Moving together - benefits of an online dance program on physical and mental health for older women: an exploratory mixed-method study.

BACKGROUND: Previous studies show that in-person dance training is a beneficial form of physical activity that involves mental, social, and physical dimensions. This exploratory study investigated the benefits of a 12-week online dance training intervention on mental and physical health outcomes for older women. METHODS: A convergent parallel mixed-method design was used. Forty-five older adults (74.0 ± 5.3 yrs old, 44 women) were recruited through advertisements at activity and rehabilitation centers in the North Denmark region. The intervention consisted of two weekly 60-min classes of improvisation and salsa delivered online through video call applications. Changes in physical health outcomes (body mass and composition, resting blood pressure, Senior Fitness Test battery) and self-rated health and wellbeing (health-related quality of life (HRQOL), feelings of loneliness) were assessed prior to and after 12 weeks of dancing. Focus group interviews were conducted post-intervention to further explore the benefits as well as the participant's experience of the intervention. Thematic analysis of the qualitative data was conducted. RESULTS: Thirty-two participants (all women) completed the study. Significant improvements in fitness were found for the number of arm curls performed (baseline: 12.3 ± 3.0; post-intervention: 13.7 ± 3.0, P = 0.005), 2-min step test performance (baseline: 66.5 ± 20.0 reps.; post-intervention: 73.8 ± 22.6 reps., P = 0.016), and chair sit-and-reach (baseline: 0.4 ± 11.3 cm; post-intervention: 5.5 ± 10.1 cm, P < 0.001). There was a significant increase in body mass from baseline to post-intervention (P < 0.015). The themes from the focus groups included (1) Participation, (2) Challenges, (3) Progression, (4) Motivation, (5) Perceived health and wellbeing, and (6) Online dance instruction. No significant changes were reported in HRQOL and loneliness from the quantitative data, although the qualitative data did reveal improved feelings of physical health and wellbeing. CONCLUSIONS: The intervention improved several aspects of fitness in older women and improved the participants' perceptions of their own physical abilities and wellbeing. While most participants found the online intervention enjoyable, several participants missed the feedback from the instructors that naturally occurs with in-person instruction.

Prevalence and risk factors of musculoskeletal injuries in modern and contemporary dancers: a systematic review and meta-analysis.

Background: A large number of studies have found that the musculoskeletal injury of modern and contemporary dancers has a high incidence. Previous publications have indicated that there are many potential factors that are related to dancing injury; however, they have not been proven, and even some data are conflicting in different research. Results: The search yielded 18 prospective studies reporting on professional and pre-professional modern or contemporary dancers from companies and schools. The prevalence of modern and contemporary dancers was 0.82 (95% CI: 0.74~0.90). The injury proportion of trauma, overuse, ankle and foot, lower extremity, joint and ligaments, muscle and tendons, and time-loss were 0.40, 0.26, 0.49, 0.34, 0.33, and 0.29 in the total number of injuries. There was no evidence of a significant difference in sex, age, and education program. The factors of BMI and injury history achieved statistical significance, and the p-values were less than 0.01. Conclusion: Based on the results of this article, BMI and injury history may be risk factors for injury in contemporary and modern dancers. Modern and contemporary dancers have a high prevalence of musculoskeletal injuries. Lower extremity injuries are the most common in the whole body, with injuries to the foot and ankle being more frequent. The mechanism of injury is mostly overuse injury, and the injured tissues are mostly muscle tendons and joint ligaments.

Effects of Five Common Preparatory Approaches on Grand Jeté Biomechanics.

