Analysis of different vibration patterns to guide blind people

[EN] The literature indicates the best vibration positions and frequencies on the human body where tactile information is transmitted. However, there is a lack of knowledge about how to combine tactile stimuli for navigation. The aim of this study is to compare different vibration patterns outputted to blind people and to determine the most intuitive vibration patterns to indicate direction for navigation purposes through a tactile belt. The vibration patterns that stimulate the front side of the waist are preferred for indicating direction. Vibration patterns applied on the back side of the waist could be suitable for sending messages such as stop.This research is supported by Seventh European Framework Programme (FP7/2007-2013) under grant agreement 605821 (BLINDTRACK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Durá-Gil, JV.; Bazuelo-Ruiz, B.; Moro Pérez, D.; Molla Domenech, F. (2017). Analysis of different vibration patterns to guide blind people. PeerJ. 5:1-10. https://doi.org/10.7717/peerj.30821105Cholewiak, R. W. (1999). The Perception of Tactile Distance: Influences of Body Site, Space, and Time. Perception, 28(7), 851-875. doi:10.1068/p2873Cholewiak, R. W., Brill, J. C., & Schwab, A. (2004). Vibrotactile localization on the abdomen: Effects of place and space. Perception & Psychophysics, 66(6), 970-987. doi:10.3758/bf03194989Cholewiak, R. W., & Craig, J. C. (1984). Vibrotactile pattern recognition and discrimination at several body sites. Perception & Psychophysics, 35(6), 503-514. doi:10.3758/bf03205946Faugloire, E., & Lejeune, L. (2014). Evaluation of heading performance with vibrotactile guidance: The benefits of information–movement coupling compared with spatial language. Journal of Experimental Psychology: Applied, 20(4), 397-410. doi:10.1037/xap0000032Ghiani, G., Leporini, B., & Paternò, F. (2009). Vibrotactile feedback to aid blind users of mobile guides. Journal of Visual Languages & Computing, 20(5), 305-317. doi:10.1016/j.jvlc.2009.07.004Johnson, L. A., & Higgins, C. M. (2006). A Navigation Aid for the Blind Using Tactile-Visual Sensory Substitution. 2006 International Conference of the IEEE Engineering in Medicine and Biology Society. doi:10.1109/iembs.2006.259473Kärcher, S. M., Fenzlaff, S., Hartmann, D., Nagel, S. K., & König, P. (2012). Sensory Augmentation for the Blind. Frontiers in Human Neuroscience, 6. doi:10.3389/fnhum.2012.00037Marston, J. R., Loomis, J. M., Klatzky, R. L., Golledge, R. G., & Smith, E. L. (2006). Evaluation of spatial displays for navigation without sight. ACM Transactions on Applied Perception, 3(2), 110-124. doi:10.1145/1141897.1141900Ranjbar, P., & Stenström, I. (2013). Monitor, a Vibrotactile Aid for Environmental Perception: A Field Evaluation by Four People with Severe Hearing and Vision Impairment. The Scientific World Journal, 2013, 1-11. doi:10.1155/2013/206734Saaty, T. L. (1990). How to make a decision: The analytic hierarchy process. European Journal of Operational Research, 48(1), 9-26. doi:10.1016/0377-2217(90)90057-iSrikulwong, M., & O’Neill, E. (2010). A Comparison of Two Wearable Tactile Interfaces with a Complementary Display in Two Orientations. Lecture Notes in Computer Science, 139-148. doi:10.1007/978-3-642-15841-4_15Van Erp, J. B. F. (2008). Absolute localization of vibrotactile stimuli on the torso. Perception & Psychophysics, 70(6), 1016-1023. doi:10.3758/pp.70.6.101

Objectifying user attention and emotion evoked by relevant perceived product components

