Gait initiation is the task commonly used to investigate the anticipatory postural adjustments necessary to begin a new gait cycle from the standing position. In this study, we analyzed whether and how foot-floor interface characteristics influence the gait initiation process. For this purpose, 25 undergraduate students were evaluated while performing a gait initiation task in three experimental conditions: barefoot on a hard surface (barefoot condition), barefoot on a soft surface (foam condition), and shod on a hard surface (shod condition). Two force plates were used to acquire ground reaction forces and moments for each foot separately. A statistical parametric mapping (SPM) analysis was performed in COP time series. We compared the anterior-posterior (AP) and medial-lateral (ML) resultant center of pressure (COP) paths and average velocities, the force peaks under the right and left foot, and the COP integral x force impulse for three different phases: the anticipatory postural adjustment (APA) phase (Phase 1), the swing-foot unloading phase (Phase 2), and the support-foot unloading phase (Phase 3). In Phase 1, significantly smaller ML COP paths and velocities were found for the shod condition compared to the barefoot and foam conditions. Significantly smaller ML COP paths were also found in Phase 2 for the shod condition compared to the barefoot and foam conditions. In Phase 3, increased AP COP velocities were found for the shod condition compared to the barefoot and foam conditions. SPM analysis revealed significant differences for vector COP time series in the shod condition compared to the barefoot and foam conditions. The foam condition limited the impulse-generating capacity of COP shift and produced smaller ML force peaks, resulting in limitations to body-weight transfer from the swing to the support foot. The results suggest that footwear and a soft surface affect COP and impose certain features of gait initiation, especially in the ML direction of Phase 1.

Objetivo: compreender o desenvolvimento do ajuste postural antecipatório na inicialização da marcha no desenvolvimento do andar independente em crianças típicas. Participantes: 50 crianças divididas em: G1- 1.3 anos, G2- 2 anos, G3- 3 anos e G4- 4 anos. Variáveis: Amplitude de deslocamento anteroposterior (COPAP) e mediolateral (COPML) do centro de pressão (COP), velocidade média de deslocamento do COP nas direções anteroposterior e mediolateral (VELAP e VELML) durante as fases da inicialização do passo. Resultados: COPAP_1, COPAP_2 e COPAP_3 foram maiores no grupo G1, VELAP_1 e VELAP_2 no G1 são maiores. Conclusão: Com a experiência do andar independente a criança torna-se mais habilidosa devido ao aprimoramento de sua capacidade para avaliar as condições do ambiente.

The variables analyzed showed minor differences and do not constitute an imminent risk for the stability dynamics of pregnant woman.

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n5p611 The aim of the present study was to analyze the association between variables of the game on the offensive structure from the zone in which attack is performed in high-level Men’s volleyball. The sample was composed by 12 teams, with the analysis of 142 games, which totalized 19,545 reception, set and attack actions. Data analyses were run with descriptive statistic and the qui-quadratic test for searching association between the variables. The results showed association between tempo of attack and attack effect, type of attack and attack zone and attack zone and tempo of attack and attack effect. It was concluded that Brazilian teams underuse backcourt attacks, and the offensive structure accomplished through the faster game, which is mainly important on attacks carried out in positions 2, 3 and 4. Furthermore, the reception quality proved to be the precursor factor in the construction of attack. It was also observed that there was no 1st tempo of attacks from the backcourt, indicating that it is necessary to change the type of game, specifically with the increment of the speed of sets conducted by the backcourt.

Three-dimensional analysis in horses has been widely used in the past years due to technological advancement. With the objective of conducting a literature review of the applicability of existing evidence in horses of a biomechanical model focusing on three-dimensional kinematics and its production in Veterinary Medicine, we searched in the databases: ScienceDirect, SciELO and PubMed. To access them, using as key-words: "Three-dimensional kinematic model in equines", "equine kinematic analysis", "biomechanics of equine locomotion", "equine kinematic model". Selection criteria were papers published between: paper published between 1990 and 2020, in English, with free electronic access and in which characteristics of a three-dimensional kinematic model in horses were mentioned. Most studies were experimental, and population included both healthy horses and pathological ones. Three-dimensional kinematic model was used mainly to understand the analysed movement and using as model the full body. There is scientific evidence on the use of biomechanical models for three-dimensional kinematic analysis in horses published in the period studied, used by professionals in veterinary medicine. The objectives of using the model were specific to the type of movement or pathology of the horse and consistent with the characteristics of the studies.