Introduction: The grand jeté requires grace and proper biomechanics to produce the iconic glide through the air. Understanding how the preceding choreographed movements affect take-off and flight may influence teaching and training. We sought to examine the effects of 5 common preparatory approaches on grand jeté biomechanics. Methods: One male and 19 female dancers (19.3 ± 1.4 years; 1.61 ± 0.05 m; 58.1 ± 7.3 kg) with 12.5 ± 4.8 years of formal ballet experience performed grand jetés from run, chaine, chasse, assemble, and step-step approaches. Plié angle (deg), vGRF (BW), leap height (m), and leap distance (m) were measured with a motion analysis system and a force plate. One-way repeated measures ANOVAs were conducted to compare variables between approaches and Bonferroni tests were used for pairwise comparisons. Results: Plié depth, vGRF, leap height, and leap distance were all significantly different (P < .001). Plié angles (43.6-68.2 deg) were deepest for the assemble and shallowest for the run. vGRF (2.46-3.81 BW) were greatest for the assemble versus all but the run, and smallest for the chaine. Leap height (0.33-0.41 m) was highest for the run versus the chaine and step-step, but not versus assemble. Height was lowest for the chaine. Leap distance (0.24-1.03 m) was longest for the run and shortest for the assemble. Conclusions: The run approach optimizes the float through the air illusion (high leap height and distance) through applying high vGRF but moderate plié angles. The chasse approach is the next most optimal. The 2-legged assemble requires deeper plié angles to achieve height but produces shorter horizontal distances. Single leg plié training may enhance grand jeté performance and reduce injury risk from approaches such as the run, chaine, chasse, and step-step.Level of Evidence: Level 2.

Dancers Show More Accurate Trunk-Pelvic Joint Angle Reproduction While Wearing a Jacket Augmented With Elastic Bands.

Purpose: The Backalast® compression jacket is intended to improve posture and proprioception of the trunk and shoulder girdle for dancers and dance students during dance training by way of elastic bands in the rear of the garment (which include bands enclosing the inferior thorax). This study was intended to investigate whether there is evidence to support those objectives. Materials and Methods: Fifteen dance students participated (4 male, mean age 19.9 ± 1.4 years old). The dependent variables of trunk-pelvis angle and proximity of trunk axis to global vertical for each participant were measured using optical motion capture before and after the completion of a series of trunk movements. The Helen Hayes model, which we used to represent the trunk, includes the shoulder girdles as part of the trunk. We compared the effect of the type of garment (Backalast® or control compression shirt) worn upon the 2 dependent variables, within-subject with paired t-tests. The order of whether Backalast® or control compression shirt was worn first was alternated between participants. Results: The pre/posttest difference in trunk proprioception as represented by the construct of ability to reproduce trunk-pelvis angle wearing the Backalast® was 0.8° ± 0.8°, but for the control shirt, the difference was 1.8° ± 1.4°, P = .03. The difference between garments in vertical trunk alignment, measured after the series of trunk movements, was not significant. Conclusion: Our findings suggest that the Backalast® can help enhance trunk proprioception when compared to the control compression shirt, although it did not change the angle at which the participants' held their trunks while standing erect (proximity to global vertical).

Differences in Achilles tendon mechanical properties between professional ballet dancers and collegiate athletes utilizing shear wave elastography.

PURPOSE: To report normative stiffness parameters obtained using shear wave elastography in dorsiflexion from the Achilles tendons in asymptomatic professional ballet dancers and compare them with college-level athletes. METHODS: An Institutional Review Board (IRB)-approved study consists of 28 professional ballet dancers and 64 asymptomatic collegiate athletes. The athletes were further subdivided into runner and non-runner disciplines. Shear wave elastography (SWE) measurements were made in maximum ankle dorsiflexion position. RESULTS AND DISCUSSION: Forty-eight (52%) males and 44 (48%) females were examined with an overall mean age of 22.2 (± 3.8 years). There were no significant SWE differences between dominant and non-dominant legs in both groups and comparing spin vs. non-spin leg of ballet dancers (p > 0.05). Ballet dancers had significantly higher short-axis velocity values than runners and non-runners (2.34 m/s increase and 2.79 m/s increase, respectively, p < 0.001). Long-axis velocity was significantly higher in ballet dancers compared to non-runners (by 0.80 m/s, p < 0.001), but was not different between ballet dancers and runners (p > 0.05). Short-axis modulus was significantly higher in dancers compared to runners and non-runners (by 135.2 kPa and 159.2 kPa, respectively, p < 0.001). Long-axis modulus (LAM) was not significantly different in ballet dancers when compared to runners. CONCLUSION: Asymptomatic professional ballet dancers exhibit greater short-axis tendon stiffness compared to athletes and greater long-axis tendon stiffness compared to non-runners but similar to runners. The functional benefit from elevated short-axis stiffness in dancers is not clear but may be related to greater axial loading and adaptations of the tendon matrix.

