Associations Between Static and Dynamic Field Balance Tests in Assessing Postural Stability of Female Undergraduate Dancers.

Balance testing on dancers has used a wide variety of assessment tools. However, as most field balance tests have been developed for either sport or elderly populations, the evidence of associations between tests and their functional relevance to dance is inconclusive. We assessed possible associations between five such field balance tests . A total of 83 female undergraduate dance students (20 ± 1.5 years; 163 ± 6.6 cm; 61 ± 10.8 kg) volunteered for the tests. They executed the Star Excursion Balance Test (SEBT), the modified Romberg test, the Airplane test, the BioSway Balance System (Biodex, Shirley, New York, USA), and a dance-specific pirouette test. Spearman's correlation coefficients examined relationships between the measures of the balance tests. Results showed strongest relationships between some SEBT reach directions (p < 0.01) and very weak to moderate relationships between some balance tests, including some SEBT directions, Romberg, Airplane, Biosway, and pirouette (p < 0.01 and p < 0.05). Our findings suggest that current tests used to assess dancers' postural stability need further investigation to ensure functionality and relevance.

Bilateral Differences in Dancers' Dynamic Postural Stability During Jump Landings.

Although traditional dance training aims to train dancers' legs equally, the recognized practice of predominately starting and repeating exercises on one side more than the other has led to suggestions that technique classes may cause lateral bias. Such an imbalance could lead to a greater risk of injury; however, despite this potential risk, little is known about the effects of bilateral differences on dancers' postural stability during jump landings, a key dynamic action in dance. Therefore, the aim of this study was to examine the effects of possible bilateral differences on dynamic postural stability during single-leg landing using a time-to-stabilization protocol. Thirty-two injury-free female university undergraduate dancers (19 ± 1.9 years; 164.8 ± 6.7 cm; 62.6 ± 13.6 kg) volunteered for the study. They completed a two-foot to one-foot jump over a bar onto a force platform while stabilizing as quickly as possible. The landing leg was randomly assigned, and participants completed three trials for each leg. No significant differences in dynamic postural stability between right and left legs were revealed, and poor effect size was noted (p > 0.05): MLSI: t = -.04, df = 190, p = 0.940 (CI = -.04, .04, r² = 0); APSI: t = .65, df = 190, p = 0.519 (CI = -.06-, .12, r² = .09); VSI: t = 1.85, df = 190, p = 0.066 (CI = -.02, .68, r² = .27); DPSI: t = 1.88, df = 190, p = 0.061 (CI = -.02, .70, r² = .27). The results of this study do not support the notion that dance training may cause lateral bias with its associated risk of injury. Furthermore, dancers' self-perceptions of leg dominance did not correlate with their ability to balance in single-leg landings or to absorb the ground reaction forces often associated with injury. Even when biased training exists, it may not have detrimental effects on the dancer's postural stability.

Associations Between Balance Ability and Dance Performance Using Field Balance Tests.

AIMS: Although balance is a key element of dance, it remains to be confirmed which balance components are associated with dance performance. The aim of this study was to assess the associations between different field balance tests and dance performance in an in-house measure in ballet, contemporary, and jazz genres. METHODS: 83 female undergraduate dance students (20±1.5 yrs, 163.04±6.59 cm, 60.97±10.76 kg) completed the Star Excursion Balance Test (SEBT), the airplane test, a dance-specific pirouette test, the modified Romberg test, and the BioSway™ Balance System. Results from these balance tests were compared to the participants' technique and repertoire performance scores in ballet, contemporary, and jazz genres. RESULTS: Ballet scores were best predicted by SEBT 90° and Romberg for technique (r=0.4, p=0.001, SEE ±2.49) and Romberg, SEBT 90°, and SEBT 225° for repertoire (r=0.51, p=0.001, SEE±1.99). Contemporary data indicated SEBT 90° and Romberg for technique (r=0.37, p=0.001, SEE±2.67) and SEBT 225° for repertoire (r=0.27, p=0.015, SEE±2.29). Jazz indicated SEBT 90°, Romberg, SEBT 315°, and SEBT 225° for technique (r=0.51, p=0.001, SEE±2.28) and SEBT 225° and Romberg for repertoire (r=0.41, p=0.001, SEE±2.29). CONCLUSION: The present study suggests that balance ability has a limited influence on dance performance, with existing field balance tests demonstrating low to moderate associations with dance technique and repertoire.

