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Jones R, Ratnakumar N, Akbaş K, Zhou X. Delayed center of mass feedback in elderly humans leads to greater muscle co-contraction and altered balance strategy under perturbed balance: A predictive musculoskeletal simulation study. PLoS One 2024; 19:e0296548. [PMID: 38787871 PMCID: PMC11125460 DOI: 10.1371/journal.pone.0296548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Falls are one of the leading causes of non-disease death and injury in the elderly, often due to delayed sensory neural feedback essential for balance. This delay, challenging to measure or manipulate in human studies, necessitates exploration through neuromusculoskeletal modeling to reveal its intricate effects on balance. In this study, we developed a novel three-way muscle feedback control approach, including muscle length feedback, muscle force feedback, and enter of mass feedback, for balancing and investigated specifically the effects of center of mass feedback delay on elderly people's balance strategies. We conducted simulations of cyclic perturbed balance at different magnitudes ranging from 0 to 80 mm and with three center of mass feedback delays (100, 150 & 200 ms). The results reveal two key points: 1) Longer center of mass feedback delays resulted in increased muscle activations and co-contraction, 2) Prolonged center of mass feedback delays led to noticeable shifts in balance strategies during perturbed standing. Under low-amplitude perturbations, the ankle strategy was predominantly used, while higher amplitude disturbances saw more frequent employment of hip and knee strategies. Additionally, prolonged center of mass delays altered balance strategies across different phases of perturbation, with a noticeable increase in overall ankle strategy usage. These findings underline the adverse effects of prolonged feedback delays on an individual's stability, necessitating greater muscle co-contraction and balance strategy adjustment to maintain balance under perturbation. Our findings advocate for the development of training programs tailored to enhance balance reactions and mitigate muscle feedback delays within clinical or rehabilitation settings for fall prevention in elderly people.
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Affiliation(s)
- Rachel Jones
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
| | - Neethan Ratnakumar
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
| | - Kübra Akbaş
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
| | - Xianlian Zhou
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
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Jouira G, Alexe CI, Zinelabidine K, Rebai H, Mocanu GD, Cojocaru AM, Dragomir L, Čaušević D, Sahli S. The Impact of Aerobic Dance Intervention on Postural Balance in Children: A Randomized Controlled Trial. CHILDREN (BASEL, SWITZERLAND) 2024; 11:573. [PMID: 38790568 PMCID: PMC11120053 DOI: 10.3390/children11050573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/25/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024]
Abstract
This study aimed to investigate the impact of an 8-week aerobic dance intervention on postural balance in children. Forty-one children, aged 9 to 11, were randomly assigned to either an aerobic dance group (ADG) or a control group (CG) from a primary school. Postural balance was assessed using center of pressure (CoP) excursions before and after the 8-week intervention period. Evaluations were conducted on both firm and foam surfaces in bipedal and unipedal stances under open-eyes (OE) and closed-eyes (CE) conditions, as well as on both medial-lateral (ML) and anterior-posterior (AP) surfaces in a bipedal stance under OE conditions. The ADG exhibited significantly decreased CoPVm values during firm bipedal CE, unipedal OE, foam bipedal OE and CE, and foam unipedal OE (p < 0.005). This study suggests that aerobic dance intervention improved postural balance in children, showcasing adaptability and improved stability under various conditions.
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Affiliation(s)
- Ghada Jouira
- Research Laboratory Education, Motricité, Sport et Santé (EM2S) LR19JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3029, Tunisia; (G.J.); (K.Z.); (S.S.)
| | - Cristina Ioana Alexe
- Department of Physical Education and Sports Performance, “Vasile Alecsandri” University of Bacău, 600115 Bacău, Romania
| | - Khawla Zinelabidine
- Research Laboratory Education, Motricité, Sport et Santé (EM2S) LR19JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3029, Tunisia; (G.J.); (K.Z.); (S.S.)