Low Body Fat Percentage and Menstrual Cycle Disorders in Female Elite Adolescent Dancers.

Introduction: The menstrual cycle is an important indicator of health in female athletes. Female elite adolescent dancers are expected to control their weight while also training intensely, which can lead to menstrual disorders. This study aimed to investigate the relationship between body composition and menstrual status in female elite adolescent dancers. Methods: In total, 131 female elite adolescent dancers (age: 15.9 ± 1.5 years) were enrolled in this study. We measured the height, weight, and body fat percentage (BFP) for each participant and calculated their body mass index (BMI). We gathered information on individual menstruation patterns and the participants' menstrual cycles over the previous year using recall methods. We then compared the differences between dancers with menstrual cycle disorders and those without. Primary amenorrhea was defined as menarche occurring after the age of 15, while secondary amenorrhe was defined as experiencing fewer than 5 or no menstrual periods for at least 3 of the previous 12 months. We conducted a reliability test using the same questionnaire 2 weeks later. Statistical significance was defined as P < .05, and we calculated the effect sizes (d) and 95% confidence intervals (95% CI). Results: The average BMI and BFP were 22.6 ± 3.0% and 19.4 ± 2.2 kg/m2, respectively. Low BFP and low BMI were observed in 51 (38.6%) and 47 (35.6%) participants, respectively. Primary amenorrhea in 3 participants (2.3%) and 29 (22.1%) reported experiencing secondary amenorrhea; they had lower BFP than the dancers who did not experience amenorrhea (P = .041, 95% CI, -2.51 to -0.05). Conclusion: Female elite adolescent dancers in China may have lower BFP and menstrual problems. Given that lower BFP may contribute to the occurrence of menstruation disorders, it is essential to pay an attention to both BFP and the menstruation status in female elite adolescent dancers.

The Effects of Pointe Shoes on Ballet Dancers' Biomechanics, Muscle Activity, Movement and Symptoms: A Scoping Review.

Introduction: Dancing en pointe requires ballet dancers to stand on the tips of their toes while wearing a structured pointe shoe. Understanding the effect of pointe shoes on ballet dancers' biomechanics, function, symptoms and skin health is essential to guide shoe development and ultimately improve dancer performance. Therefore, the purpose of this scoping review was to map the evidence and identify knowledge gaps related to the effect of wearing pointe shoes on professional and recreational ballet dancers. Method: A scoping review was conducted by searching 6 electronic databases and the International Association for Dance Medicine and Science Bibliography. Results: Thirty-five studies were grouped into 5 categories: pointe shoe factors (eg, toe box and shank, pointe shoe status; 9 studies), shoe types (eg, flat shoes vs demi pointe vs pointe; 10 studies), ballet movements (11 studies), symptoms (5 studies), and intrinsic dancer factors (eg, foot type/toe length; 7 studies). Studies were published between 1979 and 2023, with 72% (n = 23) published between 2006 and 2020. Most (86%) of the studies were cross-sectional. Most studies explored biomechanical outcomes and the most common data collection device was force plates (19 studies). Overall, there was an insufficient volume of evidence for specific research aims. Significant gaps in knowledge exist regarding functional and performance-based outcomes, injury outcomes including exploration of factors such as shoe age/usage, and pointe shoe treatment factors. Conclusions: Currently the field of research suffers from threats to ecological validity, with many study methods not reflecting ballet-specific demands or environments. The impact of pointe shoes on ballet dancers is a developing research area, and this scoping review can help guide future research decisions. Studies need to target the knowledge gaps and employ rigorous ecologically valid study designs and ensure that findings inform shoe design and dancer education to minimize injury and maximize comfort and performance.

Plantar intrinsic foot muscle activity and its relationship with postural sway during tiptoe standing in ballet dancers and non-dancers.

