Sensory Organization Determinants of Postural Stability in Trained Ballet Dancers

The Development and Reliability of an Updated Dance-Specific Star Excursion Balance Test Protocol

Background: While the previous research has made crucial developments in a dance-specific version of the SEBT, current modifications to the SEBT have not conclusively produced a valid dance-specific dynamic balance test. Purpose: The aim of this paper was to utilize the most practical dance-specific variations from previous research and incorporate them into a reliable test to be considered for future screenings for dancers. Methods: Twenty-one female dancers voluntarily took part in the research (age: 20.86 ± 3.68 years). This protocol consists of 3 stages, each increasing in difficulty; stage one: dsSEBT Average Tempo, stage two: dsSEBT Block, and stage three: a combination of stage 1 and stage 2, the dsSEBT Average Tempo on Block. Reach distance (% of limb length), error scores, and average time to complete each stage were recorded. A stage completion criteria was developed to move from one stage to the next wherein certain reach distance and error score standards needed to be met. Results: Between previous research using the same participants and the current study, each reach direction exhibits a statistically significant correlation (P < .05) with good to excellent ICC values ranging from .750 to .918, suggesting that test-retest reliability is high. Overall, 90.48% of participants succeeded in passing stage one, 19.05% of total participants passed stage two, and only 4.76% of the 21 participants passed all 3 stages with statistically significant differences detected for reach distance and incomplete trials between stages (P < .05). Conclusion: This data suggests that the test is challenging enough to show dancers weaknesses and push the limits of their balance capabilities. With a clear increase in difficulty from stage to stage, the test adds layers of demanding tasks designed to test the dancer proprioceptively.

Assessment of Dynamic Balancing Performance of Synchronized Ice Skaters With Sudden Provocation Test via Principal Component Analysis

Background: Balancing performance can be affected by regular and high-level athletic training, which has not been fully explored in synchronized ice skaters. This study aimed to analyze the dynamic balancing performance by assessing the principal and compensatory movements performed during the sudden provocation tests and evaluating the parameters that characterize the platform’s motion. Method: Twelve young female synchronized ice skaters and 12 female age-matched controls participated. Sudden provocation tests were completed three times in bipedal stance and in single-leg stances, and sport-specific fatigue session was inserted between the repetitions. Results: Significantly more time was necessary to recover balance for both groups after the fatiguing sessions (p < .05). Interestingly, skaters performed less effectively in the simplest condition (bipedal stance) than the control group (p < .05). The principal component analysis showed that the first principal movement was the same for both groups. The skater group used the upper body and arms more often to compensate, while the control group’s recovery strategy consisted mainly of abduction of the elevated leg. The damping ratio and the relative variance of the first principal movement showed a negative correlation (p < .05), suggesting that those with superior balancing effectiveness recruited more compensatory movements.

Effect of Integrated Training on Balance and Ankle Reposition Sense in Ballet Dancers

OBJECTIVE

To investigate the effects of a 6-week integrated training program on the ankle joint reposition sense and postural stability in ballet dancers.

METHODS

Sixteen female ballet dancers participated in the study and underwent a 6-week integrated training program consisting of plyometric, proprioception and core stability exercises along with a home program involving additional ankle muscle strengthening and stretching. The ankle joint reposition tests and the parameters of the center of pressure (COP) while performing grand-plie (deep squatting) and releve en demi-pointe (standing on balls of foot) movements were measured before and after training.

RESULTS

After 6 weeks, participants showed significantly smaller absolute ankle joint reposition errors in dorsiflexion (p = 0.031), plantarflexion (p = 0.003) and eversion (p = 0.019) compared to the pre-training measurement. Furthermore, after training, a significantly slower average COP speed at pre-equilibrium during grand-plie movement (p = 0.003) and pre-equilibrium phase of releve en demi-pointe (p = 0.023) were observed. In addition, the maximum COP displacement in the medial-lateral direction was significantly smaller at pre-equilibrium phase during grand-plie (p = 0.044) and releve en demi-pointe movements (p = 0.004) after training.

CONCLUSIONS

The 6-week integrated training program improved the ankle joint reposition sense and postural control in the medial-lateral direction during grand-plie and releve en demi-pointe movements.

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.

