Comparing Harmful Behaviors Among Dancers According to Sexual Orientation and Gender Identity Utilizing the RISQ.

INTRODUCTION: There is a dearth of information about whether lesbian, gay, bisexual, transgender, queer/questioning (LGBTQ+) dancers, who often experience increased psychosocial risk factors, are at increased risk of engaging in harmful behaviors compared to their heterosexual cisgender counterparts. This study explores harmful behaviors dancers engage in according to their self-reported sexual orientation and gender identity (SOGI), utilizing the validated Risky, Impulsive, and Self-Destructive Behavior Questionnaire (RISQ). METHODS: Three hundred sixty-four dancers from 7 elite dance entities in New York were contacted by e-mail to participate in the study. Sixty-six participants completed the study through a virtual questionnaire. Chi-square, ANOVA and independent t-test were utilized to assess statistical differences among RISQ outcomes in 4 SOGI groups: Cisgender Heterosexual Female (n = 20); Cisgender Heterosexual Male (n = 7); LGBTQ+ Female (n = 19); and LGBTQ+ Male (n = 20). RESULTS: Chi-square comparing SOGI group frequency of participation within each of the RISQ behaviors revealed statistically significant difference with: difficulty stopping eating (P = .05); gambling illegally (P = .036); betting on sports, horses, or other animals (P = .036); buying expensive items that cannot be afforded at the spur of the moment (P = .019); and drinking 5 or more alcoholic drinks in 3 hours or less (P = .013). Between-group frequency comparison through ANOVA and independent t-test revealed: the LGBTQ+ Male group were 92% more likely to have unprotected sex with someone they just met or did not know well (P < .001) and 83% more likely to use hallucinogens, LSD, or mushrooms (P = .018); the LGBTQ+ Female and LGBTQ+ Male groups were 4.4 times more likely to buy drugs (P = .01) and 4.88 times more likely to think about killing themselves (P = .023); and both male groups were 12.8 times more likely to steal money (P = .006). CONCLUSIONS: This study found significant difference in RISQ scores based on a dancer's SOGI. Harmful behaviors should be taken into consideration when working to improve dancer patient outcomes and quality of life.

Motion of the multi-segmented spine in elite dancers during passé and arabesque.

BACKGROUND: The spinal biomechanics of dance tasks have received little study and no studies have used a multi-segmented spinal model. Knowledge of how the segments of the spine move may be useful to the dance clinician and dance educator. RESEARCH QUESTION: What is the direction and amount of motion of the primary segments of the spine in elite dancers during an arabesque and a passé? METHODS: This observational study examined 59 elite dancers performing an arabesque and a passé using a three-dimensional motion analysis system with the trunk divided into a series of five segments: pelvis, lower lumbar, upper lumbar, lower thoracic and upper thoracic spine. RESULTS: For the arabesque, all spinal segments moved in the same direction within each plane and the majority of total spinal motion occurred in the thoracic spine. Thoracic segments were at or near end range position at completion of the arabesque. For the passé, the spinal segments moved in different directions within each plane and the majority of total spinal motion occurred in the lumbar spine. SIGNIFICANCE: Dance clinicians and dance educators may benefit from the knowledge that thoracic hypomobility in any plane may limit arabesque performance and that attempts to instruct dancers to achieve a position of passé without flexion of the lumbar spine may be a valid aesthetic ideal but also an unrealistic functional expectation.

Multi-segment spine range of motion in dancers with and without recent low back pain.

BACKGROUND: Altered spine kinematics are a common in people with LBP. This may be especially true for populations such as dancers, who are required to perform repetitive movements of the spine, although this remains unclear. RESEARCH QUESTION: Do dancers with recent LBP display altered spine kinematics compared to their asymptomatic counterparts? METHODS: A cross-sectional study of multi-segment spine kinematics was performed. Forty-seven pre-professional and professional female dancers either with LBP in the past two months (n = 26) or no LBP in the past 12 months (n = 21) participated. Range of motion (ROM) during standing side bending, seated rotation, and walking gait were compared. RESULTS: Female dancers with LBP displayed reduced upper lumbar transverse plane ROM in seated rotation (Effect Size (ES)= -0.61, 95% Confidence Interval (CI): -1.20, 0.02, p = 0.04), as well as reduced lower lumbar transverse plane ROM (ES=-0.65, 95% CI: -1.24, -0.06, p = 0.03) in gait. However, there was increased lower thoracic transverse plane ROM (ES = 0.62, 95% CI: 0.04, 1.21, p = 0.04) during gait. No differences in the frontal plane were observed. SIGNIFICANCE: Altered transverse plane spine kinematics were evident in dancers with recent LBP for select segments and tasks. This may reflect a protective movement strategy. However, as the effect sizes of observed differences were moderate, and the total number of differences between groups was small, collectively, it seems only subtle differences in spine kinematics differentiate dancers with LBP to dancers without.

