study (N = 33 age-matched participants; n= 11 per group). The tasks tested were single-leg standing with eyes open and closed, first position, fifth position, and en pointe. Center of pressure parameters were calculated from the ground-reaction force collected with 1 force plate. Analysis of variance was used to assess the differences of center of pressure parameters among 3 groups in single-leg standing; independent t test was used to examine the differences of center of pressure parameters between injured and uninjured dancers.

RESULTS

During single-leg standing, injured dancers had significantly greater maximum displacement in the medial-lateral direction and total trajectory of center of pressure, compared with the uninjured dancers and nondancers. During the first and fifth positions, the injured dancers demonstrated significantly greater standard deviation of center of pressure position in the medial-lateral and anterior-posterior directions, compared with the uninjured dancers. During en pointe, the injured dancers had significantly greater maximum displacement in the medial-lateral direction and the anterior-posterior direction, compared with the uninjured dancers.

CONCLUSION

The injured and uninjured dancers demonstrated differences in postural stability in the medial-lateral direction during single-leg standing and the ballet postures. Although the injured dancers received ballet training, their postural stability may still be inferior to that of the nondancers.

CLINICAL RELEVANCE

This study is a first step in understanding that injured ballet dancers do not have the same postural stability as uninjured dancers and that it is even inferior to that of nondancers, which is important to understand for further study on rehabilitation. The future development of effective balance training programs for ballet dancers with ankle injuries should emphasize improvements in medial-lateral directional balance.

Dance medicine of the foot and ankle: a review

All forms of dance are highly demanding activities, with a lifetime injury incidence of up to 90%. Most dance types are stressful, particularly on the dancer's forefoot, but certainly there is no area of the foot or ankle that is exempt from potential injury. Dancers often have unusual difficulties related to the dynamic biomechanical forces required by their individual dance form. A thorough understanding of these movements guides the physician to the cause of the injury, particularly in understanding specific overuse injuries. This article discusses biomechanics of the foot and the imaging and treatment of dance-related injuries.

Musculoskeletal injuries and pain in dancers: a systematic review

OBJECTIVE

To assemble and synthesize the best evidence on the epidemiology, diagnosis, prognosis, treatment, and prevention of musculoskeletal injuries and pain in dancers.

DATA SOURCES

Medline, CINAHL, PsycINFO, Embase, and other electronic databases were searched from 1966 to 2004 using key words such as dance, dancer, dancing, athletic injuries, occupational injuries, sprains and strains, and musculoskeletal diseases. In addition, the reference lists of relevant studies were examined, specialized journals were hand-searched, and the websites of major dance associations were scanned for relevant information.

STUDY SELECTION

Citations were screened for relevance using a priori criteria, and relevant studies were critically reviewed for scientific merit by the best evidence synthesis method. After 1865 abstracts were screened, 103 articles were reviewed, and 32 (31%) of these were accepted as scientifically admissible (representing 29 unique studies).

DATA EXTRACTION

Data from accepted studies were abstracted into evidence tables relating to the prevalence and associated factors, incidence and risk factors, diagnosis, treatment, economic costs, and prevention of musculoskeletal injuries and pain in dancers.

DATA SYNTHESIS

The scientifically admissible studies consisted of 15 (52%) cohort studies, 13 (45%) cross-sectional studies, and 1 (3%) validation study of a diagnostic assessment tool. There is a high prevalence and incidence of lower extremity and back injuries, with soft tissue and overuse injuries predominating. For example, lifetime prevalence estimates for injury in professional ballet dancers ranged between 40% and 84%, while the point prevalence of minor injury in a diverse group of university and professional ballet and modern dancers was 74%. Several potential risk factors for injury are suggested by the literature, but conclusive evidence for any of these is lacking. There is preliminary evidence that comprehensive injury prevention and management strategies may help decrease the incidence of future injury.

CONCLUSIONS

The dance medicine literature is young and heterogeneous, limiting our ability to draw consistent conclusions. Nonetheless, the best available evidence suggests that musculoskeletal injury is an important health issue for dancers at all skill levels. Better quality research is needed in this specialized area. Future research would benefit from clear and relevant research questions being addressed with appropriate study designs, use of conceptually valid and clinically meaningful case definitions of injury and pain, and better reporting of studies in line with current scientific standards.