Balance in Theatrical Dance Performance: A Systematic Review.

AIM: Due to movement complexity and the use of interdisciplinary styles, all theatrical dance genres require dancers to have excellent balance skills to meet choreographic demands. The aim of this systematic review was to evaluate the experimental evidence for the relationship between balance and dance performance, including balance testing, balance training, and balance performance. The key focus was on balance and theatrical styles of dance, involving adult participants who were either in full-time dance training or professional dancers. METHODS: The databases MEDLINE, PubMed, Cumulative Index to Nursing & Allied Health (CINAHL), SPORTDiscus, Cochrane, ScienceDirect, and Google Scholar were searched using MeSH terms "postural balance," "balance, postural," "musculoskeletal equilibrium," and "postural equilibrium," and used in combination with "dance," between 1980 and 2016. PRISMA recommendations were applied in modifications to the search terms. RESULTS: The initial search revealed 1,140 published articles. After applying inclusion and exclusion criteria, 47 articles were judged to be relevant for further assessment using the GRADE system. Results revealed only 1 randomized controlled trial (RCT); the remaining articles were experimental without randomisation or pre-experimental, thus achieving low scores. A total of 39 articles focused on balance ability, including postural sway and control; 5 were related to multi-joint coordination; and 3 investigated laterality and balance. Female ballet dancers were the most studied population, while a wide range of measurement tools and balance tasks were employed. CONCLUSION: The available material on balance and dance performance is of rather low quality. There is a need for more RCTs and intervention balance studies.

Assessment of Maximum Aerobic Capacity and Anaerobic Threshold of Elite Ballet Dancers.

An athlete's cardiorespiratory profile, maximal aerobic capacity, and anaerobic threshold is affected by training regimen and competition demands. The present study aimed to ascertain whether there are company rank differences in maximal aerobic capacity and anaerobic threshold in elite classical ballet dancers. Seventy-four volunteers (M 34, F 40) were recruited from two full-time professional classical ballet companies. All participants completed a continuous incremental treadmill protocol with a 1-km/hr speed increase at the end of each 1-min stage until termination criteria had been achieved (e.g., voluntary cessation, respiratory exchange ratio <1.15, HR ±5 bpm of estimated HRmax). Peak VO2 (5-breathe smooth) was recorded and anaerobic threshold calculated using ventilatory curve and ventilatory equivalents methods. Statistical analysis reported between-subject effects for gender (F1,67=35.18, p<0.001) and rank (F1,67=8.67, p<0.001); post hoc tests reported soloists (39.5±5.15 mL/kg/min) as having significantly lower VO2 peak than artists (45.9±5.75 mL/kg/min, p<0.001) and principal dancers (48.07±3.24 mL/kg/min, p<0.001). Significant differences in anaerobic threshold were reported for age (F1,67=7.68, p=0.008) and rank (F1,67=3.56, p=0.034); post hoc tests reported artists (75.8±5.45%) having significantly lower anaerobic threshold than soloists (80.9±5.71, p<0.01) and principals (84.1±4.84%, p<0.001). The observed differences in VO2 peak and anaerobic threshold between the ranks in ballet companies are probably due to the different rehearsal and performance demands.

Effect of midsole thickness of dance shoes on dynamic postural stability.

Landing from jumps is one of the main causes of injury within dance. A number of studies have reported a negative effect of shoe midsole thickness on lower limb kinematics during running due to the reduction in afferent sensory outputs from the foot's epithelium. The purpose of this study was to examine the influence of varying midsole thicknesses in dance shoes on dynamic postural stability during a single-leg landing. Twenty-eight female undergraduate dance participants volunteered for the study. They carried out three trials under four conditions: barefoot and in ballet flats (2 mm midsole thickness), jazz shoes (7 mm), and dance sneakers (30 mm). The task consisted of a single-leg forward jump over a hurdle at 50% of their maximal vertical jump height, landing on a force platform, and balancing for 3 seconds. The stability indices for vertical stability (VSI), anterior-posterior stability (APSI), medial-lateral stability (MLSI), and dynamic postural stability (DPSI) were calculated using Wikstrom's revised method. Significant differences were reported between the midsole thicknesses for both DPSI and VSI (p<0.01). No statistical differences were noted for the indices SPSI or MLSI. The present data agree with the running studies in that increased midsole thickness has a negative influence on landing stability.