Abstracts from the current literature.
This investigation sought to determine the energy intake and energy expenditure of pre-professional female contemporary dancers. Twenty-five female contemporary dance students completed the study Over a 7-day period, including five week days (with scheduled dance training at a conservatoire) and two weekend days (with no scheduled dance training), energy intake (self-reported weighed food diary and 24 h dietary recall) and expenditure (tri-axial accelerometry) were recorded. Mean daily energy intake and expenditure were different over the 7-day period (p = 0.014), equating to an energy deficit of-356 [+ or -] 668 kcal [less than or equal to] [day.sup.-1] (or -1.5 [+ or -] 2.8 MJ [less than or equal to] [day.sup.-1]). Energy expenditure was not different when comparing week and weekend days (p = 0.297). However, daily energy intake (p = 0.002), energy availability (p = 0.003), and energy balance (p = 0.004) were lower during the week compared to the weekend, where energy balance became positive. The percentage contribution of macronutrients to total energy intake also differed, with higher fat (p = 0.022) and alcohol (p = 0.020), and lower carbohydrate (p = 0.001) and a trend for lower protein (p = 0.051) at the weekend. Energy balance and appropriate macronutrient intake are essential for maintaining the demands of training, performance, and recovery. While aesthetics are important, female contemporary dancers may be at risk for the numerous health and performance impairments associated with negative energy balance, particularly during periods of scheduled training.
Zaferiou AM, Flashner H, Wilcox RR, McNitt-Gray JL. Lower extremity control during turns initiated with and without hip external rotation. J Biomech. 2017 Feb 8;52:130-9.
The purpose of this study was to compare lower extremity control strategies during the turn initiation phase of pirouettes performed with and without hip external rotation. Skilled dancers (N = 5) performed pirouette turns with and without hip external rotation. Joint kinetics during turn initiation were determined for both legs using ground reaction forces (GRFs) and segment kinematics. Hip muscle activations were monitored using electromyography. Using probability-based statistical methods, variables were compared across turn conditions as a group and within-dancer. Despite differences in GRFs and impulse generation between turn conditions, at least 90% of each GRF was aligned with the respective leg plane. A majority of the net joint moments at the ankle, knee, and hip acted about an axis perpendicular to the leg plane. However, differences in shank alignment relative to the leg plane affected the distribution of the knee net joint moment when represented with respect to the shank versus the thigh. During the initiation of both turns, most participants used ankle plantar flexor moments, knee extensor moments, flexor and abductor moments at the push leg's hip, and extensor and abductor moments at the turn leg's hip. Representation of joint kinetics using multiple reference systems assisted in understanding control priorities.
Watanabe K, Michikawa T, Yonezawa I, Takaso M, Minami S, Soshi S, Tsuji T, Okada E, Abe K, Takahashi M, Asakura K, Nishiwaki Y, Matsumoto M. Physical activities and lifestyle factors related to adolescent idiopathic scoliosis. J Bone Joint Surg Am. 2017 Feb 15;99(4):284-94.
This cross-sectional study was conducted to explore lifestyle factors related to adolescent idiopathic scoliosis (AIS). It included 2,600 Japanese female junior high school students who planned a secondary screening after an initial moire topography screening indicated possible scoliosis. The students and their mothers, or guardians, were asked to fill out a questionnaire consisting of 38 questions about demographic factors, lifestyle-related factors, social factors, household environment, participation in sports, health status, and factors related to the mother's pregnancy and delivery. After undergoing a secondary screening with standing radiographs of the spine, students were assigned to the normal (control) group if radiographs showed a curve of < 15[degrees] or to the scoliosis group if they had a curve of [greater than or equal to] 15[degrees]. The odds ratios (ORs) for AIS in relation to possible risk or preventive factors were estimated by logistic regression analyses. No lifestyle-related factor was significantly associated with AIS. However, AIS was associated with classical ballet training (OR, 1.38; 95% confidence interval [CI], 1.09 to 1.75); the odds of AIS developing increased as the child's frequency of training, number of years of experience, and duration of training in ballet increased. The OR for AIS was 1.5 times higher for participants whose mothers had scoliosis. AIS was also associated with a low body mass index (BMI). These associations remained even after mutual adjustment was performed. No association was found between AIS and lifestyle-related factors. However, classical ballet training, a family history of scoliosis, and low BMI may be associated with AIS.
Zaletel P, Sekulic D, Zenic N, Esco MR, Sajber D, Kondric M. The association between body-built [sic] and injury occurrence in pre-professional ballet dancers - Separated analysis for the injured body-locations. Int J Occup Med Environ Health. 2017 Feb 21;30(1):151-9.