Comparison of Static and Dynamic Balance at Different Levels of Sport Competition in Professional and Junior Elite Soccer Players

Jadczak, Ł, Grygorowicz, M, Dzudziński, W, and Śliwowski, R. Comparison of static and dynamic balance at different levels of sport competition in professional and junior elite soccer players. J Strength Cond Res 33(12): 3384-3391, 2019-The purpose of this study was to compare body balance control and balance recovery strategies of professional football players, representing various sports levels in static (eyes open, eyes closed) and dynamic conditions, both on the dominant and nondominant leg. Three groups of professional and junior elite soccer players were investigated: a PRO group (n = 52), a U-21 group (n = 55), and a U-19 group (n = 47). The study of body balance control was performed using a Delos Postural Proprioceptive System measurement tool. The analysis of the results showed an effect of group (p < 0.01) and leg significance (p < 0.95) in the dynamic test. Three-way analysis of variance (3 [group] × 2 [leg] × 2 [eyes]) of static test data showed that the main effect of eyes (p < 0.0001), group (p < 0.0001), and leg (p = 0.0092) and the 2-way interaction of eyes × group (p = 0.0003) were significant. To represent statistical significance, the cutoff value was set to be p ≤ 0.005 for all measures. Our results indicate the importance of evaluation and monitoring of dynamic and static balance on both legs, which allows for a comprehensive comparison of body balance control and the balance recovery strategy depending on the represented sport level. Our study indicates that the higher the sport level of football players (the PRO group), the better their balance, which may indirectly contribute to the prevention of injuries and more effective performance of any actions directly related to the game.

The relationship between the functional movement screen, star excursion balance test and the Beighton score in dancers

Objectives: To determine the association between the Functional Movement Screen (FMS), Star Excursion Balance Test (SEBT) and the Beighton Score (BS) in dancers with implications for performance and injury.Methods: The study was of cross-sectional design and included 47 female university dancers (age: 20.4 ± 0.7 years, height: 160.5 ± 5.8 cm; mass: 55.6 ± 4.8 kg). Participants completed the FMS and the anterior, posteromedial and posterolateral reach components of the SEBT and hypermobility was assessed via the BS.Results: A fair significant correlation existed between FMS composite and total BS (r = 0.37, p = 0.01). For individual elements of the screening tools, there were 24 significant correlations between the FMS and the BS, 11 significant correlations between the FMS and SEBT and 4 significant correlations between the SEBT and BS.Conclusion: The FMS and the BS correlations highlighted the importance of the deep squat in functional movement and the relationship between FMS mobility elements and the BS. The significant correlation between the FMS and the BS may suggest that they capture similar information. The active straight leg raise and shoulder mobility measurements should be considered key elements to measure during screening.

Joint Hypermobility as a Predictor of Mechanical Loading in Dancers

CONTEXT

Dance requires the performance of complex movements that may exceed normal anatomical range. However, in hypermobile individuals, this may have implications for injury and performance.

OBJECTIVES

The aim of the study was to investigate the efficacy of the Beighton score (BS) in predicting mechanical loading in dancers in hypermobile and nonhypermobile dancers with consideration of accelerometer placement and lumbar flexion hypermobility.

DESIGN

Cohort study, clinical measurement.

SETTING

University.

PARTICIPANTS

A total of 34 dancers had their joint hypermobility assessed by the BS. Participants completed the Dance Aerobic Fitness Test with a global positioning device incorporating a triaxial accelerometer located at the cervico-thoracic junction (C7) and one at the midbelly of the gastrocnemius.

MAIN OUTCOME MEASURES

Accelerometry data were used to calculate PlayerLoad total, PlayerLoad medial-lateral, PlayerLoad anterior-posterior, and PlayerLoad vertical. Physiological response was measured via heart rate and fatigue response by rate of perceived exertion.

RESULTS

The total BS was a poor predictor of all mechanical loading directions with PlayerLoad anterior-posterior C7 (r = .15) and PlayerLoad total lower limb (r = .20) the highest values. Multiple linear regression was a better predictor with values of C7 (r = .43) and lower limb (r = .37). No significant difference existed between hypermobile and nonhypermobile subjects for mechanical loading values for all stages of the Dance Aerobic Fitness Test and for heart rate and fatigue responses.

CONCLUSIONS

The BS is not a good predictor of mechanical loading which is similar in hypermobile and nonhypermobile dancers for all levels of the Dance Aerobic Fitness Test. Mechanical loading and fatigue responses are similar between hypermobile and nonhypermobile dancers.

Acute Effect of Toe Cap Choice on Toe Deviation Angle and Perceived Pain in Female Professional Ballet Dancers

Several classical dance complex movements, such as pointe, require body weight to be supported properly to avoid risk of foot injury. Regarding the choice of toe cap for pointe shoes, it is unclear which type can better alleviate pain symptoms and toe deviation angle in dancers. The aim of the current crossover study was to investigate the acute effect of using different types of toe caps among well-trained professional dancers on pain perception and toe deviation angle. Ten young female professional dancers volunteered to participate in the study. Each participant was tested during two separate sessions with an interval of 72 h in between. Participants were tested in the two sessions with a standard commercial or a customized prototype toe cap, always with pointe shoes, and in randomized order. An anteroposterior X-ray examination was performed separately for each participant and a visual analogue scale for pain perception was administered following each situation (with a standard commercial or a customized prototype toe cap). Significant amelioration was obtained when a customized toe cap prototype was used both for toe deviation angle and for visual analogue scale. Use of a customized toe cap prototype compared to a standard one may acutely reduce both toe deviation angle and pain in elite female professional dancers.