Comparison of lower limb stiffness between male and female dancers and athletes during drop jump landings.

Repetition of jumps in dance and sport training poses a potential injury risk; however, non-contact landing injuries are more common in athletes than dancers. This study aimed to compare the lower limb stiffness characteristics of dancers and athletes during drop landings to investigate possible mechanisms of impact-related injuries. Kinematics and kinetics were recorded as 39 elite modern and ballet dancers (19 men and 20 women) and 40 college-level team sport athletes (20 men and 20 women) performed single-legged drop landings from a 30-cm platform. Vertical leg stiffness and joint stiffness of the hip, knee, and ankle were calculated using a spring-mass model. Stiffness data, joint kinematics, and moments were compared with a group-by-sex 2-way analysis of variance. Multiple linear regression was used to assess the relative contribution of hip and knee and ankle joint stiffness to variance in overall vertical leg stiffness for dancers and athletes. Dancers had lower leg (P < 0.001), knee joint (P = 0.034), and ankle joint stiffness (P = 0.043) than athletes. This was facilitated by lower knee joint moments (P = 0.012) and greater knee (P = 0.029) and ankle joint (P = 0.048) range of motion in dancers. Males had higher leg (P < 0.001) and ankle joint stiffness (P < 0.001) than females. This occurred through lower ankle range of motion (P < 0.001) and greater ankle moment (P = 0.022) compared to females. Male and female dancers demonstrated reduced lower limb stiffness compared to athletes, indicating a more pliable landing technique. Dance training techniques could potentially inform approaches to injury prevention in athletes.

A Retrospective Assessment of Return to Function in Dance After Physical Therapy for Common Dance Injuries.

An injury that causes a dancer to take time away from training or performance can be career ending, and thus it is important for dancers to have accurate expectations when considering treatment options. Thus far, few studies have reported functional outcomes after injury in dancers, which may be different than for the general athletic population. Therefore, our study sought to determine functional outcomes in dancers after operative and non-operative treatment for common dance injuries. Our outcome measures included a subjective assessment of the degree to which a dancer had returned to his or her previous level of dance, the SF-12 survey, and the WHO functional outcome scale modified for dance. We also compared these as outcome measurement tools for return to full function in dance. Secondarily, we sought to assess factors that may have contributed to poorer functional outcomes. We reviewed the charts of 675 dancers seen at our physical therapy facilities between 2006 and 2010 and identified 416 adult dancers who had experienced a dance-related injury that we categorized as "common," based on surveys of injuries among dancers (with back injuries excluded). One hundred and sixty-four dancers completed a tele- phone survey about their recovery after injury. Descriptive statistics, correlation, and linear regression were then used to identify factors associated with poor functional outcomes. Sixty-three percent of the participants had a full return to their pre-injury level. No variables were found to be significantly correlated (p < 0.05) with poorer outcomes by linear re- gression. However, there was a trend to- ward better outcomes when dancers were younger, their injuries were not chronic, and their recovery was not limited by fear. The three measurement tools were all highly correlated with one another (p = 0.000) and found to be useful determinants of functional return to dance. Given that there were few strongly correlated outcome factors, we concluded that poorer functional outcomes in dance resulted from a combination of many factors, including those of a psychosocial nature. We believe these results can be used to better advise dancers who are considering treatment options, provide better estimates of possible limitations and time needed to return to dance, and potentially promote easier recoveries and better functional outcomes.

Concussion Knowledge and Behaviors in a Sample of the Dance Community.

Despite recent improvements in their concussion knowledge, athletes still demonstrate risky concussion behaviors (e.g., playing while concussed or not reporting a concussion). Little has been published about dancers' concussion knowledge and behaviors, but research in dance contending with questions about injury in general has found that dancers often avoid physician consults and ignore the signs of injury. In the present study, an IRB approved anonymous online survey, it was hypothesized that dancers would demonstrate concussion knowledge deficits, fail to report concussions, and have difficulty adhering to management guidelines. In addition, it was hypothesized that dancers in companies or schools with an onsite health care practitioner present would demonstrate improved concussion knowledge and safer concussion behaviors compared with those that do not have onsite health care. Concussion knowledge and behavior questions were modified for a dance sample based on validated sports-specific tools developed by other investigators. One hundred fifty-three subjects were recruited to complete the survey from an urban orthopaedic clinic specializing in dance medicine and via Facebook, email, and newsletter announcements. Dancers in this sample had good foundational knowledge of concussion; however, this knowledge did not correlate with safe, self-reported concussion care behaviors. Future research should focus on determination of dance-specific barriers to practicing safe behaviors and seeking care for concussive injury, as well as further identifying dance concussion epidemiology and outcomes.

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.