| | - Haithem Rebai
- Tunisian Research Laboratory ‘Sports Performance Optimization’ (LR09SEP01), National Center of Medicine and Science in Sports (CNMSS), Tunis 1002, Tunisia;
| | - George Danuț Mocanu
- Individual Sports and Physical Therapy Department, “Dunărea de Jos” University of Galati, 800008 Galați, Romania
| | - Adin Marian Cojocaru
- Faculty of Physical Education and Sport, Spiru Haret University, 041905 Bucharest, Romania;
| | - Luciana Dragomir
- Doctoral School of Accounting, Bucharest University of Economic Studies, 010374 Bucharest, Romania;
| | - Denis Čaušević
- Faculty of Sport and Physical Education, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Sonia Sahli
- Research Laboratory Education, Motricité, Sport et Santé (EM2S) LR19JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3029, Tunisia; (G.J.); (K.Z.); (S.S.)
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Duncan CA, Bishop N, Komisar V, MacKinnon SN, Byrne JM. The Effect of Wave Motion Intensities on Performance in a Simulated Search and Rescue Task and the Concurrent Demands of Maintaining Balance. HUMAN FACTORS 2022; 64:579-588. [PMID: 32930010 DOI: 10.1177/0018720820952907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
OBJECTIVE The purpose of this study was to examine how intensity of wave motions affects the performance of a simulated maritime search and rescue (SAR) task. BACKGROUND Maritime SAR is a critical maritime occupation; however, the effect of wave motion intensity on worker performance is unknown. METHODS Twenty-four participants (12 male, 12 female) performed a simulated search and rescue task on a six-degree-of-freedom motion platform in two conditions that differed in motion intensity (low and high). Task performance, electromyography (EMG), and number of compensatory steps taken by the individual were examined. RESULTS As magnitude of simulated motion increased, performance in the SAR task decreased, and was accompanied by increases in lower limb muscle activation and number of steps taken. CONCLUSIONS Performance of an SAR task and balance control may be impeded by high-magnitude vessel motions. APPLICATION This research has the potential to be used by maritime engineers, occupational health and safety professionals, and ergonomists to improve worker safety and performance for SAR operators.
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Affiliation(s)
| | - Nicole Bishop
- 7512 Memorial University of Newfoundland, St. John's, Canada
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Koh K, Park YS, Park DW, Shim JK. Dance training improves the CNS's ability to utilize the redundant degrees of freedom of the whole body. Sci Rep 2020; 10:22197. [PMID: 33335153 PMCID: PMC7747644 DOI: 10.1038/s41598-020-79081-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 11/30/2020] [Indexed: 11/09/2022] Open
Abstract
Professional dancers demonstrate an amazing ability to control their balance. However, little is known about how they coordinate their body segments for such superior control. In this study, we investigated how dancers coordinate body segments when a physical perturbation is given to their body. A custom-made machine was used to provide a short pulling impulse at the waist in the anterior direction to ten dancers and ten non-dancers. We used Uncontrolled Manifold analysis to quantify the variability in the task-relevant space and task-irrelevant space within the multi-dimensional space made up of individual segments’ centers of mass with a velocity adjustment. The dancers demonstrated greater utilization of redundant degrees of freedom (DoFs) supported by the greater task-irrelevant variability as compared to non-dancers. These findings suggest that long-term specialized dance training can improve the central nervous system’s ability to utilize the redundant DoFs in the whole-body system.
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Affiliation(s)
- Kyung Koh
- Department of Kinesiology, University of Maryland, College Park, MD, USA.,Department of Physical Therapy and Rehabilitation Science, University of Maryland, Baltimore, MD, USA
| | - Yang Sun Park
- Department of Sports Welfare, Korea National University of Transportation, Chungcheongbuk-do, South Korea.
