Is Training Load Associated with Symptoms of Overuse Injury in Dancers? A Prospective Observational Study

Systematic review of methods used to measure training load in dance

Dance is a popular physical activity. Increased dance training has been associated with an increased risk of injury. Given the established association between training load (TL) and injury in sport, knowledge of how TL is currently being measured in dance is critical. The objective of this study is to summarise published literature examining TL monitoring in dance settings. Six prominent databases (CINAHL, EMBASE, Medline, ProQuest, Scopus, SportDiscus) were searched and nine dance-specific journals were handsearched up to May 2022. Selected studies met inclusion criteria, where original TL data were collected from at least one dancer in a class, rehearsal and/or performance. Studies were excluded if TL was not captured in a dance class, rehearsal or performance. Two reviewers independently assessed each record for inclusion at title, abstract and full-text screening stages. Study quality was assessed using Joanna Briggs Institute Critical Appraisal Tool checklists for each study design. The 199 included studies reported on female dancers (61%), ballet genre (55%) and the professional level (31%). Dance hours were the most common tool used to measure TL (90%), followed by heart rate (20%), and portable metabolic systems (9%). The most common metric for each tool was mean weekly hours (n=381; median=9.5 hours, range=0.2-48.7 hours), mean heart rate (n=143) and mean oxygen consumption (n=93). Further research on TL is needed in dance, including a consensus on what tools and metrics are best suited for TL monitoring in dance.

Don't stop me now: A qualitative study of how Brazilian dancers and staff perceive injury and its prevention

OBJECTIVE

To investigate how Brazilian dancers and dance staff perceive and deal with injury and its prevention in professional and non-professional contexts.

DESIGN

Qualitative study.

SETTING

Semi-structured interviews conducted using an online platform.

PARTICIPANTS

Thirteen participants (8 women, 5 men) from four different dance styles (classical ballet, jazz, contemporary and urban): 6 dancers, 6 staff and 1 classified as both.

MAIN OUTCOME MEASURES

Interviews were recorded, transcribed and analyzed based on Grounded Theory principles using comparative data analysis.

RESULTS

The main themes and findings were: 1) Injury definition: Injury was defined and classified based on pain, structural damage and consequent limitations and restrictions. 2) Dealing with injury: Dancers' fear of having to stop dancing justifies different behaviours facing injury. 3) Injury factors: Overload and many personal and environmental factors were perceived as related to injury. 4) Injury prevention: it is linked with physical preparation and additional measures and influenced by communication, trust, experience, time, access to preventive programs, dancers' personalities and environmental factors. Responsibility for injury prevention should be shared by all stakeholders.

CONCLUSIONS

To improve injury prevention, we need to acknowledge the dancers' drive to keep dancing, consider the multiple factors that influence their behaviours, and develop education and self-efficacy to help them make better decisions to reduce the risk of injury.

Dance Exposure, Individual Characteristics, and Injury Risk over Five Seasons in a Professional Ballet Company

PURPOSE

This study aimed to describe the relationships between dance exposure, dancer characteristics, and injury risk across five seasons in a professional ballet company.

METHODS

Dance exposure time and clinician-reported time-loss and medical attention injury data were prospectively collected from 118 professional dancers of The Royal Ballet between 2015/2016 and 2019/2020. Cox proportional hazards and shared frailty models were fitted to overuse and traumatic injuries; individualized robust Z-scores for 7- and 28-d accumulated exposure, and week-to-week change in exposure, age, sex, company rank, and injury history were included as time-varying covariates.

RESULTS

Across 381,710 h of exposure, 1332 medical attention and 427 time-loss injuries were observed. Positive relationships were observed between week-to-week change in exposure and overuse time-loss (+1 Z-score hazard ratio (HR), 1.27; 95% confidence interval (CI), 1.06-1.53) and medical attention injury risk (+1 Z-score HR, 1.17; 95% CI, 1.06-1.28). A negative relationship was observed between 7-d accumulated exposure and overuse medical attention injury risk (+1 Z-score HR, 0.74; 95% CI, 0.66-0.84). Overuse time-loss injury risk was greater in soloists compared with the corps de ballet (HR, 1.47; 95% CI, 1.01-2.15) and in dancers with a higher previous injury rate (+1 injury per 1000 h HR, 1.06; 95% CI, 1.02-1.10). Only age was associated with traumatic time-loss (+1-yr HR, 1.05; 95% CI, 1.01-1.09) or medical attention injury risk (+1-yr HR, 1.04; 95% CI, 1.01-1.07).