Influence of dance training on challenging postural control task

BACKGROUND

Previous studies have shown that dance training affects postural control, particularly during challenging tasks. However, it is still unknown whether dance training also affects the ability to use vestibular, somatosensory, and visual cues, thus leading to postural control differences.

OBJECTIVE

The main goal of the present study was to evaluate the influence of dance training on sensory weighting during static postural control.

METHOD

The center of pressure of 24 participants was recorded (12 dancers and 12 control non-dancers) using a force platform as well as the modified Clinical Test of Sensory Organization in Balance (mCTISB).

RESULTS

The results suggest that dancers perform significantly better than controls in conditions where somatosensory cues are disturbed. Moreover, a significant negative correlation between vestibular frequency band and training intensity was observed, along with, a significant positive correlation between visual frequency band and training intensity.

SIGNIFICANCE

This research outlines dancers' increased ability to modulate sensory weighting differently than non-dancers during postural task where somatosensory cues are reduced.

The Physical Attributes Most Required in Professional Ballet: A Delphi Study

Background It is commonly accepted that dancers are undoubtedly athletes, with ballet perhaps the most demanding dance form. No previous study has sought to define the physical attributes most desired for classical ballet by professional companies and vocational schools. These are likely to include both aesthetic features and attributes that reduce the risk of injury as well as enhance performance. Method An initial survey question using the modified Delphi technique was sent using Opinio Survey Software to a selected international expert panel. This was drawn both from those involved in selection of elite professional ballet dancers, and the international medical professionals involved in the care of dancers. The first questionnaire was open-ended to scope for all the physical attributes most favoured by the professional experts. Results There were 148 responses from the panel of international experts. In total 34 physical attributes were suggested. The 2 most recommended physical criteria for selection into the profession were overall flexibility and overall strength. These results are discussed in the context of the published literature on the mechanics, anatomy and physiology of ballet. Conclusion Flexibility and strength are the 2 features most sought after in elite ballet dancers.

Postural control of Parkour athletes compared to recreationally active subjects under different sensory manipulations: A pilot study

In Parkour activity, the aim is to move from one place to another as quickly and efficiently as possible by running, climbing, swinging, vaulting, rolling, crawling and jumping on tiny obstacles … . Performing these actions places a great demand on the postural control system. The purpose of the present study was to investigate postural control of Parkour practitioners - called Traceurs - compared to recreationally active (RA) subjects in different postural conditions after manipulating the visual and/or proprioceptive sensory inputs. Ten Traceurs (mean experience 5.9 ± 0.9 years; >5 hours per week) and 10 RA subjects participated in this study. We measured the centre of pressure area (CoP_A) of the upright standing bipedal and unipedal postures in different postural conditions: on a firm and on a foam surfaces; on an oscillating surface in the sagittal plane and in the frontal plane in eyes open and eyes closed. To evaluate vision contribution, the Romberg index (RI) was calculated. Results showed that Traceurs presented a significant (P < .001) lower CoP_A values compared to RA subjects in eyes closed condition, suggesting that they were able to maintain a better balance control when vision is removed. Traceurs seems to be less dependent on visual cues (lower RI values) and proprioceptive inputs for maintaining balance than RA subjects. According to our study, Parkour training (experience for at least five years with a minimum of five hours per week) may improve postural abilities of young adult practitioners in specific postural conditions.

Effect of expertise in ballet dance on static and functional balance

RESEARCH QUESTION

The purpose of this study was to examine the postural sway characteristics of the ballet dance experts in quiet standing and at their limits of stability with an approach not used before in dancers.

METHODS

The study was conducted on thirteen female ballet dancers and thirteen non-training females. The data were collected with a use of a force plate. To gain a better insight into the postural control processes, we used the rambling-trembling and sample entropy analyses in the COP data processing.

RESULTS

The main findings of the study showed professional dancers to have higher values of postural sway characteristics in comparison to the non-trainees while performing simple motor tasks. Also, higher values of the trembling component in the group of dancers during quiet standing and the inclined positions were observed. This might be a sign of higher capacity of the postural system to deal with postural instability in dancers.

IMPORTANCE

Our results confirmed that the visual information is important in the process of postural control of dancers', which is proven by increased dislocations of the COP without visual feedback. The sample entropy results indicated more irregular characteristics of postural sway in ballet dancers representing more automated postural control. The data analysis methods showed high sensitivity to the subtle changes in postural control due to the dance training.

The effect of age on balancing behavior: complexity analysis of mediolateral force trajectories

OBJECTIVE

We quantified, via complexity analysis, the postural stability of healthy people from a wide age range.