BACKGROUND: Minimizing postural sway during tiptoe standing is essential for ballet dancers. Investigation of the activity of the plantar intrinsic foot muscles (PIFMs) may provide insight into postural sway in dancers. Herein, we compared PIFM activity during tiptoe standing between dancers and non-dancers and examined its relationship with postural sway. METHODS: We enrolled 14 female ballet dancers and 13 female non-dancers. Electromyography (EMG) amplitudes of 64 channels of PIFMs and center of pressure (COP) data were recorded during bipedal tiptoe standing tasks performed with ankle plantarflexion angles of 20°, 40°, and 60° (dancers only). The EMG amplitudes were normalized to those during the maximum voluntary contraction, and the muscle activity level and its coefficient of variation over time (EMG-CVtime) during the task were assessed. Standard deviations in the anteroposterior and mediolateral directions, velocity, and area were calculated from the COP data. RESULTS: Most COP and EMG variables were significantly lower in dancers than in non-dancers in both the 20° and 40° tasks (p < 0.05). Significant correlations were found between most combinations of the COP and EMG variables in both the 20° and 40° tasks in the whole cohort (r = 0.468-0.807, p ≤ 0.014). In the 60° task in dancers, COP velocity was strongly correlated with EMG-CVtime (r = 0.700, p = 0.005). CONCLUSION: These results provide novel evidence that the PIFMs do not require high activity, but rather that its low, steady activity is the key, to achieve less postural sway during bipedal tiptoe standing in dancers.

Balletic bodies under lockdown: The consequences of a pandemic for highly disciplined habitus.

Like other elite athletes, ballet dancers are highly dedicated to the pursuit of their vocation. They work to perfect their bodies, their movements and their expression of the art form. The lockdowns that occurred during the COVID-19 pandemic represented a significant interruption to the extraordinary but everyday lives of ballet dancers, creating unique environments where exploration of the embodied habitus of ballet can be further investigated. The impacts of lockdown upon dancers were explored via a series of interviews with 12 professional dancers from Germany. Framed by previous research, theorising the balletic body from a Bourdieusian perspective, interview data were analysed using Interpretative Phenomenological Analysis. Our research highlights the way in which COVID-19 lockdowns and associated restrictions disrupt the habitus of dancers and results in a form of suffering that is comparable to injury or chronic illness. Our research suggests that individuals respond to the 'structural injuries' of lockdown measures in a manner comparable to the way they respond to physiological injury. Thus, dancers sought to repair or re-establish the social structures they ordinarily inhabit whilst the inevitable limitations of such efforts engendered occasions for reflexive thinking about their role, careers and identity as dancers.

Jumping demands during classical ballet class.

Ballet class represents a considerable portion of professional ballet training, yet the external training load demands associated with class-and particularly the jumping demands-have not been investigated. The purpose of this study was to measure the jumping demands of ballet class by sex and rank. Eleven female and eight male elite professional ballet dancers participated in 109 ballet classes taught by 12 different teachers. Jump counts and jump heights were measured during each class. A Poisson generalized linear mixed effects model was used to examine the differences in jump counts between sexes and ranks. Greater jump counts were observed during class in men than in women (153, 95% confidence intervals [CI] [137, 170] vs. 119, 95% CI [109, 131], p = 0.004) and in junior ranking dancers compared with senior ranking dancers (151, 95% CI [138, 165] vs. 121, 95% CI [108, 135], p = 0.006). Female junior and senior ranking dancers jumped at rates of 9.2 ± 2.6 and 8.6 ± 4.7 jumps·min-1 , respectively, while male junior and senior ranking dancers jumped at rates of 9.1 ± 2.6 and 8.7 ± 2.6 jumps·min-1 , respectively. Across all classes, 73% of jumps observed were below 50% of maximum double-legged countermovement jump height. Unlike rehearsals and performances, class offers dancers an opportunity to self-regulate load, and as such, are a useful session to manage jump load, and facilitate gradual return-to-dance pathways. Communication between health care and artistic staff is essential to facilitate load management during class.

Dynamic Gait Stability and Spatiotemporal Gait Parameters During Overground Walking in Professional Ballet Dancers.

