An Exploration of Low Back Beliefs of Male Pre-Professional and Professional Dancers.

BACKGROUND: Globally, male dancers are affected by low back pain (LBP) up to 2.5 times more than female dancers. While female dancers' beliefs around LBP and dance-specific low back movements exist, no research has explored male dancers' beliefs. This study aimed to (1) examine the low back beliefs of Australian male professional and pre-professional dancers, and (2) determine if beliefs toward common low back movements and lifting differed when current LBP or history of disabling LBP (DLBP) were considered. METHODS: 40 male dancers (mean age [SD] 26.9 years [7.9]) from a range of dance backgrounds (all participating in ballet) were recruited to complete a cross-sectional survey comprising a beliefs questionnaire considering dance-specific movement and lifting tasks, the Back Pain Attitudes Questionnaire (Back-PAQ) and the Athletic Fear Avoidance Questionnaire (AFAQ). Primary analysis included initial descriptives, a repeated measures ANOVA for movement-specific beliefs and visual thematic analysis for written responses within the belief's questionnaire. Secondary subgroup analysis included independent T-tests for those with/without current LBP and those with/without a history of DLBP. RESULTS: Fourteen dancers reported current LBP and 30 reported a history of DLBP. Dancers held generally negative beliefs toward the low back (Back-PAQ mean 123.1 ± 9.7) with neither subgroup demonstrating significant between-group difference (P < .05). Dance-specific flexion movements were seen as safer than extension movements (P < .05), and more extended-spine lifting was seen as safer than more flexed-spine lifting (P < .05). Dancers experiencing current LBP held less positive beliefs surrounding some dance-specific movements. CONCLUSIONS: Dancers hold negative general beliefs toward the low back irrespective of current or historical DLBP, however their beliefs surrounding dance-specific movements were relatively positive. Dancers' beliefs surrounding some movements were affected by the presence of current LBP, in particular an arabesque and a fish dive.

Timing is everything, but does it really matter? Impact of 8-weeks morning versus evening iron supplementation in ballet and contemporary dancers.

ABSTRACTThe effectiveness of a morning versus evening oral iron supplement strategy to increase iron stores was explored. Ballet and contemporary dancers with serum ferritin (sFer) < 50µg/L (n = 14), were supplemented daily with 105 mg elemental oral iron in either the morning (FeAM) or evening (FePM) for 8 weeks. A control group (n = 6) with sFer >50µg/L were given no supplement over the same period. Dancers' sFer were measured at baseline and post-intervention. Assessment of daily training load, dietary intake, and menstruation were made. A significant interaction (p < 0.001) showed the within group sFer change over the 8-week intervention in FeAM (+25.9 ± 10.5µg/L) and FePM, (+22.3 ± 13.6µg/L) was significantly different to CON (-30.17 ± 28.7µg/L; both p = 0.001). This change was not different between FeAM and FePM (p = 0.778). sFer levels within FeAM and FePM significantly increased over the 8-weeks; however, they significantly decreased in the CON group (all p < 0.05). Post-intervention sFer levels were no longer different between the three groups (p > 0.05). Training load, dietary intake, and number of menstrual cycles incurred were similar between FeAM and FePM (p > 0.05). Oral iron supplementation in either the morning or evening appears equally effective in increasing sFer levels in dancers with sub-optimal iron status.

8 weeks of oral iron supplements increases serum ferritin levels in elite dancers.Dancers not consuming an iron supplement showed a decline in serum ferritin over the 8-week period.Consuming the iron supplement in either the morning or the evening appeared equally effective in improving serum ferritin stores.

Paramedic training, experience, and confidence with out-of-hospital childbirth (OOHB) in Australia.