[EN] A company’s aim is to develop products that engage user attention and evoke positive emotions. Customers base their emotional evaluation on product components that are relevant for their perception. This paper presents findings of both identifying relevant product components and measuring emotions evoked by relevant perceived product components. To validate results, the comparison with self-reporting methods identifies similarities and differences between explicit expressed and implicit recorded customer requirements. On the one hand, eye tracking is applied to deduce the attention provoked by perceived product components. In order to link the product strategy with product components, the paper presents results considering the fact that the gaze track is affected by current thoughts. (Köhler et al., 2013, 2014a, b; Köhler and Schmitt, 2012) On the other hand, since self-reporting tools are only useful for obtaining information about the conscious part of customers’ emotions, there is a need for measurement methods that measure the changes in physiological signals (bio-signals). Arousal is similar to emotional intensity and is related to the galvanic skin response. Positive or negative emotions are defined by the valence that is measured by facial electromyography. Findings are presented that relate changes in bio-signals on the aesthetical design to the global product impression as well as to emotions and, subsequently, linking changes in physiological signals to the evaluation of semantic concepts and design parameters. The presented approach provides conclusions and valid information about products as well as product components that provoke certain emotions and about product components linked to a certain product concept, which could be part of a product strategy. Consequently, hard facts and special design rules for emotional product design can be deduced.The paper presents results from the cooperative research project CONEMO (Consumer Evaluation Measurement for Objectified Industrial Use – funded by the CORNET program) of the Laboratory for Machine Tools and Production Engineering (WZL), RWTH Aachen University, Germany, together with the Institute of Biomechanics of Valencia (IBV), Spain. The funding agencies are IMPIVA (operational program FEDER of the Comunidad Valenciana, Spain) and AiF (Germany). The CORNET promotion plan 47EN of the Research Community for Quality (FQS), August-Schanz-Str. 21A, 60433 Frankfurt/Main, was funded by the AiF within the program for sponsorship by Industrial Joint Research and Development (IGF) of the German Federal Ministry of Economic Affairs and Technologies based on an enactment of the German parliament. The authors would like to express their gratitude to all parties involved.Schmitt, R.; Köhler, M.; Durá-Gil, JV.; Diaz Pineda, JA. (2014). Objectifying user attention and emotion evoked by relevant perceived product components. Journal of Sensors and Sensor Systems. 3(2):315-324. doi:10.5194/jsss-3-315-2014S31532432Beaujean, P., Grob, R., Häfen, K., Köbler, E., Köhler, M., Quattelbaum, B., Schmitt, R., Seitz, R., Wagner, M., and Willach, A.: Emotionale Produktgestaltung – Wert der wahrgenommenen Qualität, in: Proceedings: Tagungsband zum AWK, edited by: Brecher, C., Klocke, F., Schmitt, R., and Schuh, G., Shaker, 2011.Berghaus, N.: Eye-Tracking im stationären Einzelhandel. Eine empirische Analyse der Wahrnehmung von Kunden am Point of Purchase, dissertation, University Duisburg-Essen, 2005.Cacioppo, J. T., Tassinary, L. G., and Fridlund, A. J.: The skeletomotor system, in: Principles of Psychophysiology: Physical Social, and Inferential elements, edited by: Caccioppo, J. T. Tassinary, L. G., Cambridge University Press, New York, 325–384, 1990.Cacioppo, J. T., Bernston, G. G, Larsen, J. T., Poehlmann, K. M., and Ito, T. A.: The psychophysiology of emotion, in: Handbook of Emotions, edited by: Lewis, M. and Haviland-Jones, J. M., The