APPROACH

Thirty-five healthy people aged 18-72 performed three tasks while balancing on one foot on a force plate: standard balancing task, mental task (balancing while answering basic arithmetic questions), and knot-tying task (balancing while tying two knots in a piece of ribbon). Mediolateral force trajectories were analyzed to determine control strategy via Hurst exponents, Lyapunov exponents, Kolmogorov complexity, root mean square, and phase-space plots.

MAIN RESULTS

We found increased pattern repetition in balancing with increased age, as evidenced by the emergence of a double attractor pattern in phase-space plots and the increase of Hurst exponents with age from approximately 0.3 to 0.8.

SIGNIFICANCE

As people age, they tend to develop strong feed-forward control strategies for balancing, and lose the complexity of micro movements intrinsic to young age. There is an open-loop control strategy for balancing that emerges in older adulthood, and there are attractors inherent to balancing which begin to develop in middle age.

Postural stability in a population of dancers, healthy non-dancers, and vestibular neuritis patients

INTRODUCTION

Several studies have indicated better balance control in dancers than in control participants, but some controversy remains. The aim of our study is to evaluate the postural stability in a cohort of dancers, non-dancers, compensated, and non-compensated unilateral vestibular neuritis (VN).

METHODS

This is a prospective study of control subjects, dancers, and VN patients between June 2009 and December 2015. Dancers from the Dance Conservatory of Madrid and VN patients were referred to our department for analysis. After the clinical history, neuro-otological examination, audiogram, and caloric tests, the diagnosis was done. Results from clinical examination were used for the categorization of compensation situation. A computerized dynamic posturography was performed to every subject.

RESULTS

Forty dancers and 38 women formed both 'dancer' and 'normal' cohorts. Forty-two compensated and 39 uncompensated patients formed both 'compensated' and 'uncompensated' cohorts. Dancers had significantly greater antero-posterior (AP) body sway than controls during condition 5 and 6 in the Sensory Organization Test (SOT) (p < .05). When we compared the uncompensated cohort with both control and dancers groups, we found significant greater body sway in every SOT studied condition (p < .05). While mean AP body say in SOT 5 and 6, showed greater values in compensated patients than the control group, the mean analysis did not show any statistical difference between the compensated and dancer groups, in such SOT conditions.

CONCLUSIONS

Dancers demonstrated greater sways than non-dancers when they relied their postural control on vestibular input alone. Compensated patients had a similar posturographic pattern that the dancers cohort, suggesting a similar shift from visual to somatosensory information.

Dynamic postural control and associated attentional demands in contemporary dancers versus non-dancers

Postural control is not a fully automatic process, but requires a certain level of attention, particularly as the difficulty of the postural task increases. This study aimed at testing whether experienced contemporary dancers, because of their specialized training involving the control of posture/balance, would present with a dual-task performance suggesting lesser attentional demands associated with dynamic postural control compared with non-dancers. Twenty dancers and 16 non-dancers performed a dynamic postural tracking task in both antero-posterior and side-to-side directions, while standing on a force platform. The postural task was performed, in turn, 1) as a stand-alone task, and concurrently with both 2) a simple reaction time task and 3) a choice reaction time task. Postural control performance was estimated through variables calculated from centre of pressure movements. Although no overall group difference was found in reaction time values, we found a better ability to control the side to side movements of the centre of pressure during the tracking task in dancers compared with non-dancers, which was dependent on the secondary task. This suggests that such increased ability is influenced by available attentional resources.

Ashtanga-Based Yoga Therapy Increases the Sensory Contribution to Postural Stability in Visually-Impaired Persons at Risk for Falls as Measured by the Wii Balance Board: A Pilot Randomized Controlled Trial

Objective

Persons with visual impairment (VI) are at greater risk for falls due to irreparable damage to visual sensory input contributing to balance. Targeted training may significantly improve postural stability by strengthening the remaining sensory systems. Here, we evaluate the Ashtanga-based Yoga Therapy (AYT) program as a multi-sensory behavioral intervention to develop postural stability in VI.

Design

A randomized, waitlist-controlled, single-blind clinical trial

Methods

The trial was conducted between October 2012 and December 2013. Twenty-one legally blind participants were randomized to an 8-week AYT program (n = 11, mean (SD) age = 55(17)) or waitlist control (n=10, mean (SD) age = 55(10)). AYT subjects convened for one group session at a local yoga studio with an instructor and two individual home-based practice sessions per week for a total of 8 weeks. Subjects completed outcome measures at baseline and post-8 weeks of AYT. The primary outcome, absolute Center of Pressure (COP), was derived from the Wii Balance Board (WBB), a standalone posturography device, in 4 sensory conditions: firm surface, eyes open (EO); firm surface, eyes closed (EC); foam surface, EO; and foam surface, EC. Stabilization Indices (SI) were computed from COP measures to determine the relative visual (SI_firm, SI_foam), somatosensory (SI_EO, SI_EC) and vestibular (SI_V, i.e., Foam_EC vs. Firm_EO) contributions to balance. This study was not powered to detect between group differences, so significance of pre-post changes was assessed by paired samples t-tests within each group.