BACKGROUND: Out-of-hospital births (OOHBs) are rare representing ∼0.05% of prehospital callouts. OOHBs are at increased risk of complications including life-threatening conditions such as postpartum haemorrhage and neonate resuscitation. This research investigated Australian paramedics perceptions of' training, experience, and confidence with OOHBs. METHODS: Semi-structured qualitative interviews were undertaken in late 2021 via online conference or face-to-face. Sessions were audio-recorded and transcribed. Data was analysed and coded into over-arching themes using thematic analysis. RESULTS: Fourteen participants were interviewed from military, industrial, and jurisdictional ambulance services. Nine participants were female, and experience ranged from 1.5 to 20 years. Six Australian states were represented, incorporating rural and metropolitan regions. Participants reported sporadic or infrequent training. No participant had exposure to OOHBs during their undergraduate degree, with the most experienced paramedic only attending six births. Participants with little/no experience reported low confidence, and even more experienced participants reported anxiety when attending OOHBs, particularly if there were long distances to definitive care or potential complications. CONCLUSION: Many paramedics expressed low confidence and high anxiety regarding OOHBs, especially regarding complications. Many felt insufficient time was dedicated to OOHBs during education and training. This has the capacity to impact on patient care and outcomes.

Developing an alcohol and other drug serious game for adolescents: considerations for improving student engagement.

OBJECTIVES: To explore perceptions of alcohol and other drug (AOD) education and digital game design preferences among Australian adolescents with the goal of identifying key factors to promote engagement in an AOD serious game for Australian secondary school students. METHODS: Semi-structured focus groups were conducted with 36 adolescents aged between 13 and 18 years. Qualitative data was analysed using thematic analysis. RESULTS: Participants described heightened engagement with AOD education that incorporated relatable and relevant real-life stories and interactive discussions. They also expressed a desire for learning to focus on practical strategies to reduce AOD harm and overcome social pressure to use AOD. Participants highlighted the importance of incorporating relatable characters and context-relevant scenarios in promoting engagement, and identified social elements, player choice, and optimal challenge as important game design considerations. CONCLUSIONS: A focus on meaningful realistic scenarios, relatable characters, relevant information and practical skills may promote high school aged students' engagement with AOD educational content. Game designs incorporating social elements and decision-making opportunities may be conducive to promoting engagement and enhancing learning. IMPLICATIONS FOR PUBLIC HEALTH: Findings from this study can be used by researchers and game designers for the development of future AOD serious games targeted at Australian adolescents.

Dietary Iron and the Elite Dancer.

Dancers are an athlete population at high risk of developing iron deficiency (ID). The aesthetic nature of the discipline means dancers potentially utilise dietary restriction to meet physique goals. In combination with high training demands, this means dancers are susceptible to problems related to low energy availability (LEA), which impacts nutrient intake. In the presence of LEA, ID is common because of a reduced mineral content within the low energy diet. Left untreated, ID becomes an issue that results in fatigue, reduced aerobic work capacity, and ultimately, iron deficient anaemia (IDA). Such progression can be detrimental to a dancer's capacity given the physically demanding nature of training, rehearsal, and performances. Previous literature has focused on the manifestation and treatment of ID primarily in the context of endurance athletes; however, a dance-specific context addressing the interplay between dance training and performance, LEA and ID is essential for practitioners working in this space. By consolidating findings from identified studies of dancers and other relevant athlete groups, this review explores causal factors of ID and potential treatment strategies for dancers to optimise absorption from an oral iron supplementation regime to adequately support health and performance.

Out-of-hospital births and the experiences of emergency ambulance clinicians and birthing parents: a scoping review protocol.

INTRODUCTION: Emergency ambulance clinicians attend a wide range of prehospital emergencies, including out-of-hospital births (OOHBs). Intrapartum care comprises approximately 0.05% of emergency medical services' caseload, with only ~10% of intrapartum cases progressing to birth in emergency ambulance clinician care. However, this low exposure rate potentially allows obstetric clinical skills and knowledge to decay, which may impact on patient care. Additionally, unplanned OOHBs are known to have a higher incidence of complications and adverse outcomes than their counterparts born in hospital, such as postpartum haemorrhage or hypothermia. This scoping review will explore OOHBs and associated complications in emergency ambulance clinician care, investigate birth parent, significant partner and clinician experiences regarding OOHBs, and consider barriers and challenges to optimal patient care, to identify future research opportunities and associated knowledge gaps for this patient cohort. METHODS AND ANALYSIS: This scoping review will follow the nine-step methodological framework suggested by the Joanna Briggs Institute and use the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. Five electronic databases (MEDLINE via EBSCO, CINAHL, Embase, Web of Science and Wiley Online) will be searched to identify articles for inclusion. The 'participant, concept, context' criteria will be used to identify suitable search words regarding OOHBs in emergency ambulance clinician care. The review will include peer-reviewed and preprint literature. Two reviewers will independently assess articles based on title and abstract for inclusion in the review. Data will be charted using a data extraction tool for consistency and provide a succinct descriptive summary of the results. ETHICS AND DISSEMINATION: This study does not require ethical review as all the information obtained will come from publicly available resources. Results will be disseminated via a peer-reviewed publication. This scoping review is preregistered with the Open Science Framework (https://osf.io/ta35q).