Guilford Press, New York, 173–191, 2004.Czerwinski, M., Horvitz, E., and Cutrell, E.: Subjective duration assessment: an implicit probe for software usability, in: Proceedings of the IHM-HCI 2001 Conference, Vol. 2, 167–170, 2001.Desmet, P.: Designing Emotions. Delft University of Technology, Department of Industrial Design, 2002.Duchowski, A. T.: Eye Tracking Methodology: Theory and Practice, Vol. 2., Springer, London, 2007.Falk, B., Schmitt, R., and Quattelbaum, B.: Product Quality from the Customers' Perspective – Systematic Elicitation and Deployment of Perceived Quality Information, in: Proceedings of the 6th CIRP-Sponsored International Conference on Digital Enterprise Technology, 216 pp., 2008.Hawlitzky, N.: Integriertes Qualitätscontrolling von Unternehmensprozessen, Gestaltung eines Quality-Gate-Konzeptes, dissertation, Technical University München, 2002.Heino, A., Van der Molen, H. H., and Wilde, G. J. S.: Risk-homeostatic processes in car following behaviour: electrodermal responses and verbal risk estimates as indicators of the perceived level of risk during a car-driving task, Report VK 90-22, Traffic Research Centre, University of Groningen, Haren, 1990.Hofer, N. and Mayerhofer, W.: Die Blickregistrierung in der Werbewirkungsforschung. Grundlagen und Ergebnisse, in: Der Markt, No. 49, 149 pp., 2010.Jiao, R., Zhang, Y., and Helander, M.: A Kansei mining system for affective design, Journal of Expert Systems with Applications, 30, 658–673, 2006.Köhler, M. and Schmitt, R.: Systematic Consumer Evaluation Measurement for Objectified Integration into the Product Development Process, in: Advances in Affective and Pleasurable Design, edited by: Ji, Y. G., CRC Press, 503–512, 2012.Köhler, M., Falk, B., and Schmitt, R.: Objectifying user attention caused by visually perceived product components, in: Proceedings of the 16th International Congress of Metrology, https://doi.org/10.1051/metrology/201314002, 2013.Köhler, M., Falk, B., and Schmitt, R.: Applying Eye-Tracking in Kansei Engineering Methodology for Design Evaluations in Product Development, KEER conference, Linköping, available at: http://dqi.id.tue.nl/keer2014/papers/KEER2014_125 (last access: 30 September 2014), 2014a.Köhler, M., Falk, B., and Schmitt, R.: Integrating User Attention for Design Evaluations in Customer-Orientated Product Development, in: Advances in Affective and Pleasurable Design, edited by: Ji, Y. G. and Choi, S., Proceedings of the 5th International Conference on Applied Human Factors and Ergonomics AHFE 2014, 19–23 July 2014, CRC Press, 428–439, 2014b.Kroeber-Riel, W. and Weinberg, P.: Konsumentenverhalten, Vol. 6, Vahlen, 1996.Lang, P. J., Greenwald, M. K., Bradley, M. M., and Hamm, A. O.: Looking at pictures: affective, facial, visceral, and behavioral reactions, Psychophysiology, 30, 261–273, 1993.Laparra-Hernández, J., Belda-Lois, J. M., Medina, E., Campos, N., and Poveda, R.: EMG and GSR signals for evaluating user's perception of different types of ceramic flooring, Journal of Industrial Ergonomics, 39, 326–332, 2009.Meffert, H.: Marketing. Grundlagen marktorientierter Unternehmensführung, Vol. 9, Gabler, 2000.Nagamachi, M.: Kansei/Affective Engineering, CRC Press, Florida, 2011.Nielsen, J. and Levy, J.: Measuring usability: preference vs. performance, Communications of the ACM 37, No. 4, 66–75, 1994.Regueiro, R. and León, O.: Estrés en desiciones cotidianas, Journal of Psicothema, 15, 533–538, 2003.Sattler, H.: Methoden zur Messung von Präferenzen für Innovationen, Zeitschrift für betriebswirtschaftliche Forschung (zfbf), Vol. 54/06, 154–176, 2006.Schütte, S.: Designing Feelings into Products. Integrating Kansei Engineering Methodology in Product Development, dissertation, University Linköping, 2002.Tversky, A. and Kahneman, D.: 1 Availability: a heuristic for judging frequency and probability, Cognitive Psychol., 5, 207–232, 1973.Yarbus, A. L.: Eye Movements and Vision, Plenum Press, 1967