CONCLUSIONS

Professional ballet companies should implement training principles such as periodization and progression, particularly in the case of senior-ranking dancers, older dancers, and dancers with high rates of previous injury. These findings provide a basis for future prospective investigations into specific causal injury pathways.

Injury, Illness, and Training Load in a Professional Contemporary Dance Company: A Prospective Study

CONTEXT

Professional dance is a demanding physical activity with high injury rates. Currently, no epidemiologic data exist regarding the incidence of injury and illness together with training load (TL) over a long period of time.

OBJECTIVE

To provide a detailed description of injury, illness, and TL occurring in professional contemporary dancers.

DESIGN

Descriptive epidemiology study.

SETTING

A single professional contemporary dance company during a 1-year period.

PATIENTS OR OTHER PARTICIPANTS

A total of 16 male and female professional contemporary dancers.

MAIN OUTCOME MEASURE(S)

Injury data consisted of medical-attention injury (Med-Inj) and time-loss injury (Time-Inj). Illness was measured using the Wisconsin Upper Respiratory Tract Infection Survey. Training load was collected for each dance session using the session rating of perceived exertion and classified into 3 groups based on individual and group percentiles: low, medium, or high.

RESULTS

Reported injuries totaled 79 (86.1% new, 6.3% reinjury, and 7.6% exacerbation). The Med-Inj incidence rate was 4.6 per 1000 hours (95% confidence interval [CI] = 3.8, 5.8), and the Time-Inj rate was 1.4 per 1000 hours (95% CI = 0.8, 2.1). The median time until injury for Med-Inj and Time-Inj was 3 months. The number of days dancers experienced illness symptoms was 39.9 ± 26.9 (range = 1-96), with an incidence rate of 9.1 per 1000 hours (95% CI = 7.7, 10.7). Mean weekly TL was 6685 ± 1605 (4641-10 391; arbitrary units). Inconsistent results were found for the incidence of injury and illness based on individual and group categorizations of TL.

CONCLUSIONS

Professional dancing is associated with high injury and illness rates. This is worrying from a health perspective and underlines the need for further studies to understand how to decrease the risk. The TL is higher than in other sport disciplines, but whether the high incidence of injuries and illnesses is related to high training demands needs additional investigation, possibly conducted as international, multicenter collaborative studies.

The Training-Performance Puzzle: How Can the Past Inform Future Training Directions?

Over the past 20 years, research on the training-load-injury relationship has grown exponentially. With the benefit of more data, our understanding of the training-performance puzzle has improved. What were we thinking 20 years ago, and how has our thinking changed over time? Although early investigators attributed overuse injuries to excessive training loads, it has become clear that rapid spikes in training load, above what an athlete is accustomed, explain (at least in part) a large proportion of injuries. In this respect, it appears that overuse injuries may arise from athletes being underprepared for the load they are about to perform. However, a question of interest to both athletic trainers (ATs) and researchers is why some athletes sustain injury at low training loads, while others can tolerate much greater training loads? A higher chronic training load and well-developed aerobic fitness and lower body strength appear to moderate the training-injury relationship and provide a protective effect against spikes in load. The training-performance puzzle is complex and dynamic-at any given time, multiple inputs to injury and performance exist. The challenge facing researchers is obtaining large enough longitudinal data sets to capture the time-varying nature of physiological and musculoskeletal capacities and training-load data to adequately inform injury-prevention efforts. The training-performance puzzle can be solved, but it will take collaboration between researchers and clinicians as well as an understanding that efficacy (ie, how training load affects performance and injury in an idealized or controlled setting) does not equate to effectiveness (ie, how training load affects performance and injury in the real-world setting, where many variables cannot be controlled).

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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