Movement quantity and quality: How do they relate to pain and disability in dancers?

OBJECTIVE: This field-based study aimed to determine the association between pre-professional student dancers' movement quantity and quality with (i) pain severity and (ii) pain related disability. METHODS: Pre-professional female ballet and contemporary dance students (n = 52) participated in 4 time points of data collection over a 12-week university semester. At each time point dancers provided self-reported pain outcomes (Numerical Rating Scale as a measure of pain severity and Patient Specific Functional Scale as a measure of pain related disability) and wore a wearable sensor system. This system combined wearable sensors with previously developed machine learning models capable of capturing movement quantity and quality outcomes. A series of linear mixed models were applied to determine if there was an association between dancers' movement quantity and quality over the 4 time points with pain severity and pain related disability. RESULTS: Almost all dancers (n = 50) experienced pain, and half of the dancers experienced disabling pain (n = 26). Significant associations were evident for pain related disability and movement quantity and quality variables. Specifically, greater pain related disability was associated with more light activity, fewer leg lifts to the front, a shorter average duration of leg lifts to the front and fewer total leg lifts. Greater pain related disability was also associated with higher thigh elevation angles to the side. There was no evidence for associations between movement quantity and quality variables and pain severity. DISCUSSION: Despite a high prevalence of musculoskeletal pain, dancers' levels of pain severity and disability were generally low. Between-person level associations were identified between dancers' movement quantity and quality, and pain related disability. These findings may reflect dancers' adaptations to pain related disability, while they continue to dance. This proof-of-concept research provides a compelling model for future work exploring dancers' pain using field-based, serial data collection.

Development of a Machine Learning Model for the Estimation of Hip and Lumbar Angles in Ballet Dancers.

OBJECTIVE: Accurate field-based assessment of dance kinematics is important to understand the etiology, and thus prevention and management, of hip and back pain. The study objective was to develop a machine learning model to estimate thigh elevation and lumbar sagittal plane angles during ballet leg lifting tasks, using wearable sensor data. METHODS: Female dancers (n=30) performed ballet-specific leg lifting tasks to the front, side, and behind the body. Dancers wore six wearable sensors (100 Hz). Data were simultaneously collected using an 18-camera motion analysis system (250 Hz). Due to synchronization and hardware malfunction issues, only 23 dancers had usable data. Using leave-one-out cross-validation, machine learning models were compared with the optic motion capture system using root mean square error (RMSE) in degrees and correlation coefficients (r) over the complete movement profile of each leg lift and mean absolute error (MAE) and Bland Altman plots for peak angle accuracy. RESULTS: The average RMSE for model estimation was 6.8° for thigh elevation angle and 5.6° for lumbar spine sagittal plane angle, with respective MAE of 6.3°and 5.7°. There was a strong correlation between the machine learning model and optic motion capture for peak angle values (thigh r=0.86, lumbar r=0.96). CONCLUSION: The models developed demonstrated an acceptable degree of accuracy for the estimation of thigh elevation angle and lumbar spine sagittal plane angle during dance-specific leg lifting tasks. This provides potential for a near-real-time, field-based measurement system.

Judges' evaluation reliability changes between identifiable and anonymous performance of hip-hop dance movements.

Hip-hop competitions are performed across the world. In the recent inclusion in the 2018 Youth Olympic Games, the assessment of hip-hop performance is undertaken by a panel of judges. The purpose of this study was to determine the reliability of different visualisation tools utilised in the assessment of the hip-hop dance movements. Ten dancers performed basic rhythmic hip-hop movements which were captured using a motion capture system and video camera. Humanoid and stick figure animations of the dancers' movements were created from the motion capture data. Ten judges then assessed 20 dance trials through observation using three different visualisation tools on a computer display, each of which provided different representations of a given hip-hop performance: (1) the actual video of the dancers; (2) an anonymous stick figure animation; (3) an anonymous humanoid animation. Judges were not informed that they were repeating an assessment of the performances across the three visualisation tools. The humanoid animation demonstrated the highest inter-class correlation coefficients among the three methods. Despite the stick figure animation demonstrating moderate to high reliability, both the humanoid animation and the video demonstrated very high reliability in the intra-class correlation coefficient. It is recommended that further research is undertaken exploring the use of humanoid animation as a formative assessment tool in the evaluation of hip-hop dance and the evolution of hip-hop into a respected artistic athletic discipline.

