Influence of energy cost and physical fitness on the preferred walking speed and gait variability in elderly women

Typically gait speed decreases and gait variability increases in elderly. The aim of this study was to define the influence of energy cost of walking on gait speed and of health-related physical fitness on gait variability. Thirty healthy young and older women were recruited in the study. Energy cost of walking (NetCW) was analyzed with indirect calorimetry while a kinematic analysis was performed with an optoelectronic system to calculate gait variability (GV) during treadmill walking at different speeds. Gait speed was defined as the preferred walking speed (PWS) of the subject and health related physical fitness (HRPF) comprised body fat, strength, flexibility, and cardiorespiratory fitness. In healthy elderly women, the coefficient of variation of step width was found to be a better indicator of GV than stride time, stride length and double support coefficients of variation. GV was not affected by age allowing a high PWS. Furthermore, significant associations, adjusted for age, body mass index and number of falls, were identified neither between NetCW and the PWS, nor between HRPF and GV; only a significant association was found between hand-grip strength and gait stability. Findings highlighted the importance to evaluate hand-grip strength as an indicator of gait efficiency

Kinematic evaluation of physical impairments of an elite Paralympic karateka

Karate is a Japanese martial art that counts millions of practitioners worldwide and that is spreading also in Paralympic competitions, requiring accurate categories definition for disabled athletes. The aim of the study is to present kinematic data of an elite Paralympic karateka, in comparison with able-bodied athletes. The authors also aim to promote a better classification within the discipline, based on objective biomechanical evaluations of physical impairments. A male black belt Paralympic karateka (age: 36 y; body weight: 75.5 kg; height: 173 cm) with lower limbs impairments was evaluated. The athlete had been performing high level karate for 20 years before the disability took place. After the post-operative rehabilitation, he attended 3/4 sessions of para- karate training per week. He performed a standardized sequence of movements, involving a sequence of offensive and defensive techniques, (kata) from traditional Shotokan karate. Joints and body Center of Mass (CoM) kinematics were collected with an optoelectronic motion capture system and compared with those obtained in two groups of able-bodied (elite and amateurs) athletes from a previous study1. Knee angular range of motion (RoM) and peak angular velocity were obtained. Coordinates of CoM were estimated, using the Segmental Centroid Method2, along with CoM average velocity and acceleration. To assess differences between Paralympic karateka and able-bodied groups, the one-sample t-test was performed. The sequence performed by the karateka lasted more than in both able-bodied groups. CoM average velocity and acceleration decreased in comparison with elite karateka. Knees range of movement and peak angular velocity were similar to amateur but lower than elite athletes. Results show that the physical impairments negatively affected the function of lower limbs in the Paralympic athlete. Fundamental skills in karate elite performance (dynamic balance control and joint RoM and angular velocity) were reduced

Influence of biological maturation on postural control in young soccer players

Biological maturation does not follow a linear development path; the process presents inter- individual differences concerning the timing of psychophysical development. The nonlinear nature of the biological maturation process often results in sudden and rapid modifications that can influence the sensorimotor functions, in particular when the peak height velocity (PHV) is approaching. Static standing balance and postural control are fundamental skills, both for daily living and sport performance, that can be strongly affected by PHV. We examined the influence of biological maturation on the performance of static standing balance, an index for sensorimotor control. Two-hundred and 38 young healthy soccer players (U9 to U17), playing in a sub-\ue9lite club (at least two training sessions and an official match per week), were evaluated. After anthropometric measurement, standing balance was assessed using a baropodometric platform (BTS P-Walk, Italy). Subjects stood barefooted on the platform and were recorded at 20 Hz during two 30-s tests, the first with eyes open and the second keeping eyes closed. Participants were split into six groups based on the Maturity Offset (MO), representing the estimated time to/from the PHV and calculated according to Mirwald et al1. The body center of pressure (CoP) sway area and velocity were calculated. Differences between MO groups were tested using a 2-factor (MO and condition) ANOVA with repeated measures on the condition factor (eyes open/closed). The sway area showed a decreasing trend as the MO increased, in particular in MO<-1.5 was higher than in MO>0.5 (p<0.001). Likewise, CoP velocity presented a similar pattern (p<0.001), with a marked decline in groups with MO>0.5. The results suggest that biological maturation is associated with changes in standing balance control. The reduction of CoP sway area and velocity as the MO increase represents the improved efficiency of the postural control system

The meaning of religious beliefs for a group of cancer patients during rehabilitation