Results

Groups were equivalent at baseline (all p > 0.05). In the AYT group, absolute COP significantly increased in the Foam_EO (t(8) = -3.66, p = 0.01) and Foam_EC (t(8) = -3.90, p = 0.01) conditions. Relative somatosensory SI_EO (t(8) = -2.42, p = 0.04) and SI_EC (t(8) = -3.96, p = 0.01), and vestibular SI_V (t(8) = -2.47, p = 0.04) contributions to balance increased significantly. As expected, no significant changes from EO to EC conditions were found indicating an absence of visual dependency in VI. No significant pre-post changes were observed in the control group (all p > 0.05).

Conclusions

These preliminary results establish the potential for AYT training to develop the remaining somatosensory and vestibular responses used to optimize postural stability in a VI population.

Trial Registration

www.ClinicalTrials.govNCT01366677

An Approach to Ballet Dance Training through MS Kinect and Visualization in a CAVE Virtual Reality Environment

This article proposes a novel framework for the real-time capture, assessment, and visualization of ballet dance movements as performed by a student in an instructional, virtual reality (VR) setting. The acquisition of human movement data is facilitated by skeletal joint tracking captured using the popular Microsoft (MS) Kinect camera system, while instruction and performance evaluation are provided in the form of 3D visualizations and feedback through a CAVE virtual environment, in which the student is fully immersed. The proposed framework is based on the unsupervised parsing of ballet dance movement into a structured posture space using the spherical self-organizing map (SSOM). A unique feature descriptor is proposed to more appropriately reflect the subtleties of ballet dance movements, which are represented as gesture trajectories through posture space on the SSOM. This recognition subsystem is used to identify the category of movement the student is attempting when prompted (by a virtual instructor) to perform a particular dance sequence. The dance sequence is then segmented and cross-referenced against a library of gestural components performed by the teacher. This facilitates alignment and score-based assessment of individual movements within the context of the dance sequence. An immersive interface enables the student to review his or her performance from a number of vantage points, each providing a unique perspective and spatial context suggestive of how the student might make improvements in training. An evaluation of the recognition and virtual feedback systems is presented.

Swimming and other sporting activities and the rate of falls in older men: longitudinal findings from the Concord Health and Ageing in Men Project

Balance training is the most efficacious exercise to prevent falls. This study examined the associations between common sporting activities and the incidence of falls, and whether lower risks can be attributed to the superior balance of sports participants. We studied a population-based cohort of 1,667 older Australian men (mean age = 76.8 years) in the Concord Health and Ageing in Men Project (CHAMP) between 2005 and 2011. Data on incident falls were captured by 12 triannual telephone call cycles per participant and were analyzed using negative binomial regression. The length of follow-up averaged 43.8 months (median, 48 months), during which time 2,662 falls were recorded. In unadjusted models, golfers (n = 160; incidence rate ratio (IRR) = 0.65, 95% confidence interval (CI): 0.47, 0.89) and swimmers (n = 88; IRR = 0.47, 95% CI: 0.30, 0.71) had significantly lower risks of falling. After adjustment for leisure-time physical activity, walking, lifestyle physical activity score (e.g., chores, gardening), and conventional risk factors for falling, swimming was the only activity that was associated with a protective effect (IRR = 0.67, 95% CI: 0.45, 1.00). Swimmers had significantly lower postural sway (β = -5.23 cm(2), P < 0.05) and shorter time to complete a narrow walk test than men who took part in only lifestyle physical activities. Balance indicators were strong predictors of the incidence of falls. The IRR for swimmers was 0.71 (95% CI: 0.48, 1.06) after adding balance measures to the adjusted model.

Comparison of static balance and the role of vision in elite athletes

When prescribing balance exercises to athletes in different sports, it may be important to recognize performance variations. Indeed, how athletes from different sports perform on balance tests is not well understood. The goal of the present study was to compare static balance and the role of vision among elite sprinters, jumpers and rugby players. The modified clinical test of sensory interaction on balance (mCTSIB) was used to assess the velocity of the center-of-pressure (CoP) on a force platform during a 30 s bipedal quiet standing posture in 4 conditions: firm surface with opened and closed eyes, foam surface with opened and closed eyes. Three-factor ANOVA indicated a significant main effect for groups (F=21.69, df=2, p<0.001, η² = 0.34). Significant main effect of vision (F=43.20, df=1, p<0.001, η² = 0.34) and surface (F=193.41, df=1, p<0.001, η² = 0.70) as well as an interaction between vision (eyes open, eyes closed) and surface (firm and foam) (F=21.79, df=1, p=0.001) were reported in all groups. The subsequent Bonferroni-Dunn post hoc test indicated that rugby players displayed better static balance than sprinters and jumpers (p=0.001). The comparison of sprinters and jumpers did not reveal significant differences (p>0.05). The nature of the sport practiced and the absence of visual control are linked to modify static balance in elite athletes. Coaches and strength and conditioning professionals are recommended to use a variety of exercises to improve balance, including both exercises with opened and closed eyes on progressively challenging surfaces in order to make decisions about tasks and sensory availability during assessment and training.