Anthropometric Indicators as a Tool for Diagnosis of Obesity and Other Health Risk Factors: A Literature Review

[EN] Obesity is characterized by the accumulation of an excessive amount of fat mass (FM) in the adipose tissue, subcutaneous, or inside certain organs. The risk does not lie so much in the amount of fat accumulated as in its distribution. Abdominal obesity (central or visceral) is an important risk factor for cardiovascular diseases, diabetes, and cancer, having an important role in the so-called metabolic syndrome. Therefore, it is necessary to prevent, detect, and appropriately treat obesity. The diagnosis is based on anthropometric indices that have been associated with adiposity and its distribution. Indices themselves, or a combination of some of them, conform to a big picture with different values to establish risk. Anthropometric indices can be used for risk identification, intervention, or impact evaluation on nutritional status or health; therefore, they will be called anthropometric health indicators (AHIs). We have found 17 AHIs that can be obtained or estimated from 3D human shapes, being a noninvasive alternative compared to X-ray-based systems, and more accessible than high-cost equipment. A literature review has been conducted to analyze the following information for each indicator: definition; main calculation or obtaining methods used; health aspects associated with the indicator (among others, obesity, metabolic syndrome, or diabetes); criteria to classify the population by means of percentiles or cutoff points, and based on variables such as sex, age, ethnicity, or geographic area, and limitations.BODYPASS Project has received funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 779780. CIBER de Diabetes and Enfermedades Metabolicas Asociadas (CIBERDEM) is an Instituto de Salud Carlos III initiative. SM-H was an investigator in the Juan Rodes program (JR18/00051) financed by the Instituto de Salud Carlos III and the European Regional Development Fund (FEDER). Project (IMDEEA/2020/87) supported by Instituto Valenciano de Competitividad Empresarial (IVACE), call for proposals 2020 for Technology Centers of the Comunitat Valenciana, cofunded by ERDF Funds, EU Operational Program of the Comunitat Valenciana 2014-2020.Piqueras Fiszman, P.; Ballester Fernandez, A.; Durá-Gil, JV.; Martinez-Hervas, S.; Redón, J.; Real, JT. (2021). Anthropometric Indicators as a Tool for Diagnosis of Obesity and Other Health Risk Factors: A Literature Review. Frontiers in Psychology. 12:1-19. https://doi.org/10.3389/fpsyg.2021.6311791191

New technologies for customizing products for people with special necessities: project FASHION-ABLE

[EN] Mass-customization of wearable products are offered as a higher added value to the broad public and have to compete with ready-to-wear offer. However, people with specific requirements are not covered by the current mass-customised products. This is the case of the elderly, disabled, diabetic and obese population groups when wearing textiles, clothing, footwear and textile-based orthotic goods. Further, at present, available knowledge and flexibility of production equipment and machinery of small and medium-sized enterprises operating in these traditional industries (even those that already offer made-to-measure products to the mass public) is unable to respond to the individual needs among such heterogeneous groups. The FASHION-ABLE project has solved this problem with a comprehensive set of solutions.This work was supported by the European Commission [project number FP7.FoF.NMP.2011-4 Project 284 871] under FASHION-ABLE project (http://www.fashionable-project.eu/) Area: 'High tech solutions in production [...] for [...] healthy consumer goods'.Durá-Gil, JV.; Ballester Fernández, A.; Cavallaro, M.; Chiodi, A.; Ballarino, A.; Brondi, C.; Von Arnim, V.... (2016). New technologies for customizing products for people with special necessities: project FASHION-ABLE. International Journal of Computer Integrated Manufacturing. 30(7):724-737. https://doi.org/10.1080/0951192X.2016.1145803S72473730

SIMPLIT: Ensuring technology usability for the elderly

Purpose The aim of this work is to establish a reliable methodology to test if a product is simple, practical, and user-friendly for the elderly. We pursue a twofold objective: (i) to respond to companies that want to be responsive to this increasingly demanding group; (ii) to guarantee that the certified products are easy to use for the elderly. The methodol-ogy will consist of reliable protocols according to the quality required by the recognised certification bodies-in the Spanish case AENOR. Method The method we followed involves several steps: (i) assure the participation of elderly people with the collaboration one of the most important Spanish elderly associations: UDP 1.500.000 members; (ii) a field study (441 questionnaires) to obtain and classify the problems that elderly people experience with products; (iii) define testing proto-cols based on the fulfilling mandatory standards and usability tests. Usability tests are based on a hierarchical classifica-tion of tasks and a categorical classification of the problems. We obtained data on the effectiveness, efficiency and ease of learning, with which elderly people achieve specified goals in particular environments; (iv) checking the process with 4 practical cases that cover low-tech and hi-tech products: the wardrobe, an activity park, an oven, and a tablet computer; (v) submitting protocols satisfying the requirements of a quality certification body. Results & Discussion As result we have developed a methodology with four steps. (i) Verification of the regulation (standards). We check compliance with the legislation on safety and ergonomics of the product to guarantee that it fulfills the minimum conditions. (ii) Ease-of-use tests. We analyse the learning of tasks, ease-of-use and efficacy of implementation, performing a diagnosis of the product based also on the assessment of elderly users. (iii) Global product diagnosis. (iv) Quality verification. We make sure that the product diagnosis is performed systematically by audit of the certification body (AENOR). The assessment of effectiveness, efficiency and ease of learning, are tasks classified on 4 levels: (a) basic & high frequency, (b) basic & low frequency, (c) no basic & high frequency, (d) no basic & low frequency. The problems that appear during the tasks are classified in 18 categories (e.g. dexterity, reaching, equilibrium, etc.). This problem classification facilitates the search for solutions and helps designers to improve the design. This methodology has resulted in a new certificate: SIMPLIT. SIMPLIT is a quality label that guarantees that products have been developed with a design aimed at elderly people. This certificate is now being used and several products have obtained the quality label. Moreover, we use the methodol-ogy in projects to develop new products for the elderly.Durá-Gil, JV.; Laparra Hernandez, J.; Poveda Puente, R.; Marzo Rosello, R.; López Vicente, MA.; Bollain Pastor, C. (2012). SIMPLIT: Ensuring technology usability for the elderly. Gerontechnology: international journal on the fundamental aspects of technology to serve the ageing society. 11(2):163-163. doi:10.4017/gt.2012.11.02.279.0016316311

