Publications

BACKGROUND: Sports concussion receives heavy attention from researchers. Conversely, research devoted to performing arts concussion is scant, despite a variety of head injury opportunities in artistic endeavors and environments. Circus is a high-energy, high-velocity performing art for which minimal concussion research is available.

PURPOSE: Assess via medical records the 10-year concussion incidence in Cirque du Soleil (CdS) performers and the variables surrounding their concussions.

STUDY DESIGN: Descriptive epidemiology.

LEVEL OF EVIDENCE: Level 5.

METHODS: Data were extracted from CdS performers' medical records for 2010 to 2019: sex, age at injury, performance type, artistic discipline, mechanism of injury, performance context, and time-loss from full participation. Yearly artist-exposures for all CdS artists were identified. Data were analyzed for both resident and touring shows.

RESULTS: Over 10 years there were 2,733,073 exposures, with 354 concussions sustained among 296 performers. Acrobats were the most commonly concussed (82.8% of all concussions). There were 1.30 concussions per 10,000 artist-exposures. Repeat concussions accounted for 58 concussions (16.4%). Full return to performance occurred at a mean of 35.5 ± 100.3 days. The highest rate of concussions was in 2019 (1.93 per 10,000 artist-exposures); 2010 had the lowest (0.86 per 10,000 artist-exposures). More concussions occurred during performances than training sessions; nearly half (170 of 354) occurred during the first of 2 shows presented nightly. There was no significant difference in overall incidence between resident and touring performers. The most frequent concussion mechanisms were impact with apparatus/equipment (113 of 354) or with another artist (106 of 354).

CONCLUSION: The concussion incidence of CdS artists is noteworthy compared with sports concussions. Acrobats sustained the most concussions. Concussions occurred more frequently during performances than during training.

CLINICAL RELEVANCE: These new data on performing arts concussions highlight the prevalence and incidence of concussions in circus performers for healthcare professionals who care for them.

BACKGROUND: Mild traumatic brain injuries receive voluminous attention in the research literature, but this is confined almost entirely to sports and military contexts. As an occupation, performing stunts in film, television, and entertainment places the head at high risk of repetitive impact and whiplash, but stunt performers do not enjoy the same level of healthcare supervision and access as that provided to sports participants. Therefore, the aim of this study was to evaluate stunt performers' qualitative perceptions of reporting and management of head trauma in their industry.

METHODS: After giving their informed consent, 87 motion picture and television stunt performers responded to a query about their views of ways to improve how stunt performers' occupational head trauma-specifically head impacts and head whips that could cause a concussion-are reported and managed. We analyzed their responses via content and thematic analyses. Two researchers independently marked and categorized key words, phrases, and texts to identify codes that described participants' comments. They then revised, discussed, and resolved coding discrepancies through consensus to establish inter-coder reliability. Next, we identified thematic patterns that described participants' understanding of the stunt performer industry and what must change to facilitate reporting of head trauma. We derived themes from data that occurred multiple times, both within and across short answer responses.

RESULTS: We identified three primary themes cited by the stunt performers as needs in their industry: (1) Need to Reduce the Stigma of Reporting a Stunt-Related Injury, (2) Need to Eliminate the "Cowboy Culture," and (3) Need to Improve the Quality of the Work Environment.

CONCLUSIONS: Stunt performers are crucial members of a global entertainment industry valued at approximately US$100 billion annually. A large segment of the world's population consumes their work in motion pictures, television, and live entertainment. When they are given an anonymous opportunity to speak, stunt performers offer insight into and recommendations for industry changes-primarily cultural and educational in nature-that could improve their physical and mental health, career longevity, and employability when they are confronted with head trauma.

OBJECTIVES: The aims of the study were to assess prevalence and management of head impacts in stunt performers and to evaluate performers' quality of life and ability to work after head injury.

METHODS: Stunt performers completed an online survey about head impacts/head whips history, diagnosed concussions, reasons for not reporting injuries, health care sought after head impacts, attitudes toward on-set concussion management, perceived ability to work as a stunt performer, and health-related quality of life.

RESULTS: One hundred seventy-three performers (80%) indicated at least one head impact/head whip during their stunt career. Of these, 86% exhibited concussion-like symptoms and 38% received one or more concussion diagnoses. Sixty-five percent continued working with concussion-like symptoms. Short Form-12 mental component scores were suggestive of depression in 42%.

CONCLUSIONS: Concussion seems to be a serious occupational health issue in stunt performers. We suggest that concussion management, risk reduction, and education should be addressed in this community.