Dancers' Joint Strategies for Achieving Turnout in Low and High Friction Conditions.

BACKGROUND: Dancing with legs externally rotated (turnout) is a fundamental element of ballet technique. A reliance on floor friction to achieve turnout may contribute toward the high injury rate in dancers. Joint strategies used by dancers in high and low friction turnout conditions are not well understood. OBJECTIVES: To quantify the lower limb and lumbar spine joint strategies used by female pre-professional dancers to achieve turnout in low-friction (rotation discs) and high-friction (functional and forced) conditions. METHODS: Twenty-three pre-professional female dancers participated in the study. A 12-camera motion analysis system collected hip and knee external rotation (ER), ankle abduction, and lumbar extension angles in three turnout conditions and passive hip ER range of motion angles. Repeated measures ANOVA analysed the differences between joint angles, maximum turnout angle (foot relative to pelvis), and available hip ER. RESULTS: Dancers demonstrated lower knee ER (18.5±4.8°) and ankle abduction (6.0±7.7°) angles during low-friction turnout compared to higher friction conditions (p<0.05). Dancers utilised between 70-83% of available hip ER within all conditions. Low-friction turnout demonstrated greater hip ER contribution within maximum turnout (43%) compared to higher friction conditions. Dancers demonstrated greater lumbar extension angles in low-friction turnout compared to higher friction conditions (p<0.05). CONCLUSIONS: Further hip ER strength training is required to promote greater hip ER range within the position. Rotation discs may be a valuable training tool as dancers demonstrated greater hip ER utilisation with less knee ER and ankle abduction; however, this position did promote undesirable lumbar extension.

An Exploration of Machine-Learning Estimation of Ground Reaction Force from Wearable Sensor Data.

This study aimed to develop a wearable sensor system, using machine-learning models, capable of accurately estimating peak ground reaction force (GRF) during ballet jumps in the field. Female dancers (n = 30) performed a series of bilateral and unilateral ballet jumps. Dancers wore six ActiGraph Link wearable sensors (100 Hz). Data were collected simultaneously from two AMTI force platforms and synchronised with the ActiGraph data. Due to sensor hardware malfunctions and synchronisation issues, a multistage approach to model development, using a reduced data set, was taken. Using data from the 14 dancers with complete multi-sensor synchronised data, the best single sensor was determined. Subsequently, the best single sensor model was refined and validated using all available data for that sensor (23 dancers). Root mean square error (RMSE) in body weight (BW) and correlation coefficients (r) were used to assess the GRF profile, and Bland-Altman plots were used to assess model peak GRF accuracy. The model based on sacrum data was the most accurate single sensor model (unilateral landings: RMSE = 0.24 BW, r = 0.95; bilateral landings: RMSE = 0.21 BW, r = 0.98) with the refined model still showing good accuracy (unilateral: RMSE = 0.42 BW, r = 0.80; bilateral: RMSE = 0.39 BW, r = 0.92). Machine-learning models applied to wearable sensor data can provide a field-based system for GRF estimation during ballet jumps.

Development of a Human Activity Recognition System for Ballet Tasks.