Influence of the length of hospitalisation in post-discharge outcomes in patients with acute heart failure: Results of the LOHRCA study

Objective: To investigate the relationship between length of hospitalisation (LOH) and post-discharge outcomes in acute heart failure (AHF) patients and to ascertain whether there are different patterns according to department of initial hospitalisation. Methods: Consecutive AHF patients hospitalised in 41 Spanish centres were grouped based on the LOH (15 days). Outcomes were defined as 90-day post-discharge all-cause mortality, AHF readmissions, and the combination of both. Hazard ratios (HRs), adjusted by chronic conditions and severity of decompensation, were calculated for groups with LOH >6 days vs. LOH <6 days (reference), and stratified by hospitalisation in cardiology, internal medicine, geriatrics, or short-stay units. Results: We included 8563 patients (mean age: 80 (SD = 10) years, 55.5% women), with a median LOH of 7 days (IQR 4–11): 2934 (34.3%) had a LOH 15 days. The 90-day post-discharge mortality was 11.4%, readmission 32.2%, and combined endpoint 37.4%. Mortality was increased by 36.5% (95%CI = 13.0–64.9) when LOH was 11–15 days, and by 72.0% (95%CI = 42.6–107.5) when >15 days. Conversely, no differences were found in readmission risk, and the combined endpoint only increased 21.6% (95%CI = 8.4–36.4) for LOH >15 days. Stratified analysis by hospitalisation departments rendered similar post-discharge outcomes, with all exhibiting increased mortality for LOH >15 days and no significant increments in readmission risk. Conclusions: Short hospitalisations are not associated with worse outcomes. While post-discharge readmissions are not affected by LOH, mortality risk increases as the LOH lengthens. These findings were similar across hospitalisation departments

Validación de las ecuaciones predictivas del consumo de oxígeno y nuevas fórmulas para el entrenamiento interválico