| | - Da Won Park
- Department of Kinesiology, Seoul National University, Seoul, South Korea
| | - Jae Kun Shim
- Department of Kinesiology, University of Maryland, College Park, MD, USA. .,Department of Mechanical Engineering, Kyung Hee University, Yongin-Si, Gyeonggi-do, South Korea. .,Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD, USA. .,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
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Schinkel-Ivy A, Komisar V, Duncan CA. Quantifying Segmental Contributions to Center-of-Mass Motion During Dynamic Continuous Support Surface Perturbations Using Simplified Estimation Models. J Appl Biomech 2020; 36:198-208. [PMID: 32659743 DOI: 10.1123/jab.2019-0239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 03/26/2020] [Accepted: 04/07/2020] [Indexed: 11/18/2022]
Abstract
Investigating balance reactions following continuous, multidirectional, support surface perturbations is essential for improving our understanding of balance control in moving environments. Segmental motions are often incorporated into rapid balance reactions following external perturbations to balance, although the effects of these motions during complex, continuous perturbations have not been assessed. This study aimed to quantify the contributions of body segments (ie, trunk, head, upper extremity, and lower extremity) to the control of center-of-mass (COM) movement during continuous, multidirectional, support surface perturbations. Three-dimensional, whole-body kinematics were captured while 10 participants experienced 5 minutes of perturbations. Anteroposterior, mediolateral, and vertical COM position and velocity were calculated using a full-body model and 7 models with reduced numbers of segments, which were compared with the full-body model. With removal of body segments, errors relative to the full-body model increased, while relationship strength decreased. The inclusion of body segments appeared to affect COM measures, particularly COM velocity. Findings suggest that the body segments may provide a means of improving the control of COM motion, primarily its velocity, during continuous, multidirectional perturbations, and constitute a step toward improving our understanding of how the limbs contribute to balance control in moving environments.
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Affiliation(s)
| | | | - Carolyn A Duncan
- Michigan Technological University
- Toronto Rehabilitation Institute-University Health Network
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High contextual interference in perturbation-based balance training leads to persistent and generalizable stability gains of compensatory limb movements. Exp Brain Res 2020; 238:1249-1263. [PMID: 32303810 DOI: 10.1007/s00221-020-05806-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/07/2020] [Indexed: 01/03/2023]
Abstract
Reactive responses to balance perturbations have been shown to be improved by training. This investigation aimed to compare the effects of block and random training perturbation schedules on stability gains of compensatory arm and leg movements in response to unpredictable large-magnitude balance perturbations. Perturbations were produced by means of sudden displacements of the support base, associating mode (rotation, translation, combined), direction, and velocity of platform motion. Healthy young participants were assigned to one of three groups: random, block, and control. For the random group, perturbation sequence was unpredictable. For the block group, each balance perturbation was repeated over blocks of four trials. Controls were tested only, serving as reference of first trial responses in the post-test. Evaluation was made through a scale rating stability of compensatory arm and leg movements (CALM). We probed immediate and persistence gains (1-week retention), in addition to generalizability to perturbations of higher velocity and to dual-tasking (mental subtraction). In the post-test both the block and random groups achieved higher leg and global scores in comparison with controls in the most challenging perturbations. In retention and transfer tests, results for the global score indicated higher values for the random than for the block and control groups. These results support the conclusion that high but not low contextual interference in perturbation-based balance training leads to enduring and generalizable increased stability gains of compensatory limb movements in response to unpredictable balance perturbations.
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Komisar V, McIlroy WE, Duncan CA. Individual, task, and environmental influences on balance recovery: a narrative review of the literature and implications for preventing occupational falls. IISE Trans Occup Ergon Hum Factors 2019. [DOI: 10.1080/24725838.2019.1634160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Vicki Komisar
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | | | - Carolyn A. Duncan
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, MI
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Duncan CA, MacKinnon SN, Marais JF, Basset FA. Energy cost associated with moving platforms. PeerJ 2018; 6:e5439. [PMID: 30186679 PMCID: PMC6119458 DOI: 10.7717/peerj.5439] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 07/24/2018] [Indexed: 11/20/2022] Open
Abstract
Background Previous research suggests motion induced fatigue contributes to significant performance degradation and is likely related to a higher incidence of accidents and injuries. However, the exact effect of continuous multidirectional platform perturbations on energy cost (EC) with experienced personnel on boats and other seafaring vessels remains unknown. Objective The objective of this experiment was to measure the metabolic ECs associated with maintaining postural stability in a motion-rich environment. Methods Twenty volunteer participants, who were free of any musculoskeletal or balance disorders, performed three tasks while immersed in a moving environment that varied motion profiles similar to those experienced by workers on a mid-size commercial fishing vessel (static platform (baseline), low and high motions (HMs)). Cardiorespiratory parameters were collected using an indirect calorimetric system that continuously measured breath-by-breath samples. Heart rate was recoded using a wireless heart monitor. Results Results indicate a systematic increase in metabolic costs associated with increased platform motions. The increases were most pronounced during the standing and lifting activities and were 50% greater during the HM condition when compared to no motion. Increased heart rates were also observed. Discussion Platform motions have a significant impact on metabolic costs that are both task and magnitude of motion dependent. Practitioners must take into consideration the influence of motion-rich environments upon the systematic accumulation of operator fatigue.