BACKGROUND: Accurate and detailed measurement of a dancer's training volume is a key requirement to understanding the relationship between a dancer's pain and training volume. Currently, no system capable of quantifying a dancer's training volume, with respect to specific movement activities, exists. The application of machine learning models to wearable sensor data for human activity recognition in sport has previously been applied to cricket, tennis and rugby. Thus, the purpose of this study was to develop a human activity recognition system using wearable sensor data to accurately identify key ballet movements (jumping and lifting the leg). Our primary objective was to determine if machine learning can accurately identify key ballet movements during dance training. The secondary objective was to determine the influence of the location and number of sensors on accuracy. RESULTS: Convolutional neural networks were applied to develop two models for every combination of six sensors (6, 5, 4, 3, etc.) with and without the inclusion of transition movements. At the first level of classification, including data from all sensors, without transitions, the model performed with 97.8% accuracy. The degree of accuracy reduced at the second (83.0%) and third (75.1%) levels of classification. The degree of accuracy reduced with inclusion of transitions, reduction in the number of sensors and various sensor combinations. CONCLUSION: The models developed were robust enough to identify jumping and leg lifting tasks in real-world exposures in dancers. The system provides a novel method for measuring dancer training volume through quantification of specific movement tasks. Such a system can be used to further understand the relationship between dancers' pain and training volume and for athlete monitoring systems. Further, this provides a proof of concept which can be easily translated to other lower limb dominant sporting activities.

Virtual Reality Triage Training Can Provide Comparable Simulation Efficacy for Paramedicine Students Compared to Live Simulation-Based Scenarios.

Background: Mass-casualty incidents (MCIs) are catastrophic. Whether they arise from natural or man-made disasters, the nature of such incidents and the multiple casualties involved can rapidly overwhelm response personnel. Mass-casualty triage training is traditionally taught via either didactic lectures or table top exercises. This training fails to provide an opportunity for practical application or experiential learning in immersive conditions. Further, large-scale simulations are heavily resource-intensive, logistically challenging, require the coordination and time of multiple personnel, and are costly to replicate. This study compared the simulation efficacy of a bespoke virtual-reality (VR) MCI simulation with an equivalent live simulation scenario designed for undergraduate paramedicine students. Methods: Both simulations involved ten injured patients resulting from a police car chase and shooting. Twenty-nine second-year paramedicine students completed the live and VR simulation in a random order. The training efficacy of the VR and live simulation was evaluated with respect to student immersion and task-difficulty, clinical decision-making (i.e. triage card allocation accuracy and timeliness), learning satisfaction, and cost of delivery. Results: While perceived physical demand was higher in the live simulation compared to VR (p < 0.001), no differences were observed across mental demand, temporal demand, performance, effort or frustration domains. No differences were found for participant satisfaction across the two platforms. No differences were observed in the number of triage cards correctly allocated to patients in each platform. However, participants were able to allocate cards far quicker in VR (p < .001). Cost of running the VR came to AUD $712.04 (staff time), compared to the live simulations which came to AUD $9,413.71 (staff time, moulage, actors, director, prop vehicle), approximately 13 times more expensive. Conclusion: The VR simulation provided near identical simulation efficacy for paramedicine students compared to the live simulation. VR MCI training resources represent an exciting new direction for authentic and cost-effective education and training for medical professionals.

An Exploration of Pre-Professional Dancers' Beliefs of the Low Back and Dance-Specific Low Back Movements.

OBJECTIVE: Low back pain (LBP) is common in dancers. A biopsychosocial model should be considered in the aetiology of LBP, including a dancer's general beliefs of the low back and movements of the spine. This study aimed to determine pre-professional dancers' beliefs about their lower back in general and dance-specific movements of the spine and to explore whether these beliefs were influenced by a history of disabling LBP. METHODS: 52 pre-professional female dancers (mean age 18.3 [1.4] yrs) were recruited and reported whether they had a history of disabling LBP and completed the Back Pain Attitudes Questionnaire (Back-PAQ) and a dance movement beliefs questionnaire. A linear mixed model was applied to determine the effect of a history of disabling LBP on dancers' beliefs (p<0.05). RESULTS: 20 dancers reported a history of disabling LBP. Regardless of this LBP history, dancers held generally negative beliefs as measured by the Back-PAQ (p=0.130). A history of disabling LBP did not influence dancers' perceived movement safety of all tasks (p=0.867), and dancers held negative beliefs towards extension activities. These beliefs were linked to the conceptions of perceived risk of damage and the need to protect the lower back. CONCLUSIONS: Dancers hold negative general beliefs around the low back and low back movements, regardless of a history of disabling LBP. Dancers perceive extension activities as more dangerous than flexion activities. These beliefs may reflect a combination of pain experience and beliefs specific to dance.

An analysis of the foot in turnout using a dance specific 3D multi-segment foot model.