[EN] Objectives. Our aims were to determine whether there is any significant difference between the measured and estimated energy expenditure for the most commonly used prediction equations in the literature, and to develop a new specific prediction equation for aerobic interval training with a broader cross-section of the population in terms of age, fitness and body mass index (BMI). Methods. Twenty healthy participants were recruited for this study. Two groups of ten people were established depending on their BMI. The low BMI group ranged between 19 and 22, and the high BMI group between 26 and 29. The test protocol consisted of 12 individualized intensities, 6 walking and 6 running speeds on a treadmill, measuring both heart rate and energy expenditure. The rest time between intervals ranged between 1 and 2 minutes Main results. The measured oxygen consumption was found to be significantly different from those predicted by the walking and running equations selected from the literature. The Leger equation was the best of the tested equations to estimate oxygen consumption for walking and the ACSM formula was the best for running. However, neither was found to be very accurate. Conclusions. The prediction equations selected from the literature in this study were not accurate enough to estimate oxygen consumption during aerobic interval training. We propose four new formulas to improve the estimation of the metabolic cost in interval activities in a population with wider characteristics than those found in the literature.[ES] Objetivos. Nuestro objetivo era determinar si existe alguna diferencia significativa entre el gasto energético calculado y previsto en las ecuaciones predictivas de uso más frecuente en la literatura, así como desarrollar una nueva ecuación predictiva específica para el entrenamiento interválico aeróbico con una muestra más transversal de la población en términos de edad, forma física e índice de masa corporal (IMC). Métodos. Se reclutó a veinte participantes sanos para el estudio. Se establecieron dos grupos de personas, en función de su IMC. El grupo con un IMC bajo tenía un IMC de entre 19 y 22 y el grupo con un IMC alto, uno de entre 26 y 29. El protocolo de las pruebas consistía en realizar 12 rutinas de intensidades individualizadas, 6 velocidades andando y 6 corriendo en cinta, y medir tanto la frecuencia cardíaca como el gasto energético. El tiempo de reposo entre intervalos varió de 1 a 2 minutos. Resultados principales. Se detectó que el consumo de oxígeno medido era significativamente distinto del predicho por las ecuaciones relativas tanto al ejercicio de andar como de correr seleccionadas entre la literatura. De entre las comprobadas, la ecuación de Léger fue la que arrojó mejores resultados para calcular el consumo de oxígeno al andar y la fórmula ACSM demostró ser la mejor para correr. Sin embargo, se comprobó que ninguna de las dos ofrecía una alta precisión. Conclusiones. Las ecuaciones predictivas seleccionadas de la literatura para este estudio no demostraron ser lo bastante precisas para calcular el consumo de oxígeno durante el entrenamiento interválico aeróbico. En este trabajo se proponen cuatro fórmulas nuevas para mejorar el cálculo del gasto metabólico en actividades interválicas en una población con características más amplias que las encontradas en la literatura.Bazuelo-Ruiz, B.; De Rosario Martínez, H.; Durá-Gil, JV. (2021). Validation of Oxygen Consumption Prediction Equations and New Formulas for Interval Training. Apunts. Educación física y deportes (Online). (143):9-16. https://doi.org/10.5672/apunts.2014-0983.es.(2021/1).143.0291614

Estimation de la dépense énergétique chez l¿adulte par l¿accélérométrie et fréquence cardiaque

[Otros] Objectifs. - Une détermination précise de la dépense énergétique (EE) par accélérométrie est importante pour l¿efficacité des programmes d¿AP. L¿écart d¿amplitude moyen (MAD) est un bon paramètre pour distinguer l¿intensité de l¿activité physique. Ici, les objectifs de la présente étude étaient doubles: a) développer une nouvelle équation d¿estimation de l¿EE utilisant les données brutes de l¿accéléromètre et la fréquence cardiaque, et b) comparer la consommation d¿oxygène mesurée avec la nouvelle équation développée et les équations de prédiction les plus utilisées la littérature chez les adultes de poids normal et en surpoids. Matériel et méthodes. - Vingt adultes en bonne santé (10 hommes et 10 femmes) portaient un appareil portable sur la poitrine qui intègre des signaux d¿accélérométrie triaxiale et d¿ECG. Le protocole de test consistait en 12 intensités individualisées, 6 vitesses de marche et 6 vitesses de course également réparties. La corrélation entre la MAD et la consommation d¿oxygène mesurée a été étudiée. Ensuite, une nouvelle équation d¿estimation de la dépense énergétique a été développée et comparée à cinq formules de la littérature. Résultats. - Nos résultats ont noté que MAD avait une très forte corrélation (r = 0,937) avec la calorimétrie indirecte. La nouvelle équation développée avait l¿une des deux erreurs absolues moyennes les plus faibles pour la marche et la course. Par conséquent, notre équation semble convenir à la fois à la marche et à la course, aux personnes de poids normal et en surpoids. Cependant, les études futures devraient valider notre nouvelle équation d¿estimation de l¿EE avec un large éventail de conditions de population et de terrain.[EN] Objectives. - Accurate determination of energy expenditure (EE) through accelerometry is relevant in the effectiveness of the PA programs. The mean amplitude deviation (MAD) is a good parameter to distinguish the intensity of physical activity. Here, the aims of the present study were twofold: a) to develop a new EE estimation equation using raw accelerometer data and heart rate, and b) to compare the oxygen consumption measured with the new equation developed and the most commonly used prediction equations in the literature in normal weight and overweight adults. Equipment and methods. - Twenty healthy adults (10 males and 10 females) wore a wearable device on the chest that integrates triaxial accelerometry and ECG signals. The test protocol consisted in 12 individualized intensities, 6 walking and 6 running speeds equally distributed. The correlation between MAD and measured oxygen consumption was investigated. Then, a new energy expenditure estimation equation was developed and compared with five formulas from the literature. Results. - Our results noted that MAD had a very high correlation (r = 0.937) with indirect calorimetry. The new equation developed had one of the two lowest mean absolute errors for both walking and running. Therefore, our equation appears to be suitable for both walking and running, for normal weight and overweight people. However, future studies should validate our new EE estimation equation with a wide range of population and field-based conditions.This work was supported by the Seventh European Framework Programme (FP7.FoF.NMP.2013-5) under grantagreement 609078 (EASY-IMP). The funders had no role instudy design, data collection and analysis, decision to publish, or preparation of the manuscript.Bazuelo-Ruiz, B.; De Rosario Martínez, H.; Durá-Gil, JV. (2022). Estimation of energy expenditure in adults with accelerometry and heart rate. Science & Sports. 37(5-6):431-437. https://doi.org/10.1016/j.scispo.2021.08.007431437375-