Comparison of landing biomechanics between male and female dancers and athletes, part 1: Influence of sex on risk of anterior cruciate ligament injury.

BACKGROUND: The incidence of anterior cruciate ligament (ACL) injuries among dancers is much lower than among team sport athletes, and no clear disparity between sexes has been reported in the dance population. Although numerous studies have observed differences in landing biomechanics of the lower extremity between male and female team sport athletes, there is currently little research examining the landing biomechanics of male and female dancers and none comparing athletes to dancers. Comparing the landing biomechanics within these populations may help explain the lower overall ACL injury rates and lack of sex disparity. HYPOTHESIS: The purpose was to compare the effects of sex and group (dancer vs team sport athlete) on single-legged drop-landing biomechanics. The primary hypothesis was that female dancers would perform a drop-landing task without demonstrating typical sex-related risk factors associated with ACL injuries. A secondary hypothesis was that female team sport athletes would display typical ACL risk factors during the same task. 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) performed single-legged drop landings from a 30-cm platform. Joint kinematics and kinetics were compared between groups and sexes with a group-by-sex multivariate analysis of variance (MANOVA) followed by pairwise t tests. RESULTS: Dancers of both sexes and male team sport athletes landed similarly in terms of frontal-plane knee alignment, whereas female team sport athletes landed with a significantly greater peak knee valgus (P = .007). Female dancers were found to have a lower hip adduction torque than those of the other 3 groups (P = .003). Dancers (male and female) exhibited a lower trunk side flexion (P = .002) and lower trunk forward flexion (P = .032) compared with team sport athletes. CONCLUSION: In executing a 30-cm drop landing, female team sport athletes displayed a greater knee valgus than did the other 3 groups. Dancers exhibited better trunk stability than did athletes. CLINICAL RELEVANCE: These biomechanical findings may provide insight into the cause of the epidemiological differences in ACL injuries between dancers and athletes and the lack of a sex disparity within dancers.

What is known about the effect of fatigue on injury occurrence among dancers?

Fatigue is often thought of as any transient exercise-induced reduction of work capacity. In fact, it is a complex phenomenon caused by overlapping and interacting peripheral and central mechanisms. There is a known relationship between fatigue, diminished performance, and injury. This paper reviews what is currently known about fatigue in the current literature.

The effects of floor incline on lower extremity biomechanics during unilateral landing from a jump in dancers.

Retrospective studies have suggested that dancers performing on inclined ("raked") stages have increased injury risk. One study suggests that biomechanical differences exist between flat and inclined surfaces during bilateral landings; however, no studies have examined whether such differences exist during unilateral landings. In addition, little is known regarding potential gender differences in landing mechanics of dancers. Professional dancers (N = 41; 14 male, 27 female) performed unilateral drop jumps from a 30 cm platform onto flat and inclined surfaces while extremity joint angles and moments were identified and analyzed. There were significant joint angle and moment effects due to the inclined flooring. Women had significantly decreased peak ankle dorsiflexion and hip adduction moment compared with men. Findings of the current study suggest that unilateral landings on inclined stages create measurable changes in lower extremity biomechanical variables. These findings provide a preliminary biomechanical rationale for differences in injury rates found in observational studies of raked stages.

Assessing and Reporting Dancer Capacities, Risk Factors, and Injuries: Recommendations from the IADMS Standard Measures Consensus Initiative.

This technical report of the Standard Measures Consensus Initiative of the International Association for Dance Medicine and Science (IADMS) describes the results of the committee's multi-year effort to synthesize information regarding the tests and measures used in dance-related research, protocols for reporting injuries, and appropriate use of available technologies to aid in standardizing such matters. Specific recommendations are presented, with accompanying rationales, to facilitate consensus among members of the dance medicine and science community. An Executive Summary of this Technical Report, which contains implementation strategies and appendices, should soon be available on the IADMS website.

Time to stability differences between male and female dancers after landing from a jump on flat and inclined floors.

OBJECTIVE: To determine the effect of gender and inclined floor on time to stability (TTS) after landing from a vertical jump. DESIGN: This study used a repeated measures design with male and female professional dancers landing on a flat and 4 inclined floors. A repeated measures univariate analysis of variance (gender × floor) was performed on TTS in the anterior-posterior and medial-lateral directions. SETTING: Biomechanics laboratory. PARTICIPANTS: Twenty-three female and 13 male professional dancers. INDEPENDENT VARIABLES: Gender and floor inclination (flat, posterior, anterior, lateral, and medial). MAIN OUTCOME MEASURES: Time to stability in the anterior-posterior and medial-lateral directions after landing from a vertical jump. RESULTS: Female dancers exhibited longer TTS in both directions (P ≤ 0.05). Floor inclination or the interaction of gender × floor did not have an effect on TTS (P > 0.3). CONCLUSIONS: Female dancers exhibited longer TTS after landing from a vertical jump compared with their male counterparts. This balance difference may be a factor related to the higher rate of ankle sprain among female dancers. Additionally, professional dancers exhibited similar TTS when landing on flat and inclined floors.