Este estudo exploratório teve o objetivo de identificar como a religião influencia a sobrevivência de um grupo de pacientes oncológicos. Consistiu em estudo de caso etnográfico, com a participação de seis laringectomizados, de ambos os sexos, na faixa etária de 51 a 72 anos, operados de dois a cinco anos. Os dados foram coletados por entrevistas semi-estruturadas e analisados segundo os conceitos de cultura e religião. Sintetizou-se os resultados em três categorias descritivas: a representação moral do câncer, as crenças religiosas na trajetória do câncer e a negociação com a religião para a sobrevivência. O significado que emerge - "a expectativa por uma segunda chance" - enfatiza a importância da religião como parte das redes de apoio que se articulam com o enfrentamento do estigma do câncer, com a expectativa da cura e com as formas de organizar a vida cotidiana, na sobrevivência.La finalidad de este estudio exploratorio fue identificar cómo la religión influencia la supervivencia de un grupo de pacientes oncológicos. Consistió en un estudio de caso etnográfico con la participación de seis laringectomizados, de ambos sexos, con edad de 51 a 72 años, que habían sido operados de dos a cinco años antes. Los datos fueron recogidos por entrevistas semi-estructuradas y analizados según los conceptos de cultura y religión. Sintetizamos los resultados en tres categorias descriptivas: la representación moral del cáncer, las creencias religiosas en el trayecto del cáncer y la negociación con la religión por la supervivencia. El significado que resulta - "la expectativa por una segunda oportunidad" - enfatiza la importancia de la religión como parte de las redes de apoyo que se encadenan con la conciliación con el estigma del cáncer, con la expectativa de cura y con las formas de arreglar la vida cotidiana, en la supervivenvia.The objective of this exploratory study was to identify how religion influences the survival of a group of cancer patients. The study consisted of an ethnographic case with the participation of six laryngectomized male and female patients between 51 and 72 years old, who had been operated on two to five years earlier. Data were collected by semistructured interviews and analyzed on the basis of the concepts of culture and religion. The results were synthesized into three descriptive categories: the moral representation of cancer, religious beliefs about the cancer trajectory, and negotiation with religion for survival. These categories give rise to the meaning "the hope for a second chance", which emphasizes the importance of religion as part of the support networks that articulate with the patient's coping with the stigma of cancer, with the hope for cure, and with the ways of organizing everyday life, during survival

Use of Machine Learning and Wearable Sensors to Predict Energetics and Kinematics of Cutting Maneuvers

Changes of directions and cutting maneuvers, including 180-degree turns, are common locomotor actions in team sports, implying high mechanical load. While the mechanics and neurophysiology of turns have been extensively studied in laboratory conditions, modern inertial measurement units allow us to monitor athletes directly on the field. In this study, we applied four supervised machine learning techniques (linear regression, support vector regression/machine, boosted decision trees and artificial neural networks) to predict turn direction, speed (before/after turn) and the related positive/negative mechanical work. Reference values were computed using an optical motion capture system. We collected data from 13 elite female soccer players performing a shuttle run test, wearing a six-axes inertial sensor at the pelvis level. A set of 18 features (predictors) were obtained from accelerometers, gyroscopes and barometer readings. Turn direction classification returned good results (accuracy > 98.4%) with all methods. Support vector regression and neural networks obtained the best performance in the estimation of positive/negative mechanical work (coefficient of determination R-2 = 0.42-0.43, mean absolute error = 1.14-1.41 J) and running speed before/after the turns (R-2 = 0.66-0.69, mean absolute error = 0.15-018 m/s). Although models can be extended to different angles, we showed that meaningful information on turn kinematics and energetics can be obtained from inertial units with a data-driven approach

Kinematic algorithm to determine the energy cost of running with changes of direction