This study has aimed at identifying prevalence of injury occurrence in 24 pre-professional ballet dancers (females, 16-18 years of age), and identifying the associations between the body-built [sic] and prevalence of injuries. The sample of variables included: body mass, body height, and three somatotype characteristics (mesomorph, ectomorph, and endomorph) and data on injuries over the preceding year. Dancers were mostly ectomorphic-mesomorph (endomorphy: 2.6 [+ or -] 0.54, mesomorphy: 3.99 [+ or -] 0.77, ectomorphy: 3.23 [+ or -] 0.54). The most commonly injured locations were the foot (17% of all injuries) and ankle (17%). The majority of the injuries occurred while practicing, but 37% of hip injuries occurred while performing. Ankle injuries resulted in the longest absence from ballet. Endomorphy was related to ankle injury (odds ratio [OR] = 1.9, 95% confidence interval [CI]: 1.4-2.3), ectomorphy to foot injury (OR = 1.7, 95% CI: 1.1-2.9), and body mass to injury to the toes (OR= 1.7, 95% CI: 1.4-3.1). The results of this study allow for recognizing those dancers who are particularly vulnerable to injuries of certain body parts. A more profound analysis of the possible mechanisms that lead to hip injury during performance is needed.
Jacobs CL, Cassidy JD, Cote P, Boyle E, Ramel E, Ammendolia C, Hartvigsen J, Schwartz I. Musculoskeletal injury in professional dancers: prevalence and associated factors: an international cross-sectional study. Clin J Sport Med. 2017 Mar;27(2):153-60.
The purpose of the study was to determine the prevalence and factors associated with injury in professional ballet and modern dancers and assess if dancers are reporting their injuries and explore reasons for not reporting injuries. Participants were recruited from nine professional ballet and modern dance companies in Canada, Denmark, Israel, and Sweden. Sociodemographic variables included age, sex, height, weight, and before-tax yearly or monthly income. Dance specific characteristics included number of years in present dance company, number of years dancing professionally, number of years dancing total, and rank in the company. The main outcome measures were self-reported injury and self-estimated functional inability because of pain. A total of 260 dancers participated in the study. The point prevalence of self-reported injury in professional ballet and modern dancers was 54.8% (95% CI, 47.7-62.1) and 46.3% (95% CI, 35.5-57.1), respectively. Number of years dancing professionally (OR= 4.4, 95% CI, 1.6-12.3) and rank (OR = 2.4, 95% CI, 1.2-4.8) were associated with injury in ballet dancers. More than 15% of all injured dancers had not reported their injury and their reasons for not reporting injury varied. It is concluded that the prevalence of injury is high in professional dancers, with a significant percentage not reporting their injuries. Number of years dancing and rank are associated with injury in professional ballet dancers.
Cahalan R, Purtill H, O'Sullivan K. Biopsychosocial factors associated with foot and ankle pain and injury in Irish dance: a prospective study. Med Probl Perform Art. 2017 Jun;32(2):111-7.
Foot and ankle pain and injury (FAPI) are the most common musculoskeletal problems suffered in Irish dancing. A prospective examination of risk factors for FAPI in this cohort has never been performed. Eighty-five elite adult Irish dancers were screened at baseline for biopsychosocial factors and followed up prospectively each month for 1 year to evaluate FAPI rates and potential risk factors. Subjects who suffered from multiple incidences of FAPI or at least one moderate episode of FAPI were allocated to the foot-ankle-injured (FAI) group (N = 28, 25 F, 3 M). Subjects reporting no pain/injury or only one minor FAPI were allocated to the non-injured group (N = 21, 14 F, 7 M). Baseline differences in variables between groups were tested with the independent samples t-test, Mann-Whitney U-test for skewed data, and Fisher's exact test for categorical variables. Baseline factors significantly associated with the FAI group included failing to always perform a warm-up (p = 0.042), lower levels of energy (p = 0.013), and more bothersome pain (p = 0.021). Subjects also scored worse on two dimensions of the Athletic Coping Skills Inventory: i.e., coping with adversity (p = 0.035) and goal setting and mental preparation (p = 0.009). It is concluded that several biopsychosocial factors appear to be associated with FAPI in Irish dancers. Biopsychosocial screening protocols and prevention strategies may best identify and support at-risk dancers.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||energy intake and expenditures in contemporary dancing / lower extremity control / adolescent idiopathic scoliosis|
|Author:||Solomon, Ruth; Solomon, John|
|Publication:||Journal of Dance Medicine & Science|
|Date:||Jul 1, 2017|
|Previous Article:||The biomechanics and motor control of tap dancing.|
|Next Article:||Dance Psychology for Artistic and Performance Excellence.|