A Functional PCA Model for the Study of Time Series of Pressure Maps

[EN] Principal component analysis and functional regression are combined in a model to analyze a time series of pressure maps. The model is tested measuring the pressures over a chair seat while a subject performs a combination of simple movements. A sampling rate of 3 Hz is adequate for applying the model in sitting postures. The model is able to detect patterns of movement over time, although more variables are necessary if the movements produce similar pressure distributions.The research described in this paper arises from a Spanish research project called INREDIS (INterfaces for RElations between Environment and people with DISabilities) [http:// www.inredis.es]. INREDIS is led by Technosite and funded by CDTI (Industrial Technology Development Centre), under the CENIT (National Strategic Technical Research Consortia) Programme, in the framework of the Spanish government’s INGENIO 2010 initiative. The opinions expressed in this paper are those of the authors and are not necessarily those of the INREDIS project partners or of the CDTI.Chicote Gónzalez, JC.; Durá-Gil, JV.; Belda Lois, JM.; Poveda Puente, R. (2013). A Functional PCA Model for the Study of Time Series of Pressure Maps. Journal of Applied Biomechanics. 29(2):135-140. doi:10.1123/jab.29.2.13513514029

Effect of fatigue and gender on kinematics and ground reaction forces variables in recreational runners

The presence of fatigue has been shown to modify running biomechanics. Overall in terms of gender, women are at lower risk than men for sustaining running-related injuries, although it depends on the factors taken into account. One possible reason for these differences in the injury rate and location might be the dissimilar running patterns between men and women. The purpose of this study was to determine the effect of fatigue and gender on the kinematic and ground reaction forces (GRF) parameters in recreational runners. Fifty-seven participants (28 males and 29 females) had kinematic and GRF variables measured while running at speed of 3.3 m s−1 before and after a fatigue test protocol. The fatigue protocol included (1) a running Course-Navette test, (2) running up and down a flight of stairs for 5 min, and (3) performance of alternating jumps on a step (five sets of 1 minute each with 30 resting seconds between the sets). Fatigue decreased dorsiflexion (14.24 ± 4.98° in pre-fatigue and 12.65 ± 6.21° in fatigue condition, p < 0.05) at foot strike phase in females, and plantar flexion (−19.23 ± 4.12° in pre-fatigue and −18.26 ± 5.31° in fatigue condition, p < 0.05) at toe-off phase in males. These changes led to a decreased loading rate (88.14 ± 25.82 BW/s in pre-fatigue and 83.97 ± 18.83 BW/s in fatigue condition, p < 0.05) and the impact peak in females (1.95 ± 0.31 BW in pre-fatigue and 1.90 ± 0.31 BW in fatigue condition, p < 0.05), and higher peak propulsive forces in males (−0.26 ± 0.04 BW in pre-fatigue and −0.27 ± 0.05 BW in fatigue condition, p < 0.05) in the fatigue condition. It seems that better responses to impact under a fatigue condition are observed among women. Further studies should confirm whether these changes represent a strategy to optimize shock attenuation, prevent running injuries and improve running economy