Taekwondo training improves balance in volunteers over 40

Balance deteriorates with age, and may eventually lead to falling accidents which may threaten independent living. As Taekwondo contains various highly dynamic movement patterns, Taekwondo practice may sustain or improve balance. Therefore, in 24 middle-aged healthy volunteers (40–71 year) we investigated effects of age-adapted Taekwondo training of 1 h a week during 1 year on various balance parameters, such as: motor orientation ability (primary outcome measure), postural and static balance test, single leg stance, one leg hop test, and a questionnaire. Motor orientation ability significantly increased in favor of the antero-posterior direction with a difference of 0.62° toward anterior compared to pre-training measurement, when participants corrected the tilted platform rather toward the posterior direction; female gender being an independent outcome predictor. On postural balance measurements sway path improved in all 19 participants, with a median of 9.3 mm/s (range 0.71–45.86), and sway area in 15 participants with 4.2 mm²/s (range 17.39–1.22). Static balance improved with an average of 5.34 s for the right leg, and with almost 4 s for the left. Median single leg stance duration increased in 17 participants with 5 s (range 1–16), and in 13 participants with 8 s (range 1–18). The average one leg hop test distance increased (not statistically significant) with 9.5 cm. The questionnaire reported a better “ability to maintain balance” in 16. In conclusion, our data suggest that age-adapted Taekwondo training improves various aspects of balance control in healthy people over the age of 40.

Comparison of postural stability between injured and uninjured ballet dancers

BACKGROUND

Ballet movements require a limited base of support; thus, ballet dancers require a high level of postural control. However, postural stability in ballet dancers is still unclear and needs to be understood.

PURPOSE

To evaluate ballet dancers' postural stability in performing single-leg standing, the en pointe task, and the first and fifth positions and to determine differences in task performance among healthy nondancers, healthy dancers, and dancers with ankle sprains.

STUDY DESIGN

Controlled laboratory study.

METHODS

Injured dancers, uninjured dancers, and nondancers were recruited for this study (N = 33 age-matched participants; n= 11 per group). The tasks tested were single-leg standing with eyes open and closed, first position, fifth position, and en pointe. Center of pressure parameters were calculated from the ground-reaction force collected with 1 force plate. Analysis of variance was used to assess the differences of center of pressure parameters among 3 groups in single-leg standing; independent t test was used to examine the differences of center of pressure parameters between injured and uninjured dancers.

RESULTS

During single-leg standing, injured dancers had significantly greater maximum displacement in the medial-lateral direction and total trajectory of center of pressure, compared with the uninjured dancers and nondancers. During the first and fifth positions, the injured dancers demonstrated significantly greater standard deviation of center of pressure position in the medial-lateral and anterior-posterior directions, compared with the uninjured dancers. During en pointe, the injured dancers had significantly greater maximum displacement in the medial-lateral direction and the anterior-posterior direction, compared with the uninjured dancers.

CONCLUSION

The injured and uninjured dancers demonstrated differences in postural stability in the medial-lateral direction during single-leg standing and the ballet postures. Although the injured dancers received ballet training, their postural stability may still be inferior to that of the nondancers.

CLINICAL RELEVANCE

This study is a first step in understanding that injured ballet dancers do not have the same postural stability as uninjured dancers and that it is even inferior to that of nondancers, which is important to understand for further study on rehabilitation. The future development of effective balance training programs for ballet dancers with ankle injuries should emphasize improvements in medial-lateral directional balance.

Effect of narrowing the base of support on the gait, gaze and quiet eye of elite ballet dancers and controls

We determined the gaze and stepping behaviours of elite ballet dancers and controls as they walked normally and along progressively narrower 3-m lines (l0.0, 2.5 cm). The ballet dancers delayed the first step and then stepped more quickly through the approach area and onto the lines, which they exited more slowly than the controls, which stepped immediately but then slowed their gait to navigate the line, which they exited faster. Contrary to predictions, the ballet group did not step more precisely, perhaps due to the unique anatomical requirements of ballet dance and/or due to releasing the degrees of freedom under their feet as they fixated ahead more than the controls. The ballet group used significantly fewer fixations of longer duration, and their final quiet eye (QE) duration prior to stepping on the line was significantly longer (2,353.39 ms) than the controls (1,327.64 ms). The control group favoured a proximal gaze strategy allocating 73.33% of their QE fixations to the line/off the line and 26.66% to the exit/visual straight ahead (VSA), while the ballet group favoured a 'look-ahead' strategy allocating 55.49% of their QE fixations to the exit/VSA and 44.51% on the line/off the line. The results are discussed in the light of the development of expertise and the enhanced role of fixations and visual attention when more tasks become more constrained.

