Kinematics of the typical beach flags start for young adult sprinters

This study profiled beach flags start kinematics for experienced young adult sprinters. Five males and three females (age = 20.8 ± 2.1 years; height = 1.70 ± 0.06 meters [m]; mass = 63.9 ± 6.0 kilograms) completed four sprints using their competition start technique. A high-speed camera, positioned laterally, filmed the start. Data included: start time; hand clearance time; posterior movement from the start line; feet spacing during the start; elbow, hip, knee, trunk lean, and trajectory angles at take-off; and first step length. Timing gates recorded 0-2, 0-5, and 0-20 m time. Spearman's correlations identified variables relating (p < 0.05) to faster start and sprint times. The beach flags start involved sprinters moving 0.18 ± 0.05 m posterior to the start line by flexing both legs underneath the body before turning. Following the turn, the feet were positioned 0.47 ± 0.07 apart. This distance negatively correlated with start (ρ = -0.647), 0-2 (ρ = -0.683), and 0-5 m (ρ = -0.766) time. Beach flags start kinematics at take-off resembled research analyzing track starts and acceleration. The elbow extension angle (137.62 ± 13.45°) of the opposite arm to the drive leg correlated with 0-2 (ρ = -0.762), 0-5 (ρ = -0.810), and 0-20 m (ρ = -0.810) time. Greater arm extension likely assisted with stability during the start, leading to enhanced sprint performance. The drive leg knee extension angle (146.36 ± 2.26°) correlated with start time (ρ = -0.677), indicating a contribution to a faster start completion. A longer first step following the start related to faster 0-5 m time (ρ = -0.690). Sprinters quicker over 0-2 and 0-5 m were also quicker over 20 m (ρ = 0.881-0.952). Beach flags sprinters must ensure their start is completed quickly, such that they can attain a high speed throughout the race

Le and la:struggle of genders?

This article deals with the variation of the use of the Spanish oblique pronouns le and la. This article aims to demonstrate that the gender of the referents and their cultural status plays a decisive role in the selection of these pronouns in one of the main works of Miguel Delibes, Cinco Horas con Mario (1963)

Le and la:struggle of genders?

This article deals with the variation of the use of the Spanish oblique pronouns le and la. This article aims to demonstrate that the gender of the referents and their cultural status plays a decisive role in the selection of these pronouns in one of the main works of Miguel Delibes, Cinco Horas con Mario (1963)

Adenosine, carbohydrates, and ischemic preconditioning

In order to sustain nomml function, the heart is dependent on an adequate delivery of oxygen and substrates to the heart to m

Psychiatric comorbidity and causal disease models

In psychiatry, comorbidity is the rule rather than the exception. Up to 45% of all patients are classified as having more than one psychiatric disorder. These high rates of comorbidity have led to a debate concerning the interpretation of this phenomenon. Some authors emphasize the problematic character of the high rates of comorbidity because they indicate absent zones of rarities. Others consider comorbid conditions to be a validator for a particular reclassification of diseases. In this paper we will show that those at first sight contrasting interpretations of comorbidity are based on similar assumptions about disease models. The underlying ideas are that firstly high rates of comorbidity are the result of the absence of causally defined diseases in psychiatry, and second that causal disease models are preferable to non-causal disease models. We will argue that there are good reasons to seek after causal understanding of psychiatric disorders, but that causal disease models will not rule out high rates of comorbidity-neither in psychiatry, nor in medicine in general. By bringing to the fore these underlying assumptions, we hope to clear the ground for a different understanding of comorbidity, and of models for psychiatric diseases. (C) 2012 Elsevier Inc. All rights reserved.</p