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Affiliation(s)
- Carolyn A Duncan
- Department of Kinesiology and Integrative Physiology Michigan Tech Houghton, MI, USA
| | - Scott N MacKinnon
- Division of Maritime Studies, Chalmers University of Technology, Gothenburg, Sweden
| | - Jacques F Marais
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Fabien A Basset
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
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The effects of short-term and long-term experiences on co-contraction of lower extremity postural control muscles during continuous, multi-directional support-surface perturbations. J Electromyogr Kinesiol 2018; 39:42-48. [PMID: 29413452 DOI: 10.1016/j.jelekin.2018.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/15/2017] [Accepted: 01/21/2018] [Indexed: 01/09/2023] Open
Abstract
While reactive balance control in response to single perturbations in quiet standing is relatively well understood, some occupational environments (e.g. maritime environments) expose workers to continuous, multi-directional challenges to balance and postural control, which require workers to respond to the current perturbation, as well as anticipate coming perturbations. Investigation of muscle activation patterns during continuous, multi-directional perturbations, and the role of previous experience, is warranted to better understand postural control strategies in these types of environments. This study aimed to identify changes in co-contraction in the lower extremity postural control muscles during multi-directional support-surface perturbations as a result of short-term and long-term experience. Twenty-five participants (12 with minimal experience (novice), 13 with ≥6 months experience working in moving maritime environments (experienced)) were exposed to five 5-minute trials of continuous support-surface perturbations. Muscle activity was recorded from six muscles bilaterally. Co-contraction indices were calculated for selected muscle pairings and compared between groups and trials. Co-contraction decreased across trials, and was lower in the experienced group relative to the novice group. These findings provide insight into the influence of previous experience on muscle activation during reactive balance control, and suggest that increased co-contraction may be a potential mechanism of the increased risk of workplace fatigue, falls, and injury in novice maritime workers. The development and refinement of training programs targeting novice workers may be a potential avenue to reduce fall and injury risk in maritime environments.
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Petró B, Papachatzopoulou A, Kiss RM. Devices and tasks involved in the objective assessment of standing dynamic balancing - A systematic literature review. PLoS One 2017; 12:e0185188. [PMID: 28934308 PMCID: PMC5608356 DOI: 10.1371/journal.pone.0185188] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/07/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Static balancing assessment is often complemented with dynamic balancing tasks. Numerous dynamic balancing assessment methods have been developed in recent decades with their corresponding balancing devices and tasks. OBJECTIVE The aim of this systematic literature review is to identify and categorize existing objective methods of standing dynamic balancing ability assessment with an emphasis on the balancing devices and tasks being used. DATA SOURCES Three major scientific literature databases (Science Direct, Web of Science, PLoS ONE) and additional sources were used. STUDY SELECTION Studies had to use a dynamic balancing device and a task described in detail. Evaluation had to be based on objectively measureable parameters. Functional tests without instrumentation evaluated exclusively by a clinician were excluded. A total of 63 articles were included. DATA EXTRACTION The data extracted during full-text assessment were: author and date; the balancing device with the balancing task and the measured parameters; the health conditions, size, age and sex of participant groups; and follow-up measurements. DATA SYNTHESIS A variety of dynamic balancing assessment devices were identified and categorized as 1) Solid ground, 2) Balance board, 3) Rotating platform, 4) Horizontal translational platform, 5) Treadmill, 6) Computerized Dynamic Posturography, and 7) Other devices. The group discrimination ability of the methods was explored and the conclusions of the studies were briefly summarized. LIMITATIONS Due to the wide scope of this search, it provides an overview of balancing devices and do not represent the state-of-the-art of any single method. CONCLUSIONS The identified dynamic balancing assessment methods are offered as a catalogue of candidate methods to complement static assessments used in studies involving postural control.