Functional criteria for assessing pointe-readiness.

The most popular criterion cited in the dance literature for advancement to pointe work is attainment of the chronological age of 12 years. However, dancers at this age vary greatly in terms of musculoskeletal maturity and motor skill development. The purpose of this study was to investigate whether objective, functional tests could be used in conjunction with dance teacher expertise to determine pointe-readiness. It was hypothesized that dynamic tests of motor control can better indicate pointe-readiness than chronological age alone or in combination with static musculoskeletal measurements. Thirty-seven pre-pointe students from two professional ballet schools were tested for muscular strength, ankle joint range of motion, single leg standing balance, dynamic alignment, and turning skill. In addition, the participating students' ballet teachers independently graded each student on her readiness to begin dancing en pointe. Performance on three functional tests (the Airplane test, Sauté test, and Topple test) was closely associated with teacher subjective rating for pointe-readiness. It is concluded that these tests may be more useful for gauging acquisition of the skills required for safe and successful performance than the traditionally accepted indicators of chronological age, years of dance training, and ankle joint range of motion.

Perspectives on dance science rehabilitation understanding whole body mechanics and four key principles of motor control as a basis for healthy movement.

This article reviews selected issues of importance in the evaluation, treatment, and reconditioning of dancers during and following injury and offers some insights on injury prevention. The athletic training practice domains of prevention, clinical evaluation and diagnosis, treatment, and rehabilitation and reconditioning within the context of dance medicine are the general focus. In particular, issues relating to the rehabilitation of dancers are presented as they reflect the reasonable, objective practices of the health care profession.

Comparison of landing biomechanics between male and female professional dancers.

BACKGROUND: The incidence of anterior cruciate ligament injuries among dancers is much lower than that among team sport athletes and no clear gender disparity has been reported in the dance population. Although numerous studies have observed differences in lower extremity landing biomechanics between male and female athletes, there is currently little research examining the landing biomechanics of male and female dancers. Comparing landing biomechanics within this population may help explain the lower overall anterior cruciate ligament injury rates and the lack of gender disparity. HYPOTHESIS: Due to the fact that dancers receive jump-specific and balance-specific training from a very young age, we hypothesized that there would be no gender differences in drop-landing biomechanics in professional dancers. STUDY DESIGN: Controlled laboratory study. METHODS: Kinematics and ground-reaction forces were recorded as 33 professional modern and ballet dancers (12 men and 21 women) performed single-legged drop landings from a 30-cm platform. Joint kinematics and kinetics were compared between genders. RESULTS: No gender differences in joint kinematics or kinetics were found during landings (multivariate analysis of variance: P = .490 and P = .175, respectively). A significant relationship was found between the age at which the dancers began training and the peak hip adduction angle during landing (r = .358, P = .041). CONCLUSION: In executing a 30-cm drop landing, male and female dancers exhibited similar landing strategies and avoided landing patterns previously associated with increased injury rates. CLINICAL RELEVANCE: Commonly reported biomechanical differences between men and women, as well as the gender disparity among athletes in the incidence of ACL injuries, may be the result of inadequate experience in proper balance and landing technique rather than intrinsic gender factors. Beginning jump-specific and balance-specific training at an early age may counteract the potentially harmful adaptations in landing biomechanics observed in female athletes after maturity.

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.

Toe flexor forces in dancers and non-dancers.

Toe flexor force (hallux and second toe) was determined in the right and left feet of 24 dancers and 29 non-dancers (sitting and standing positions) using a commercially-available pressure sensor connected to a voltmeter. For the hallux and second toe combined (all trials combined), average toe flexor force was slightly greater for dancers than non-dancers (dancers, 7 +/- 4 N; non-dancers, 6 +/- 4 N; P<0.049). For dancers and non-dancers combined (all trials), the average toe flexor force of the hallux was more than twice that of the second toe (hallux, 9 +/- 4 N; 2nd toe, 4 +/- 1 N; P<0.0001); average toe flexor force was slightly greater in standing than sitting positions (standing, 7 +/- 4 N; sitting, 6 +/- 3 N; P<0.0001); and the average toe flexor force was slightly greater for the right than left foot (right, 7 +/- 4 N; left, 6 +/- 4 N; P<0.012). The average toe flexor force was greatest for the first repetition and slightly decreased for the second and third repetitions (first repetition, 7 +/- 4 N; second and third repetitions each, 6 +/- 4 N; P<0.0013). Toe flexor force measurement may potentially be applicable to clinical practice as a guide to rehabilitation after injury or as a screening parameter for readiness to advance dance or other athletic training, performance, or competition.