Foot injuries occur frequently in dancers, and researchers have investigated different protective measures to reduce their incidence. Research has primarily focused on ballet, but foot injuries also are common in modern and contemporary dance where footwear is not worn. While padded dance socks are a potential solution, the extent to which they provide force reduction for the feet is unknown.<br/> Purpose: This study investigates the extent to which padded dance support socks can reduce force on the foot during a dance sequence and when landing from a sauté jump.<br/> Methods: Twenty-one injury-free dancers (2 M, 19 F; age: 21.5 ± 6.7 years; height: 165.5 ± 6.1 cm; mass: 68.6 ± 15.0 kg) volunteered for this randomized, cross-over design study. Participants per- formed a 40-second modern dance sequence and a sauté jump landing under two conditions: wearing Apolla Performance Shock™ dance socks (DS) and with bare feet (BF). During these activities, 1.0 cm diameter circular force transducers were affixed under the first metatarsophalangeal joint and under the center of the heel. The sensors wirelessly recorded peak toe force, peak heel force, mean toe force, and mean heel force during dancing. A force platform measured vertical ground reaction force (VGRF) and time to peak VGRF, while the foot sensors measured peak toe force and peak heel force, during the jump landings. A Noraxon MR3.12 biomechanics system synchronized and recorded the data. All force data were normalized to body weight (BW). Dependent samples t-tests were used to assess pairwise differences in these measures between the DS and BF conditions. Alpha was set at p < 0.05.<br/> Results: Mean and peak heel forces/BW when dancing with DS were significantly lower than during BF dancing (mean: p = 0.015; peak: p = 0.0004). Peak VGRF/BW when landing from the sauté jump with DS was significantly lower compared with landing in BF (p = 0.035). All other variables were not significantly different between conditions, but all DS force values were lower than BF.<br/> Conclusions: We offer evidence that padded dance socks may reduce foot forces dancers commonly encounter during modern dance. The trends we recorded require further study to assess the extent to which the socks exhibit beneficial effects when considering both the many hours dancers train and the cumulative effects of impacts sustained by their feet.

Dancers and other performing artists are subject to head impacts that result in concussion-like symptoms. In spite of this, performing arts do not have access to the continual, focused emphasis on the diagnosis, management, and prevention of concussions that is commonplace in sports. Performing arts present a unique environment in which concussions occur and must be managed. This article outlines what is known about performing arts concussions, describes mechanisms of head impacts sustained by participants in dance and the related artforms of theater, circus, and film and television stunts, and offers concussion management guidelines for these artistic fields.

The ankles of ballet dancers are routinely under heavy loading that may lead to osteoarthritic changes. It would be clinically useful to identify such pathology as early as possible in a dancer's career. Therefore, the purpose of this study was to compare quantitative measurements in magnetic resonance (MR) images of the talocrural and talonavicular joints in ballet dancers and healthy non-dancers for use in formulating prediction of chronic injury and degenerative joint disease in these locations. Quantitative measurements in MR images of the talocrural and talonavicular joints were compared in 10 female ballet dancers, 10 healthy female non-dancers, and nine male ballet dancers. Fat-suppressed density-weighted proton, T1rho, and T2 mapping images were acquired with a 3.0 T MR scanner. Medial and lateral subchondral bone distance between the tibia and talus (MSBD and LSBD), axial navicular-talus axis angle (ANT angle), sagittal talar neck angle against the posterior talocalcaneal joint (TN angle), and curvature of navicular surface at the talonavicular joint were measured on sagittal images. The medial subchondral bone distance was found to be significantly larger in female dancers than female non-dancers (4.05 mm vs. 2.75 mm, p < 0.05), whereas there were no significant differences in LSBD (2.63 mm vs. 2.63 mm, p = 0.87). Axial navicular talus angles in female dancers were significantly larger than those in female non-dancers (38.9° vs. 24.3°, p < 0.05). There was a tendency for the TN angle to be smaller and navicular curvature (NC) to be larger in female dancers compared to female non-dancers, though the differences were not significant (TN angle: 16.6° vs. 22.3°, p = 0.09, and NC: 0.186 vs. 0.165, p = 0.28). There were no significant differences in T1rho or T2 values of talonavicular joint cartilage. These results show that the bony anatomy of dancers' ankles may adapt to the stresses placed on them by ballet.

OBJECTIVES: (1) To measure sound exposures of marching band and non-marching band students during a football game, (2) to compare these to sound level dose limits set by NIOSH, and (3) to assess the perceptions of marching band students about their hearing health risk from loud sound exposure and their use of hearing protection devices (HPDs).

METHODS: Personal noise dosimetry was completed on six marching band members and the band director during rehearsals and performances. Dosimetry measurements for two audience members were collected during the performances. Noise dose values were calculated using NIOSH criteria. One hundred twenty-three marching band members responded to a questionnaire analyzing perceptions of loud music exposure, the associated hearing health risks, and preventive behavior.

RESULTS: Noise dose values exceeded the NIOSH recommended limits among all six marching band members during rehearsals and performances. Higher sound levels were recorded during performances compared to rehearsals. The audience members were not exposed to hazardous levels. Most marching band members reported low concern for health effects from high sound exposure and minimal use of HPDs.

CONCLUSION: High sound exposure and low concern regarding hearing health among marching band members reflect the need for comprehensive hearing conservation programs for this population.