INTRODUCTION: Recent three-dimensional (3D) kinematic research has revealed foot abduction is the strongest predictor of standing functional and forced turnout postures. However, it is still unknown how the internal foot joints enable a large degree of foot abduction in turnout. The primary purpose of this study was to use a dance specific multi-segment foot model to determine the lower leg and foot contributions to turnout that female university-level ballets use to accentuate their turnout. METHODS: Eighteen female dance students (mean age, 18.8 ± 1.6 years) volunteered for this study. Retro-reflective markers were attached to the dancers' dominant foot. Each dancer performed three repetitions of functional turnout, forced turnout and ten consecutive sautés in first position. Repeated measures ANOVA with Bonferroni adjustments for the multiple comparisons were used to determine the kinematic adjustments, hindfoot eversion, midfoot and forefoot abduction, navicular drop (i.e. lowering of the medial longitudinal arch) and first metatarsophalangeal joint abduction between natural double leg up-right posture and the first position conditions. RESULTS: Hindfoot eversion (4.6°, p < 0.001) and midfoot abduction (2.8°, p < 0.001) significantly increased in functional turnout compared to the natural double leg up-right posture. Thirteen dancers demonstrated increased first metatarsophalangeal joint (MTPJ) abduction in forced turnout, however no statistically significant increase was found. Navicular drop during sautés in first position significantly increased by 11 mm (p < 0.001) compared to the natural double leg up-right posture. CONCLUSION: Our findings suggest dancers do pronate, via hindfoot eversion and midfoot abduction in both functional and forced turnout, however, no immediate association was found between forced turnout and first MTPJ abduction. Foot pronation does play a role in achieving turnout. Further prospective research on in situ measures of the lower limb in turnout and injury surveillance is required to improve our understanding of the normal and abnormal dance biomechanics.

Ankle taping can reduce external ankle joint moments during drop landings on a tilted surface.

Ankle taping is commonly used to prevent ankle sprains. However, kinematic assessments investigating the biomechanical effects of ankle taping have provided inconclusive results. This study aimed to determine the effect of ankle taping on the external ankle joint moments during a drop landing on a tilted surface at 25°. Twenty-five participants performed landings on a tilted force platform that caused ankle inversion with and without ankle taping. Landing kinematics were captured using a motion capture system. External ankle inversion moment, the angular impulse due to the medio-lateral and vertical components of ground reaction force (GRF) and their moment arm lengths about the ankle joint were analysed. The foot plantar inclination relative to the ground was assessed. In the taping condition, the foot plantar inclination and ankle inversion angular impulse were reduced significantly compared to that of the control. The only component of the external inversion moment to change significantly in the taped condition was a shortened medio-lateral GRF moment arm length. It can be assumed that the ankle taping altered the foot plantar inclination relative to the ground, thereby shortening the moment arm of medio-lateral GRF that resulted in the reduced ankle inversion angular impulse.

The prevalence of generalized and syndromic hypermobility in elite Australian dancers.

OBJECTIVES: To determine the prevalence of Generalized Joint Hypermobility (GJH) and Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobility Type (JHS/EDS-HT) among dancers using established validated measures. DESIGN: Observational Cohort Study. SETTING: Laboratory. PARTICIPANTS: 85 dancers from two dance institutions. MAIN OUTCOME MEASURES: GJH was determined using the Beighton score (cut-point ≥5/9) and the Lower Limb Assessment Scale (LLAS) (cut-point ≥7/12). Presence of JHS/EDS-HT was assessed using the Brighton and Villefranche criteria. Paired sample t-test was performed to compare LLAS side-to-side scores, and percentage disagreements calculated to determine differences between the two GJH and the two JHS/EDS-HT measures. RESULTS: 72% of dancers met the Beighton cut-point for GJH, while 38% and 42% met the LLAS cut-point on the left and right respectively. The proportion of dancers identified with GJH was different when assessed using the Beighton compared to the left and right LLAS (both p < 0.001), a disagreement of 48% and 46% respectively, with Beighton classifying more participants as having GJH. The Villefranche identified more dancers with JHS/EDS-HT than the Brighton (84% vs 31%, p < 0.001), with 54% disagreement. CONCLUSIONS: High prevalence of generalized and syndromic hypermobility was found regardless of the criteria used. A higher Beighton cut-point, e.g. ≥6/9, to identify true GJH amongst dancers maybe warranted.