Introduction: It has been recognized that practicing ballet could strengthen the leg muscles, improve balance, and reduce fall risk. However, few studies have investigated how ballet practice alters a person's gait pattern, and this knowledge gap could present a barrier to designing ballet-based training programs. This study examined dynamic gait stability and spatiotemporal gait parameters among professional ballet dancers during normal level overground walking. Methods: Twenty young adults were recruited: 10 ballet dancers (24.5 ± 4.9 years) and 10 age- and sex-matched non-dancers (22.6 ± 3.4 years). Participants walked on a 10 m linear walkway at their self-selected speed. Dynamic gait stability and common gait parameters (step length, step width, gait speed, and cadence) were determined from the collected kinematic data and compared between groups with a significance level of .05. Results: The results showed that both groups displayed comparable dynamic gait stability at touchdown (P = .140) and liftoff (P = .638). However, ballet dancers walked with a longer (P = .054), narrower (P = .009), and faster step (P = .014) at a marginally quicker speed (P = .063) than non-dancers. Conclusion: Our study suggests that young professional ballet dancers have different gait patterns, but similar dynamic gait stability compared to non-dancers. These findings not only provide insight into the mechanisms of dynamic stability control among young ballet dancers during gait but expand our understanding of the control of dynamic gait balance of human locomotion across a wide variety of populations and walking conditions.

Strength Training Perceptions Amongst Vocational Circus and Dance Students.

Introduction: The aim of this study was to analyze perceptions of strength training in vocational circus and dance students. It was hypothesized that due to the higher relative strength demands and associated risks of working at height in some aerial and acrobatic disciplines that circus students would be more open to strength training than dancers. Methods: Eighty students completed the Training Information Survey (TIS) (Mean age = 20.74 ± 2.71); 39 circus students and 41 dance students. 97% of circus students and 69% of dance participants reported that strength training was a required part of their training with students participating in strength training 4.24 ± 0.98 and 3.05 ± 1.42 day per week respectively. Results: Perceptions of strength training amongst vocational circus and dance students appear to be favorable, with both sets of students strongly agreeing with the statements "Strength training is essential to my overall development as a dancer/circus artist" (5.00 (IQR 1.00) and 5.00 (IQR 1.00) respectively). Following Bonferonni correction only one statement returned statistically significant results with dance students agreeing more strongly with the statement "Strength training increases muscle size," U = 473.00, P = .001. Students also agreed that strength training helped them to feel better mentally and physically, that strength training is beneficial for both men and women and that it should not be designated as specific to either sex. Conclusion: Results support earlier studies that suggest a cultural shift in perceptions of strength training and ideal esthetic in dance, particularly amongst students and that they are keen to incorporate strength training into their practice. Educational establishments should note students' interest in participating in strength training, reviewing how to embed effective strength training education, more coaching and time allowance for these activities within their timetable. Further research with a greater sample size is recommended to further substantiate these indications of a shift in perceptions.

Kinematic Motor Synergy Analysis to Understand Lock Dance Choreographies.

Lock dance, or locking, is one of the popular old-school street dance styles featuring sharp, sudden, and isolated body movements through intricate control and coordination of joints and muscles. This work aims to understand the complex lock dance motions based on kinematic motor synergy analysis. Lock dance motions performed by three experienced dancers were measured with a markerless human motion capture technique. The motor synergies were identified and summarized using principle component analysis (PCA). The motion complexity, joint contributions, and motor coordination of ten basic lock dance choreographies were analyzed based on the synergy patterns and their activations. The results enhance our understanding of complex dance motions and serve as a step toward future applications to, e.g. dance skill or injury risk assessments.

Different Types of Training Lead to Different Levels of Cardiovascular Energy Dissipation: Young Soccer Players Versus Ballet Dancers.

INTRODUCTION: Arterial wall viscosity is a source of energy dissipation that takes place during mechanical transduction. In our previous studies, a "global" damping effect in endurance training athletes was introduced, verifying that endurance-athletes dissipate greater pulsatile energy in the circulation compared with healthy untrained subjects. OBJECTIVE: To investigate the wall energy dissipation in the vascular bed for each beat and within the conceptual framework of ventricular-arterial coupling, in order to elucidate if different types of training could lead to differentiated levels of cardiovascular energy dissipation. MATERIALS AND METHODS: Data from subjects with different kinds of training (soccer players and ballet dancers) have been collected noninvasively and compared with a control group of untrained individuals to analyse the differentiating characteristics of the subjects, especially in terms of Stroke Work Dissipation (WDIS). RESULTS: In the endurance-trained individuals, an enhanced WDIS has been observed compared to the untrained individuals (p<0.05). However, non-significant differences were found regarding ballet-dancers group. CONCLUSION: Changes in wall energy dissipation are developed under high intensity endurance training routines.