Low-level Taekwondo practitioners have better somatosensory organisation in standing balance than sedentary people

Sports training, especially for those requiring fast and skilled movements have been reported to improve one's postural control, but the underlying sensory integration mechanism is unknown. The purpose is to explore the sensory organisation strategies for maintaining standing balance in Taekwondo practitioners, and to examine the quasi-static and dynamic balance performance in subjects with and without TKD training. Case-control study was used as a study design. Eleven subjects with low level of Taekwondo training for 1-3 years, and eleven sedentary healthy subjects were assessed with the sensory organisation tests (SOT) under six visual and somatosensory input conditions and their balance upon landing from self- or operator-triggered drop test with the eyes closed condition. The SOT measured the equilibrium scores, whereas the drop test assessed the time to stabilisation (TTS), normalised peak force and distance of antero-posterior and medial-lateral centre of pressure on landing. Results for the SOT test revealed that Taekwondo subjects performed better during stance with eyes closed on a fixed support than the untrained group (p = 0.011). For the drop tests, the untrained group was slower in postural correction as revealed by the longer TTS than the Taekwondo group after the operator-triggered drops (p = 0.018). All subjects had a larger normalised peak force in operator-triggered than self-triggered drops. In conclusion, we observed that people with low-level Taekwondo training have better balance performance than untrained subjects as shown in the SOT results and shorter TTS with the drop test. They may rely more on the somatosensory and vestibular inputs for maintaining balance. People with balance problems may benefit from Taekwondo training.

Sway regularity reflects attentional involvement in postural control: effects of expertise, vision and cognition

We examined the time varying (dynamic) characteristics of center-of-pressure (COP) fluctuations in a group of 14 preadolescent dancers and 16 age-matched non-dancers. The task involved maintaining balance for 20s with eyes open or eyes closed, and with or without performing an attention demanding cognitive task (word memorization). The main finding was that the time-dependent structure of the COP trajectories of dancers exhibited less regularity than that of non-dancers, as evidenced by a higher sample entropy (decreased statistical regularity). COP irregularity also increased during secondary task performance but decreased during standing with eyes closed. The combined findings indicate that the degree of attentional involvement in postural control - as reflected in the COP dynamics - varies along an automaticity continuum, and is affected by relatively stable subject characteristics (expertise) and more transient factors related to the attentional requirements of the task at hand.

The effect of a senior jazz dance class on static balance in healthy women over 50 years of age: a pilot study

The purpose of this pilot study is to assess the impact of a senior jazz dance class on static balance for healthy women over 50 years of age using the NeuroCom Smart Balance Master System (Balance Master). A total of 12 healthy women aged 54-88 years completed a 15-week jazz dance class which they attended 1 time per week for 90 min per class. Balance data were collected using the Sensory Organization Test (SOT) at baseline (pre), at 7 weeks (mid), and after 15 weeks (post). An equilibrium score measuring postural sway was calculated for each of six different conditions. The composite equilibrium score (all six conditions integrated to 1 score) was used as an overall measure of balance. Repeated measures analyses of variance (ANOVAs) were used to compare the means of each participant's SOT composite equilibrium score in addition to the equilibrium score for each individual condition (1-6) across the 3 time points (pre, mid, post). There was a statistically significant difference among the means, p < .0005. Pairwise (Bonferroni) post hoc analyses revealed the following statistically significant findings for SOT composite equilibrium scores for the pre (67.33 + 10.43), mid (75.25 + 6.97), and post (79.00 + 4.97) measurements: premid (p = .008); prepost (p < .0005); midpost (p = .033). In addition, correlational statistics were used to determine any relationship between SOT scores and age. Results indicated that administration of a 15-week jazz dance class 1 time per week was beneficial in improving static balance as measured by the Balance Master SOT.

Effects of dynamic head tilts on sensory organization test performance: a comparison between college-age athletes and nonathletes

STUDY DESIGN

Controlled laboratory study.

OBJECTIVE

To compare postural performance measures of athletes with those of nonathletes when completing the standard Sensory Organization Test (SOT) and a modified SOT that included dynamic head tilts (DHT-SOT).

BACKGROUND

Authors of recently published research have suggested that modifications to the SOT protocol (eg, introduction of pitch and roll head tilts) may enhance the test's sensitivity when assessing postural stability in individuals with higher balance capabilities or with well-compensated sensory deficits.

