Effects of a sand running surface on the kinematics of sprinting at maximum velocity

Performing sprints on a sand surface is a common training method for improving sprint-specific strength. For maximum specificity of training the athlete’s movement patterns during the training exercise should closely resemble those used when performing the sport. The aim of this study was to compare the kinematics of sprinting at maximum velocity on a dry sand surface to the kinematics of sprinting on an athletics track. Five men and five women participated in the study, and flying sprints over 30 m were recorded by video and digitized using biomechanical analysis software. We found that sprinting on a sand surface was substantially different to sprinting on an athletics track. When sprinting on sand the athletes tended to ‘sit’ during the ground contact phase of the stride. This action was characterized by a lower center of mass, a greater forward lean in the trunk, and an incomplete extension of the hip joint at take-off. We conclude that sprinting on a dry sand surface may not be an appropriate method for training the maximum velocity phase in sprinting. Although this training method exerts a substantial overload on the athlete, as indicated by reductions in running velocity and stride length, it also induces detrimental changes to the athlete’s running technique which may transfer to competition sprinting

Preventing the onset of major depression based on the level and profile of risk of primary care attendees: protocol of a cluster randomised trial (the predictD-CCRT study)

BACKGROUND: The 'predictD algorithm' provides an estimate of the level and profile of risk of the onset of major depression in primary care attendees. This gives us the opportunity to develop interventions to prevent depression in a personalized way. We aim to evaluate the effectiveness, cost-effectiveness and cost-utility of a new intervention, personalized and implemented by family physicians (FPs), to prevent the onset of episodes of major depression. METHODS: This is a multicenter randomized controlled trial (RCT), with cluster assignment by health center and two parallel arms. Two interventions will be applied by FPs, usual care versus the new intervention predictD-CCRT. The latter has four components: a training workshop for FPs; communicating the level and profile of risk of depression; building up a tailored bio-psycho-family-social intervention by FPs to prevent depression; offering a booklet to prevent depression; and activating and empowering patients. We will recruit a systematic random sample of 3286 non-depressed adult patients (1643 in each trial arm), nested in 140 FPs and 70 health centers from 7 Spanish cities. All patients will be evaluated at baseline, 6, 12 and 18 months. The level and profile of risk of depression will be communicated to patients by the FPs in the intervention practices at baseline, 6 and 12 months. Our primary outcome will be the cumulative incidence of major depression (measured by CIDI each 6 months) over 18 months of follow-up. Secondary outcomes will be health-related quality of life (SF-12 and EuroQol), and measurements of cost-effectiveness and cost-utility. The inferences will be made at patient level. We shall undertake an intention-to-treat effectiveness analysis and will handle missing data using multiple imputations. We will perform multi-level logistic regressions and will adjust for the probability of the onset of major depression at 12 months measured at baseline as well as for unbalanced variables if appropriate. The economic evaluation will be approached from two perspectives, societal and health system. DISCUSSION: To our knowledge, this will be the first RCT of universal primary prevention for depression in adults and the first to test a personalized intervention implemented by FPs. We discuss possible biases as well as other limitations.Trial registration: ClinicalTrials.gov identifier: NCT01151982

Trastorno Delirante 2021

A pesar de ser un diagnóstico fiable y válido, en las últimas décadas ha habido una confusión en la terminología utilizada para describir al trastorno delirante y una controversia acerca de la uti- lidad de clasificar el trastorno en subtipos según el contenido. El principal objetivo de esta revisión es resumir la evidencia en datos epidemiológicos, clínicos y resultados terapéuticos. La prevalencia del trastorno delirante es baja (0.03%) aunque es más elevada en los servicios de urgencias y en población penitenciaria. El fenómeno psicopatológico elemental del trastorno delirante es la significación personal patológica o mórbida que diferencia el “delirio del paranoi- co” del delirio del esquizofrénico o el delirio afectivo. Los estudios centrados en las trayectorias evolutivas del trastorno delirante des- criben tasas de estabilidad diagnóstica cercanas al 80%. Autores clásicos definen dos fenotipos principales que pueden ser útiles para los clínicos: 1) Paranoia vera (similar al delirio interpretativo) y 2) Paranoia querulans (delirio reivindicativo). Existe una importante controversia acerca de la respuesta farmacológica en el trastorno delirante. La revisión sistemática más reciente reporta unas tasas de respuesta entre el 5-50%. Existe un escaso consenso sobre las definiciones operativas de la respuesta antipsicótica que podría explicar, en parte, la heterogeneidad de los datos. La identificación de factores predictores de la respuesta antipsicótica en el trastor- no delirante puede ayudar a mejorar los resultados clínicos. Son considerados factores moderadores de la respuesta: edad, género, estado reproductivo, comorbilidad, estructura cerebral y variantes genéticas en genes que codifican para receptores dopaminérgicos y proteínas implicadas en la metabolización de los psicofármacos. Factores mediadores de la respuesta: niveles plasmáticos de antip- sicóticos, cambios funcionales cerebrales y niveles hormonales. El problema de la adherencia terapéutica en estos pacientes es uno de los mayores desafíos en el campo del trastorno delirante