Dermatologic conditions in dancers: a statewide survey.

Performing artists, such as dancers, singers, actors and musicians, rely on their physical bodies to successfully execute their artforms. However, literature regarding dermatologic conditions that impact dancers is lacking. An anonymous REDCap® secure survey was distributed by email to Dance Majors, Dance Minors, and Dance Instructors/Professors at five Virginia undergraduate institutions. Responses regarding demographics, style of dance, and dermatological diseases were recorded over a 2 month period. When asked about developing skin disease, 57 (59%) of survey participants reported experiencing skin diseases, such as acne, eczema, hyperhidrosis, and plantar warts. When asked about skin diseases exacerbated or believed to be caused from dancing, 56 (59%) reported blisters, callouses, skin splitting, nail/foot infection, ingrown nails, and floor burns. This study demonstrates two main findings: dancing may exacerbate current skin disorders and some skin conditions may be caused by dancing. Additionally, the common practice of dancing barefoot likely contributes to the development of certain skin conditions. Limitations include sample size, response bias, and lack of validation of the survey.

Weighting of visual and auditory inputs in dancers with and without previous ankle injury.

Elite dance requires highly controlled balance performance in dynamic visual and auditory environments characterized by the use of stage lighting and music. Perturbing visual input is known to influence balance in dancers, but the effects of sounds have not been clearly established. Ankle inversion injuries are common in dancers and may also play a role in dancers' ability to respond to sensory perturbations. The aims of this study were to identify changes in static balance in response to visual or auditory perturbation in elite collegiate dancers with and without a history of ankle injury, and to describe coupling of measurements obtained from the waist and head during balance. Thirty-seven dancers: 22 controls and 15 with a history of ankle sprain, performed single-leg balance under static and dynamic visual and auditory conditions. Dancers demonstrated increased waist sway when viewing a dynamic visual scene and when presented with moving sounds and increased head sway with dynamic visuals. These results did not vary by history of ankle sprain. While dancers appear to dampen the impact of waist sway on head motion during single leg stance, even highly trained dancers may experience challenges controlling balance under perturbing visual and auditory conditions like those present during stage performance.

The interactions between agonist-to-antagonist muscle strength performance and plantar pressure distribution, foot contact area, and impulse in novice ballet dancers.

BACKGROUND: Hip, trunk, knee, and ankle/foot muscles may lead to increased variability in the components of balance and plantar pressure distribution (PPD) analysis. However, the role of these muscle groups in the PPD of different ballet techniques in novice ballet dancers has not previously been studied. OBJECTIVE: Our objective was to examine whether balance and PPD vary among five different ballet techniques and correlate with the agonist-to-antagonist strength performance of trunk, knee, hip, and ankle muscles in adolescent ballet dancers. METHODS: The anthropometric parameters, muscle strength performance, balance, and PPD of sixty healthy female ballet dancers (age: 14.36 ± 2.18 y) were measured at 48-h intervals. RESULTS: The forefoot's PPD was significantly greater than the midfoot and rearfoot for all techniques (p= 0.000). The percent plantar load of forefoot during développé à la seconde (side, front, back), passé, and penché was greater than midfoot (166.56%, 161.51%, 168.11%, 165.14%, 174.04%) and rearfoot (47.75%, 32.84%, 43.83%, 48.73%, 49.66) for all techniques, respectively. The forefoot's PPD, impulse, and contact area during all techniques were significantly correlated with the trunk muscle strength ratio (p< 0.05). CONCLUSION: Ballet dancers with higher trunk muscle strength imbalance showed a greater percentage difference in pressure load between the left and right foot in the anterior and posterior directions, poor balance, aggravated trunk imbalance, increased PPD, contact area, and impulse in the forefoot during each technique.

Low Stiffness Dance Flooring Increases Peak Ankle Plantar Flexor Muscle Activation During a Ballet Jump.