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Affiliation(s)
- Bálint Petró
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary
| | | | - Rita M Kiss
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary
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Ma S, Chen X, Cao S, Yu Y, Zhang X. Investigation on Inter-Limb Coordination and Motion Stability, Intensity and Complexity of Trunk and Limbs during Hands-Knees Crawling in Human Adults. SENSORS 2017; 17:s17040692. [PMID: 28350324 PMCID: PMC5421652 DOI: 10.3390/s17040692] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/23/2017] [Accepted: 03/25/2017] [Indexed: 11/30/2022]
Abstract
This study aimed to investigate the inter-limb coordination pattern and the stability, intensity, and complexity of the trunk and limbs motions in human crawling under different speeds. Thirty healthy human adults finished hands-knees crawling trials on a treadmill at six different speeds (from 1 km/h to 2.5 km/h). A home-made multi-channel acquisition system consisting of five 3-axis accelerometers (ACC) and four force sensors was used for the data collection. Ipsilateral phase lag was used to represent inter-limb coordination pattern during crawling and power, harmonic ratio, and sample entropy of acceleration signals were adopted to depict the motion intensity, stability, and complexity of trunk and limbs respectively. Our results revealed some relationships between inter-limb coordination patterns and the stability and complexity of trunk movement. Trot-like crawling pattern was found to be the most stable and regular one at low speed in the view of trunk movement, and no-limb-pairing pattern showed the lowest stability and the greatest complexity at high speed. These relationships could be used to explain why subjects tended to avoid no-limb-pairing pattern when speed was over 2 km/h no matter which coordination type they used at low speeds. This also provided the evidence that the central nervous system (CNS) chose a stable inter-limb coordination pattern to keep the body safe and avoid tumbling. Although considerable progress has been made in the study of four-limb locomotion, much less is known about the reasons for the variety of inter-limb coordination. The research results of the exploration on the inter-limb coordination pattern choice during crawling from the standpoint of the motion stability, intensity, and complexity of trunk and limbs sheds light on the underlying motor control strategy of the human CNS and has important significance in the fields of clinical diagnosis, rehabilitation engineering, and kinematics research.
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Affiliation(s)
- Shenglan Ma
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China.
| | - Xiang Chen
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China.
| | - Shuai Cao
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China.
| | - Yi Yu
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China.
| | - Xu Zhang
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China.
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Should Ballet Dancers Vary Postures and Underfoot Surfaces When Practicing Postural Balance? Motor Control 2017; 22:45-66. [PMID: 28338396 DOI: 10.1123/mc.2016-0076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Postural balance (PB) is an important component skill for professional dancers. However, the effects of different types of postures and different underfoot surfaces on PB have not adequately been addressed. PURPOSE The main aim of this study was to investigate the effect of different conditions of footwear, surfaces, and standing positions on static and dynamic PB ability of young ballet dancers. METHODS A total of 36 male and female young professional ballet dancers (aged 14-19 years) completed static and dynamic balance testing, measured by head and lumbar accelerometers, while standing on one leg in the turnout position, under six different conditions: (1) "relaxed" posture; (2) "ballet" posture; (3) barefoot; (4) ballet shoes with textured insoles; (5) barefoot on a textured mat; and (6) barefoot on a spiky mat. RESULTS A condition effect was found for static and dynamic PB. Static PB was reduced when dancers stood in the ballet posture compared with standing in the relaxed posture and when standing on a textured mat and on a spiky mat (p < .05), and static PB in the relaxed posture was significantly better than PB in all the other five conditions tested. Dynamic PB was significantly better while standing in ballet shoes with textured insoles and when standing on a spiky mat compared with all other conditions (p < .05). CONCLUSIONS The practical implications derived from this study are that both male and female dancers should try to be relaxed in their postural muscles when practicing a ballet aligned position, including dance practice on different types of floors and on different types of textured/spiky materials may result in skill transfer to practice on normal floor surfaces, and both static and dynamic PB exercises should be assessed and generalized into practical dance routines.
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