Injuries across a pre-professional ballet and contemporary dance tertiary training program: A retrospective cohort study.

OBJECTIVES: The study aims to analyse the incidence of medical attention injuries, subsequent injuries, and the median time to injury, across tertiary ballet and contemporary dance training programs. DESIGN: Retrospective cohort. METHODS: Consenting ballet and contemporary dance students completing the third/final year of two tertiary programs were included. The three-year programs consisted of six semesters. Access was granted to onsite physiotherapy notes, timetables, and academic enrolment. Injury was defined as requiring medical attention. Injury and exposure data were extracted, injuries coded for location and tissue, and subsequent injuries, occurring after an initial index injury, categorised. Mean, standard deviation, range, injury incidence, risk and rate ratios, proportions and Kaplan-Meier curves were calculated to report participant characteristics, and injury patterns across three years of the dance program. RESULTS: All 17 students (mean age=20.7 years; standard deviation=1.32) from one program consented to participate, of which all were injured across the three-year program, with 2.71 (95% confidence interval: 2.22, 3.20) injury incidence rate per 1000h, and increasing injury incidences seen across the program. The most injured site and tissue were the ankle (17.65%) and muscle (23.53%) respectively. 74.86% of subsequent injuries were different (affecting a different location and tissue), and 4.88% reinjuries (affecting the same location, tissue, and structure after recovery). The median time to the first injury was seven weeks in the first semester, and later in subsequent year levels. CONCLUSIONS: Increasing injury incidences were seen across the program. Most subsequent injuries were different from previous injuries in this cohort. Future research should use exposure measures beyond hours (i.e. intensity) and consider subsequent injuries.

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.

The impact of environmental temperature deception on perceived exertion during fixed-intensity exercise in the heat in trained-cyclists.

PURPOSE: This study examined the effect of environmental temperature deception on the rating of perceived exertion (RPE) during 30 min of fixed-intensity cycling in the heat. METHODS: Eleven trained male cyclists completed an incremental cycling test and four experimental trials. Trials consisted of 30 min cycling at 50% Pmax, once in 24 °C (CON) and three times in 33 °C. In the hot trials, participants were provided with accurate temperature feedback (HOT), or were deceived to believe the temperature was 28 °C (DECLOW) or 38 °C (DECHIGH). During cycling, RPE was recorded every 5 min. Rectal and skin temperature, heart rate and oxygen uptake were continuously measured. Data were analysed using linear mixed model methods in a Bayesian framework, magnitude-based inferences (Cohens d), and the probability that d exceeded the smallest worthwhile change. RESULTS: RPE was higher in the heat compared to CON, but not statistically different between the hot conditions (mean [95% credible interval]; DECLOW: 13.0 [11.9, 14.1]; HOT: 13.0 [11.9, 14.1]; DECHIGH: 13.1 [12.0, 14.2]). Heart rate was significantly higher in DECHIGH (141 b·min-1 [132, 149]) compared to all other conditions (DECLOW: 138 b·min-1 [129, 146]; HOT: 138 b·min-1 [129, 145]) after 10 min; however, this did not alter RPE. All other physiological variables did not differ between the hot conditions. CONCLUSION: Participants were under the impression they were cycling in different environments; however, this did not influence RPE. These data suggest that for trained cyclists, an awareness of environmental temperature does not contribute to the generation of RPE when exercising at a fixed intensity in the heat.

Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat.

This study examined the effects of post-exercise cooling on recovery of neuromuscular, physiological, and cerebral hemodynamic responses after intermittent-sprint exercise in the heat. Nine participants underwent three post-exercise recovery trials, including a control (CONT), mixed-method cooling (MIX), and cold-water immersion (10 °C; CWI). Voluntary force and activation were assessed simultaneously with cerebral oxygenation (near-infrared spectroscopy) pre- and post-exercise, post-intervention, and 1-h and 24-h post-exercise. Measures of heart rate, core temperature, skin temperature, muscle damage, and inflammation were also collected. Both cooling interventions reduced heart rate, core, and skin temperature post-intervention (P < 0.05). CWI hastened the recovery of voluntary force by 12.7 ± 11.7% (mean ± SD) and 16.3 ± 10.5% 1-h post-exercise compared to MIX and CONT, respectively (P < 0.01). Voluntary force remained elevated by 16.1 ± 20.5% 24-h post-exercise after CWI compared to CONT (P < 0.05). Central activation was increased post-intervention and 1-h post-exercise with CWI compared to CONT (P < 0.05), without differences between conditions 24-h post-exercise (P > 0.05). CWI reduced cerebral oxygenation compared to MIX and CONT post-intervention (P < 0.01). Furthermore, cooling interventions reduced cortisol 1-h post-exercise (P < 0.01), although only CWI blunted creatine kinase 24-h post-exercise compared to CONT (P < 0.05). Accordingly, improvements in neuromuscular recovery after post-exercise cooling appear to be disassociated with cerebral oxygenation, rather reflecting reductions in thermoregulatory demands to sustain force production.