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Active video games (AVG) have been used as training tools and are known to ameliorate balance performance in children with Developmental Coordination Disorder (DCD). Our aim was to evaluate balance using clinical tests and by measuring body sway using a force plate with a mixed design of vision (eyes open/eyes closed), surface (rigid/soft), and support (stance/semitandem) before, and after, training and 4 months later (follow-up). Thirty-six DCD children and 40 typically developing children participated in the study, of which 50 children (26 DCD; 24 typically developing) were retested after 4 months. Balance improved on the clinical measures after the training, which was independent of type of AVG (Wii-Fit and Xbox Kinect) used, and this effect was still present after 4 months. The AVG training did not influence general sway behavior, but only sway in the eyes-open condition, corresponding with task demands of the training and indicating a training-specific effect. Overall, DCD children and typically developing children responded comparably to the AVG training, thereby maintaining the gap in performance between the two groups. The changes in postural sway are interpreted as a sign of more confidence and less freezing of the joints, enabling greater flexibility of movements and balance strategies as supported by the improved performance on balance tests in the DCD children. This is the first study that showed long-term effects of AVG training on balance performance. However, these follow-up results should be interpreted with caution given that 35% of the children were lost in follow-up.

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INTRODUCTION: Low back pain is highly prevalent worldwide and in Brazil. Postural control is a functional limitation in patients with low back pain. Postural control can be investigated through the centre of pressure (CoP) displacement, using a baropodometry. However, there is a lack of validation data about posturography variables obtained from the baropodometer. This study aimed to investigate the concurrent validity of the displacement of CoP measured through baropodometer T-Plate® in patients with chronic non-specific low back pain during three tasks. METHOD: A validation study was conducted in 37 participants with chronic non-specific low back pain during three different tasks, including bipedal support, bipedal support holding bags, and bipedal squatting holding bags. The tasks were performed on a baropodometer (index method) placed on a force plate (criterion measure). Measurements included velocity, amplitude of displacement, and sway area. RESULTS: Weak to strong correlations were found in the three tasks between the baropodometer and the force plate for most variables. The Bland-Altman analyses revealed no substantive differences between the two methods for the standard deviation of amplitude mediolateral and sway area for the three tasks. There was a systematic bias for the mean velocity and the standard deviation of amplitude anteroposterior displacement in the three tasks. CONCLUSION: The baropodometer could be used to measure the displacement of the CoP in patients with chronic non-specific low back pain. Sway area showed an appropriate validity to measure postural stability of the participants using the baropodometer.

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The popularity of running has increased over the past few years. However, just a few studies in running have focused on the friction between surface and shoe/foot. Changes in friction can affect aspects of human motion, such as safety, motion pattern and efficiency among others. The aim was to investigate the effects of cadence (walk, self-selected running and imposed-running), stance sub-phases (absorption and propulsion) and footwear (barefoot and shod) on the required coefficient of friction (RCOF) of regular runners. Twenty healthy runners (12 males, 8 females, 29.4 ± 4.9 years, 70.4 ± 9.6 kg) participated in this study. Two force plates were used to measure the ground reaction forces (GRF) in order to calculate the RCOF for each condition and the stance phase was divided in sub-phases. In walk, the RCOF was smaller in the absorption than in propulsion phase (p < 0.001). Results evidenced effects of the cadence (p < 0.001), stance sub-phases (p < 0.001) and footwear (p < 0.001) on the RCOF. There was interaction effect in cadence with stance sub-phases (p < 0.001) and footwear with stance sub-phases (p < 0.001). Our results show RCOF is influenced by cadence and footwear condition in the absorption phase.

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Abstract Aim: Lower-body non-contact injuries in team sport athletes (TSAs) are associated when absorbing force, during cutting and landing movements due to a lack of eccentric strength and decreased neuromuscular control leading to excessively higher joint forces. Thus, this project aimed to identify if TSAs had different acceleration and deceleration force profiles compared to a control group (non-TSA) when performing drop jumps (DJs). Methods: University TSAs (n = 15) and non-TSAs (n = 10) performed a series of DJs from a 39 cm box onto a force-plate. All data were normalized to the individual's body mass. Between-group differences in ground reaction force (GRF), rate of force development (RFD), and propulsive and breaking impulses were compared via t-tests and standardized differences. Results: TSAs had significantly, and meaningfully greater RFD than the non-TSAs (p < 0.01, Hedges' g (ES) = 1.24, 53%). While not statistically significant, the non-TSA group produced practically larger mean GRFs than TSAs (p = .09, ES = 0.72, 12.1%). No significant or meaningful between-group differences were detected for propulsive impulse (p = 0.08, ES = 0.41, 9.1%), braking impulse (p = 0.85, ES = 0.25, 4.6%), or impulse ratio (p = 0.35, ES = 0.21, 6.7%). Conclusions: This study shows the presence of significant RFD differences during the DJ in TSAs compared to non-TSAs. Furthermore, this investigation also showed there was no difference between TSA and students in GRF and impulse metrics. Implications from these findings suggest that TSAs can produce force rapidly, but deceleration metrics were not different from untrained students.