Lower leg and foot contributions to turnout in female pre-professional dancers: A 3D kinematic analysis.

Turnout is a central element of classical ballet which involves sustained external rotation of the lower limbs during dance movements. Lower leg and foot compensation mechanisms which are often used to increase turnout have been attributed to the high incidence of lower limb injury in dancers. Evaluation of dancers' leg posture is needed to provide insight into the lower limb kinematic strategies used to achieve turnout. The primary purpose of this study was to use 3D kinematic analyses to determine the lower leg and foot compensations that are incorporated by female university dancers to accentuate their turnout. Active and passive external tibiofemoral rotation (TFR) was also measured. A moderate-strong negative relationship was observed between hip external rotation (HER) and foot abduction in the three first position conditions. A moderate negative relationship was found between passive TFR and foot abduction in all first position conditions. Our findings suggest dancers are more likely to pronate, than rotate the knee to compensate for limited HER. Dancers with a limited capacity to pronate may force additional rotation via the knee. Ongoing research would benefit from more in-depth analyses of the foot/ankle complex using a multi-segment foot model.

Kinematic repeatability of a multi-segment foot model for dance.

The purpose of this study was to determine the intra and inter-assessor repeatability of a modified Rizzoli Foot Model for analysing the foot kinematics of ballet dancers. Six university-level ballet dancers performed the movements; parallel stance, turnout plié, turnout stance, turnout rise and flex-point-flex. The three-dimensional (3D) position of individual reflective markers and marker triads was used to model the movement of the dancers' tibia, entire foot, hindfoot, midfoot, forefoot and hallux. Intra and inter-assessor reliability demonstrated excellent (ICC ≥ 0.75) repeatability for the first metatarsophalangeal joint in the sagittal plane. Intra-assessor reliability demonstrated excellent (ICC ≥ 0.75) repeatability during flex-point-flex across all inter-segmental angles except for the tibia-hindfoot and hindfoot-midfoot frontal planes. Inter-assessor repeatability ranged from poor to excellent (0.5 > ICC ≥ 0.75) for the 3D segment rotations. The most repeatable measure was the tibia-foot dorsiflexion/plantar flexion articulation whereas the least repeatable measure was the hindfoot-midfoot adduction/abduction articulation. The variation found in the inter-assessor results is likely due to inconsistencies in marker placement. This 3D dance specific multi-segment foot model provides insight into which kinematic measures can be reliably used to ascertain in vivo technical errors and/or biomechanical abnormalities in a dancer's foot motion.

Identifying lower limb specific and generalised joint hypermobility in adults: validation of the Lower Limb Assessment Score.

BACKGROUND: The Lower Limb Assessment Score (LLAS) has only been validated in a paediatric population. The aim of this study was to validate the use of the LLAS in an adult population by: i) evaluating its ability to discriminate between different extents of lower limb hypermobility, ii) establishing a cut-off score to identify lower limb hypermobility, and iii) determining if the LLAS is able to identify Generalised Joint Hypermobility (GJH). METHODS: Participants were recruited across three groups representing varying degrees of hypermobility. They were assessed using the LLAS, Beighton score and clinical opinion. Pearson's correlation coefficient and MANOVA were used to assess between-group differences in the LLAS. The cut-off score was determined using median and inter-quartile ranges and the Receiver Operator Characteristic Curve. The ability of the LLAS to identify GJH was assessed using percent agreement with clinical opinion. RESULTS: One hundred twelve participants aged 18-40 years were recruited. The LLAS distinguished the control from the likely hypermobile and known hypermobile cohorts (both p < 0.001), as well as the likely hypermobile from the known hypermobile cohort (p = 0.003). The LLAS cut-off score for identifying lower limb hypermobility was ≥7/12 with a specificity of 86% and sensitivity of 68%. The LLAS accurately identified those with GJH with high percentage agreement compared to clinical opinion across all cohorts (69-98%). CONCLUSIONS: The LLAS is a valid tool for identifying lower limb specific hypermobility and GJH in adults at a cut-off score of ≥7/12. It demonstrates excellent specificity and moderate sensitivity, and discriminates well between extents of hypermobility.