Changes of direction (CoDs) have a high metabolic and mechanical impact in field and court team sports, but the estimation of the associated workload is still inaccurate. This study aims at validating an algorithm based on kinematic data to estimate the energy cost of running with frequent 180\ub0-CoDs. Twenty-six physically active male subjects (22.4\u202f\ub1\u202f3.2\u202fyears) participated in two sessions: (1) maximum oxygen uptake (V\u307O2,max) and maximal aerobic speed (MAS) test; (2) 5-m continuous shuttle run (two 5-min trials at 50% and 75% MAS, 6-min recovery). In (2), full-body 3D-kinematics and V\u307O2 were simultaneously recorded. Actual cost of shuttle running (Cmeas) was obtained from the aerobic, anaerobic alactic and lactic components. The proposed algorithm detects "braking phases", periods of mostly negative (eccentric) work occurring at concurrent knee flexion and ground contact, and estimates energy cost (Cest) considering negative mechanical work in braking phases, and positive elsewhere. At the speed of, respectively, 1.54\u202f\ub1\u202f0.17 and 1.90\u202f\ub1\u202f0.15\u202fm\u202fs-1 (rate of perceived exertion: 9.1\u202f\ub1\u202f1.8 and 15.8\u202f\ub1\u202f1.9), Cmeas was 8.06\u202f\ub1\u202f0.49 and 9.04\u202f\ub1\u202f0.73\u202fJ\u202fkg-1\u202fm-1. Cest was more accurate than regression models found in literature (p\u202f\u202f0.05; average error: 8.3%, root-mean-square error: 0.86\u202fJ\u202fkg-1\u202fm-1). The proposed algorithm improved existing techniques based on CoM kinematics, integrating data of ground contacts and joint angles that allowed to separate propulsive from braking phases. This work constitutes the basis to extend the model from the laboratory to the field, providing a reliable measure of training and matches workload

Composição bromatológica, digestibilidade in vitro e produção de biomassa de leguminosas forrageiras lenhosas cutivadas em solo arenoso

Com o objetivo de avaliar o valor nutritivo e a produtividade das leguminosas forrageiras lenhosas: Albizia lebbeck (Albízia), Cajanus cajan (Feijão-Guandu), Cratylia argentea (Cratília), Gliricidia sepium (Gliricídia) e Leucaena leucocephala (Leucena), a serem utilizadas na suplementação de bovinos como banco de proteína, conduziu-se um experimento em Neossolo Quartzarênico. O experimento foi realizado entre março de 2006 e outubro de 2007. As avaliações foram realizadas em dois períodos (chuvoso e seco), com dois cortes para cada período. Não houve diferença no acúmulo de matéria seca nos cortes do período chuvoso para as espécies estudadas. Já no período seco de avaliação, a A. lebbeck e a C. argentea foram superiores às demais leguminosas. O C. cajan não se recuperou após os corte do período chuvoso, o que resultou em um baixo acúmulo de matéria seca nos cortes do período seco. As folhas da A. lebbeck apresentaram os maiores conteúdos de proteína bruta nos dois cortes dos períodos de avaliação (210 a 212 g/kg). A digestibilidade in vitro da matéria seca nas folhas da A. lebbeck foi superior, com valores médios de 568 g/kg. A. lebbeck, Cratylia argentea e Gliricidia sepium apresentaram os maiores conteúdos para digestibilidade das hastes finas. A. lebbeck e C. argentea apresentaram acúmulo de massa seca superior às demais espécies testadas (19,3 e 24,3 t/ha, respectivamente) e ainda, os melhores valores para as características qualitativas. Essas duas últimas são as espécies mais promissoras e adaptadas para a formação de bancos de proteínas nesses tipos de solos

Uso de produtos naturais para proteção de mudas na arborização de pastagens.

Os sistemas de produção convencional têm esgotado os recursos ambientais, o que torna o agroecossistema frágil e insustentável. Sistemas silvipastoris podem ser alternativas viáveis na recuperação de pastagens degradadas. Este estudo foi desenvolvido com o objetivo de avaliar produtos naturais na implantação de espécies arbóreas em pastagens com presença constante de bovinos, sem proteção física das mudas. O experimento foi conduzido na Embrapa Gado de Corte, Campo Grande, MS, no período de 02/02/2005 a 28/03/2005. O delineamento utilizado foi de parcelas subdivididas inteiramente ao acaso, com dez repetições. As parcelas foram: 1) fezes bovinas ao redor da muda, 2) sangue bovino seco, 3) ovo sem casca e 4) testemunha sem proteção. As subparcelas foram cinco especies arbóreas: Myroxylon peruiferum (Bálsamo), Dipteryx alata (Cumbaru), Schizolobium parahyba (Guapuruvu), Genipa americana (Jenipapo) e Mimosa caesalpineaefolia (Sansão do campo). A herbivoria foi intensa em todos os tratamentos. A S. parahyba apresentou taxa de sobrevivência de 72,5%, enquanto 100% das plantas da M. caesalpineafolia morreram. Há indícios de que a maior proteção, embora parcial, foi dada pela aplicação de fezes ao redor da muda. As aspersões de sangue ou de ovo não ofereceram proteção às árvores jovens. A concentração e a freqüência de aplicação das fezes é uma alternativa que merece maiores estudos