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BACKGROUND: To better understand gait initiation in individuals with stroke and suggest possible training strategies, we compared the gait initiation of individuals with stroke and age-matched controls, and we examined the influence of different amounts of body weight support (BWS) during the execution of gait initiation in individuals with stroke. MATERIALS AND METHODS: Twelve individuals with stroke and 12 age-matched controls initiated gait after a verbal command at a self-selected and comfortable speed, and individuals with stroke also initiated gait wearing a harness with 0%, 15%, and 30% of BWS. Length and velocity of the first step, distance between heels, and weight bearing in both lower limbs in the initial position were calculated. We also assessed the displacement and average velocity of the center of pressure (CoP) in the medial-lateral (ML) and anterior-posterior (AP) directions in 3 distinct sections during gait initiation, which correspond to the CoP position toward the swing limb, stance limb and progression line, respectively. RESULTS: Individuals with stroke presented shorter and slower step, shorter and slower CoP-ML and CoP-AP toward swing limb and Cop-ML towards stance limb, and longer and faster CoP-AP toward stance limb compared to their peers. The BWS lead individuals with stroke to decrease step length and to increase CoP-ML displacement and average velocity toward stance limb. CONCLUSION: Individuals with stroke present impairments in executing gait initiation mainly during the preparation period and the employment of an overground BWS system promotes a better performance. These results suggest that BWS is a functional strategy that enables individuals with stroke to modulate gait initiation and it could be adopted for gait intervention.

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O objetivo desta revisão foi verificar de que forma estão sendo realizadas as pesquisas que investigam o equilíbrio de idosos, utilizando-se a plataforma de força. Foi realizada busca por artigos indexados nas bases de dados SCIELO, MEDLINE e BVS, no período de 2011 a 2016. Foram selecionados 34 estudos para análise; destes, 27 estudos avaliaram a posição bipodal (olhos abertos e fechados); 25 estudos utilizaram o tempo de 0-30 segundos; e o tratamento, quando realizado, foi de treinamento de força e de equilíbrio.

The aim of this study was to identify in which way the researches that investigate the balance of the elderly using the force platform are being carried out. We searched for articles indexed in the SCIELO, MEDLINE and VHL databases from 2011 to 2016. We selected 34 studies for analysis, of which 27 studies evaluated the bipodal position (open and closed eyes), 25 studies used time of 0-30 seconds and the treatment, when performed, was of strength and balance training.

El objetivo de esta revisión fue verificar de qué forma se están realizando las investigaciones que investigan el equilibrio de ancianos, utilizando la plataforma de fuerza. Se realizó búsqueda por artículos indexados en las bases de datos SCielo, MEDLINE y BVS, en el período de 2011 a 2016. Se seleccionaron 34 estudios para análisis; de estos, 27 estudios evaluaron la posición bipodal (ojos abiertos y cerrados), 25 estudios utilizaron el tiempo de 0 a 30 segundos, y el tratamiento, cuando fue realizado, fue de entrenamiento de fuerza y de equilibrio.

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OBJECTIVE: To establish the convergent validity or relationship of the Balance Master® as balance assessment device by comparing its performance results with those obtained from the AccuSway Plus® force plate. METHOD: Cross-sectional observational study, without intervention, of 126 postmenopausal women (60.3 ± 3.2 years; body mass index = 27.6 ± 4.7 kg/m2). Two devices were used for the independent assessments of static balance: (a) Static postural balance assessment (posturography) was performed on a force platform (AccuSway Plus); (b) static evaluation was performed on the Balance Master®System. The variables studied in the two devices, were: (i) the Mean Velocity of the Center of Pressure Displacement in all directions (Vavg or Mean Firm), (ii) the Anteroposterior (Mean-Y) and (iii) the Mediolateral (Mean-X) Centers of Pressure Displacement. The Spearman correlation coefficient was calculated to measure the correlation of the variables of balance obtained with the two different devices. RESULTS: Significant correlations were obtained when the relationships between both variables were described by fitting multiple linear regression models. There was an association between the mean velocity of center of pressure displacement in both devices, with eyes open (r = 0.21) and eyes closed (r = 0.47). In the eyes open condition, Vavg increased, on average, 0.26 units, while Mean Firm increased 1.0 unit; in the Mean-Firm; in eyes closed condition, Vavg increased, on average, 1.27 units, while Mean-Firm increased by 1,0 unit. CONCLUSION: The devices investigated presented a significant correlation for the mean velocity calculated from the total displacement of the center of pressure in all directions.