INTRODUCTION: Research in court sports shows that factors which aid in extrinsic shock absorption, that is, flooring and footwear, can help reduce lower extremity injuries. However, since students and performers of ballet or most styles of contemporary dance cannot depend upon footwear, the only extrinsic factor to help them with shock absorption is flooring. METHODS: We investigated whether doing sauté on a low stiffness dance floor produced a difference in EMG output of the vastus lateralis, gastrocnemius, of soleus compared to a high stiffness floor. Average and average peak amplitude EMG output from 18 dance students or active dancers performing 8 repetitions of sauté on a low stiffness floor (Harlequin® Woodspring) was compared to a maple hardwood floor on concreted subflooring. RESULTS: The data showed a significant increase in average peak EMG muscle amplitude during jumping on the low stiffness floor compared to a high stiffness floor for the soleus muscle (P = .033) and a trend for increase average peak output for the medial gastrocnemius (P = .088). CONCLUSION: The difference in average peak amplitude of EMG output is explained through the difference in force absorption between floors. With the high stiffness floor, more force of the landing was returned to the dancers' legs, but the low stiffness floor absorbed some of the force of landing the jump, and therefore muscles needed to contribute more to maintain the same jump height. The force absorption characteristic of the low stiffness floor may decrease injury rates in dance through causing an adjustment in muscle velocity. Rapid eccentric muscle activity carries the greatest possibility of musculotendinous injury and is experienced in lower body muscles controlling all joints during impact absorption, which includes landing of jumps in dance. If a surface can decelerate the landing of a high velocity dance movement, it also decreases the musculotendinous demand for high velocity tension generation.

Differences in Center of Pressure Displacement and Lower Limb Muscle Activity During Relevé Descending Phase Comparing Flat Shoes and Pointe Shoes.

AIMS: In classical ballet, dancers may wear flat shoes and pointe shoes. To consider the kinematic changes between flat shoes and pointe shoes to prevent injuries, it is essential to focus on the fundamental ballet movement of standing on pointe. This study aimed to clarify the differences in the center of pressure (COP) displacement and lower limb muscle activity during the descending phase of a relevé when wearing pointe shoes versus flat shoes. METHODS: Ten amateur ballet dancers volunteered for this study and performed a reléve wearing flat shoes and pointe shoes. We measured the COP displacement by using a footplate and electromyographies of the tibialis anterior, soleus, lateral gastrocnemius, and peroneus longus muscles during the relevé descending phase. These data were compared using a paired t-test or Wilcoxon signed-rank sum test. RESULTS: The COP significantly shifted to the lateral side when dancers were wearing pointe shoes compared to wearing flat shoes (p<0.05). The muscle activity of the tibialis anterior and soleus muscles was significantly higher by 5.7% and 5.3%, respectively, when ballet dancers were wearing pointe shoes compared to flat shoes (p<0.05). However, there were no differences in both lateral gastrocnemius and peroneus longus. CONCLUSION: Greater muscle activities in the tibialis anterior and soleus muscles when wearing pointe shoes than when wearing flat shoes were associated with a larger lateral displacement of the COP. To control the COP displacement during the descending phase of a relevé, the muscle activity of the peroneus longus, which is antagonist of tibialis anterior muscle, and soleus muscles should be increased.

Dance as a neurorehabilitation strategy: A systematic review.

OBJECTIVE: This systematic review aimed to demonstrate the benefits of dance-based therapeutic interventions in rehabilitation processes in patients with neurological disorders. METHODS: Searches on the following databases and electronic search engines were conducted: MEDLINE, LILACS, Science Direct, SCOPUS, PeDro, BVS (virtual health library), and Google Scholar. Data extraction was independently performed by two authors. Twenty-five clinical trial-type studies that included dance and established outcome measures were included, and studies in which a musicalized exercise modality was used without the connotation of dance were excluded. RESULTS: From the results of multiple studies, the short-term motor benefits of rhythmic auditory stimulation on gait parameters were highlighted. Furthermore, there was scientific evidence demonstrating the benefits of the cognitive and social parameters of group dancing as significant improvements in cognitive flexibility and processing speed were highlighted. Recent studies showed that interventions based on exercise and/or rhythmic choreography can reduce the risk of falls in patients with neurological disorders, thereby improving their quality of life. CONCLUSION: These findings suggest that dance is an innovative and effective method that can be included in therapies as it allows for a promising prognosis in motor, cognitive, and social performances of patients with neurological disorders that alter mobility and quality of life.