METHODS AND MEASURES

Nineteen athletes and 19 nonathletes (group) completed both the SOT and DHT-SOT (protocol). During the SOT, participants stood upright as steadily as possible for 20 seconds during each of 6 different sensory conditions. As a variation of the SOT, the DHT-SOT incorporated active pitch and roll head tilts into the SOT protocol. Four 2-way mixed-model analyses of variance (with protocol as the repeated factor) were performed to determine if the composite equilibrium score or the visual, vestibular, or somatosensory ratio scores differed between the 2 groups across the 2 testing protocols.

RESULTS

Significant group-by-protocol interaction effects were present for both the composite equilibrium score and visual ratio. Follow-up simple main-effects analyses indicated that these measures did not differ between groups for the SOT protocol but were significantly different on the DHT-SOT.

CONCLUSIONS

The addition of dynamic head tilts to the SOT protocol resulted in subtle differences in balance function between athletes and nonathletes. Athletes demonstrated an increased ability to adapt to sensory disruptions during the DHT-SOT. Therapists should consider including active pitch and roll head tilts to the SOT when evaluating individuals with higher balance function or to detect subtle deficits in balance function.

LEVEL OF EVIDENCE

Diagnosis, level 3b.

Are there specific conditions for which expertise in gymnastics could have an effect on postural control and performance?

The first aim of this study was to analyse the effect of elite training, linked to expertise, in gymnastics on postural performance and control. For this purpose, body sway of expert gymnasts was compared to other sportsmen, non-experts and non-gymnasts, in two different postures: bipedal (easy and unspecific to gymnasts) and unipedal (difficult and fairly specific). The second aim was to compare the groups in the same tasks but in a visual condition for which they were not trained, i.e. with eyes closed. Postural performance was assessed by centre of gravity motion, which was computed from centre of pressure motion, estimating postural control. A significant difference between the two groups was observed for postural performance in the unipedal posture and with eyes open only. Regardless of their posture, the groups were similarly affected by removal of vision. Expertise in gymnastics seemed to improve postural performances only in situations for which their practise is related to, i.e. unipedal with eyes open. These reveal the importance of choosing a relevant postural configuration and visual condition according to the people's training or by extension experience.

Posturographic testing and motor learning predictability in gymnasts

PURPOSE

One aim of this study was to find if there was a difference between balance and stability between elite level gymnasts and non-gymnasts. Another aim was to find if there was a relationship between dynamic posturographic scores associated with sway fatigue or adaptability and the ability to learn new gymnastic routines. The ultimate aim of the study was to improve gymnastic performance while reducing the probability of injury.

METHODS

Computer dynamic posturography (CDP) provided stability scores, fatigability ratios and adaptation ratios in elite level gymnasts and non-gymnasts controls. Relationships between the postural integrity of gymnasts and non-gymnasts were calculated. The gymnasts were trained in a novel gymnastic routine and performance outcomes were compared to the CDP outcomes.

RESULTS

Tests of postural stability have shown that gymnasts have greater postural stability than non-gymnasts. Gymnasts whose adaptability scores were higher were able to learn and perform new motor routines better than those with lower adaptability scores or high fatigability ratios.

CONCLUSIONS

While gymnasts have greater postural integrity than do non-gymnasts, CDP can identify individuals whose ability to perform new motor activities might be impaired. Methodology to improve functional stability not associated with the motor task may contribute to increased sports performance and decreased probability of injury.

Dynamic balance sensory motor control and symmetrical or asymmetrical equilibrium training

OBJECTIVE

Determine whether symmetrical or asymmetrical equilibrium training can enhance the proprioceptive input of the left versus right supporting leg (SL) motor control.

METHODS

Proprioceptive input was tested using a seesaw platform through a cross-sectional study. The total spectral energy was recorded and divided into 0-2 and 2-20Hz frequency bands. Experts in asymmetrical tasks (soccer players) were compared to experts in symmetrical tasks (dancers, acrobats) and untrained subjects according to pitch versus roll imbalance direction on each SL.

RESULTS

Regarding the low frequency band, spectral energy values were lower for experts than for untrained subjects in the roll direction only, whatever the SL (p<0.05). Regarding the high frequency band, spectral energy values were lower for the left SL compared to the right one for soccer players only (p<0.05). Furthermore, soccer players also exhibited lower values than other subjects on the left SL.

CONCLUSIONS

Asymmetrical equilibrium training minimizes the proprioceptive input, emphasizing the role of the biomechanical component in postural regulation.

SIGNIFICANCE

Testing athletes on a spontaneous unstable platform is a way to accurately discriminate each SL performance for one type of sport training. In sport medicine rehabilitation, injured SL could be detected with this protocol comparing it with healthy SL.