OBJETIVO: Estabelecer a validade convergente ou relação do Balance Master® como dispositivo de avaliação do equilíbrio, comparando seus resultados de desempenho com os obtidos a partir da plataforma de força AccuSway Plus®. MÉTODO: Trata-se de um estudo observacional transversal, sem intervenção, de 126 mulheres na pós-menopausa (60,3 ± 3,2 anos; índice de massa corporal = 27,6 ± 4,7 kg/m2). A avaliação de equilíbrio postural estático (posturografia) para todos os voluntários foi realizada inicialmente em uma plataforma de força (AccuSway Plus); uma segunda avaliação estática foi realizada em um dispositivo de equilíbrio Balance Master® Sistem. As variáveis estudadas nos dois dispositivos, foram: velocidade média do deslocamento total do centro de pressão em todas as direções (Vavg e Média-Form); ântero-posterior (YSD and Mean-Y) e médio-lateral (XSD and X-Mean) do centro de pressão de deslocamento. O coeficiente de correlação de Spearman foram calculados para medir a correlação entre as variáveis de equilíbrio obtidas nos dois dispositivos diferentes. RESULTADOS: Foi encontrada uma correlação significativa entre as duas variáveis, e foi ajustado por um modelo de regressão linear. Houve uma associação entre a velocidade média de deslocamento do centro de pressão em ambos os dispositivos em ambas as condições, os olhos abertos (r = 0,21) e fechada (r = 0,47). Na condição de olhos abertos, os Vavg aumenta, em média, 0,26 unidades, com um aumento de uma unidade no Mean-Form; na condição de olhos fechados, Vavg aumenta, em média, 1,27 unidades, com um aumento de uma unidade no Mean-Form. CONCLUSÃO: Os dispositivos investigados apresentaram uma correlação significativa para a velocidade média calculada a partir do deslocamento total do centro de pressão em todas as direções.

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La estabilometría es el estudio del equilibrio que permite analizar el control postural y su relacion con la estabilidad en bípedo. Herramientas de alta tecnología se utilizan para medir la estabilidad en bípedo de forma cuantitativa con base en la posición del centro de gravedad de la persona determinado por la distribución de presiones plantares. Este artículo revisa el conocimiento científico sobre los conceptos en el trastorno de la estabilometría y la variedad de uso de estas herramientas en diferentes poblaciones y diagnósticos con base en artículos científicos encontrados en los últimos diez años en revistas indexadas. Se recomienda expandir el uso de las plataformas de fuerza que existen en Colombia a la estabilometría.

Stabilometry is the study of balance which permits the analysis of postural control as it relates to stability in standing. High tech tools are used to measure standing stability cuantitatively based on the position of the center of gravity of the person determined by his/ her distrubution of plantar pressures. This article reviews scientific knowlege regarding the concepts surrounding stabilomitry and the wide variety of uses of these tools in different populations and diagnoses based on scientific articles found in the last ten years in indexed journals. Expanding the use of the force plates that exist in Colombia to include stabilometry is recommended.

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CONTEXTUALIZAÇÃO: A manutenção do equilíbrio e da orientação corporal em humanos é garantida pelo adequado funcionamento do sistema de controle postural. A investigação desse controle tem despertado interesse em profissionais de diversas áreas, tais como, Fisioterapia, Educação Física, Engenharia, Física, Medicina, Psicologia, entre outras. OBJETIVOS: Revisar os métodos de análise experimental de dados utilizados para investigação do controle postural em seres humanos e demonstrar o cálculo e rotinas de programação das principais medidas utilizadas na avaliação desse controle. CONCLUSÃO: Os procedimentos experimentais e as medidas utilizadas na avaliação do controle postural apresentados nesta revisão poderão auxiliar na padronização da investigação do controle postural.

BACKGROUND: The maintenance of balance and body orientation in humans is guaranteed by the adequate functioning of the postural control system. The investigation of this control has awakened the interest of professionals from several fields such as Physical Therapy, Physical Education, Engineering, Physics, Medicine, Psychology, and others. OBJECTIVES: The purposes of this study are to revise the methods of data analysis used to investigate the postural control in human beings and to demonstrate the computational algorithms of the main measures used in the postural control evaluation. CONCLUSION: The experimental procedures and measures used in postural control evaluation presented in this review can help in the standardization of postural control investigation.

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