BACKGROUND: Since ballet dancers begin their training before skeletal maturity, accurate and non-invasive identification of cartilage diseases is clinically important. Angle-dependent analysis of T1rho and T2 sequences can be useful for quantification of the composition of cartilage.

PURPOSE: To investigate the angle-dependent T1rho and T2 profiles of ankle cartilage in non-dancers and dancers.

MATERIAL AND METHODS: Ten female non-dancers, ten female dancers, and 9 male dancers were evaluated using T1rho and T2 mapping sequences. Manual segmentation of talar and tibial cartilage on these images was performed by two radiologists. Inter- and intra-rater reliabilities were calculated using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Mean thickness and volume of cartilage were estimated. Angle-dependent relaxation time profiles of talar and tibial cartilage were created.

RESULTS: ICCs of the number of segmented pixels were poor to excellent. Bland-Altman plots indicated that differences were associated with segment sizes. Segmented cartilage on T1rho demonstrated larger thickness and volume than those on T2 in all populations. Male dancers showed larger cartilage thickness and volume than female dancers and non-dancers. Each cartilage demonstrated angular-dependent T1rho and T2 profiles. Minimal T1rho and T2 values were observed at approximately 180°-200°; higher values were seen at the angle closer to the magic angle. Minimal T2 value of talar cartilage of dancers was larger than that of non-dancers.

CONCLUSION: In this small cohort study, regional and sex variations of ankle cartilage T1rho and T2 values in dancers and non-dancers were demonstrated using an angle-dependent approach.

BACKGROUND: Music-induced hearing disorders are known to result from exposure to excessive levels of music of different genres. Marching band music, with its heavy emphasis on brass and percussion, is one type that is a likely contributor to music-induced hearing disorders, although specific data on sound pressure levels of marching bands have not been widely studied. Furthermore, if marching band music does lead to music-induced hearing disorders, the musicians may not be the only individuals at risk. Support personnel such as directors, equipment managers, and performing arts healthcare providers may also be exposed to potentially damaging sound pressures. Thus, we sought to explore to what degree healthcare providers receive sound dosages above recommended limits during their work with a marching band.

PURPOSE: The purpose of this study was to determine the sound exposure of healthcare professionals (specifically, athletic trainers [ATs]) who provide on-site care to a large, well-known university marching band. We hypothesized that sound pressure levels to which these individuals were exposed would exceed the National Institute for Occupational Safety and Health (NIOSH) daily percentage allowance.

RESEARCH DESIGN: Descriptive observational study.

STUDY SAMPLE: Eight ATs working with a well-known American university marching band volunteered to wear noise dosimeters.

DATA COLLECTION AND ANALYSIS: During the marching band season, ATs wore an Etymotic ER-200D dosimeter whenever working with the band at outdoor rehearsals, indoor field house rehearsals, and outdoor performances. The dosimeters recorded dose percent exposure, equivalent continuous sound levels in A-weighted decibels, and duration of exposure. For comparison, a dosimeter also was worn by an AT working in the university's performing arts medicine clinic. Participants did not alter their typical duties during any data collection sessions. Sound data were collected with the dosimeters set at the NIOSH standards of 85 dBA threshold and 3 dBA exchange rate; the NIOSH 100% daily dose is an exposure to 85 dBA over 8 h. Dose data for each session were converted to a standardized dose intensity by dividing the dose percentage by the duration of the exposure and setting the NIOSH standard as a factor of 1.0. This allowed convenient relative comparisons of dose percentages of vastly different exposure durations. Analysis of variance examined relationships of noise exposures among the venues; post hoc testing was used to assess pairwise differences.

RESULTS: As hypothesized, ATs were exposed to high sound pressure levels and dose percentages greatly exceeding those recommended by NIOSH. Higher sound levels were recorded in performance venues compared with rehearsal venues. In addition to the band music, crowd noise and public address systems contribute to high sound levels at performances.

CONCLUSIONS: Our results suggest that healthcare providers working with marching bands are exposed to dangerous levels of sound during performances. This is especially true at venues such as football stadiums, where crowd noise and public address systems add to sound pressure. A hearing conservation program, including protection, should be required for all healthcare staff who work with marching bands. Moreover, our results should inform hearing conservation practices for marching musicians, directors, and support personnel.

OBJECTIVE: Determine the history of occupational head impacts, concussion symptoms, and concussion management in theater personnel.

METHODS: Personnel working in theater environments completed a survey about head impacts that occurred in theater activities and how they were managed.

RESULTS: Lifetime prevalence of sustaining at least one theater-related head impact was 67%. Thirty-nine percent of respondents reported more than five lifetime head impacts; 77% reported three or more. Of those who struck their head, 70% experienced concussion-related symptoms, but continued participating. Nearly half of those did not report the incident. Twenty-eight percent of those diagnosed with a concussion by a healthcare provider were not given recommended care.

CONCLUSIONS: Theater personnel are likely to sustain several occupational head impacts. They appear hesitant to report possible concussions and generally do not access definitive, evidence-based healthcare for head injuries.