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Objectives: To evaluate the differences in strength and mobility of shoulder rotator muscles in the dominant and non-dominant shoulders of elite volleyball players.Methods: Isokinetic muscle strength tests were performed at speeds of 60 and 120 degrees/s, and shoulder mobility was examined in ten players from the England national men's volleyball squad. The subjects also completed a questionnaire that included a visual prompt and analogue pain scale.Results: The range of motion of internal rotation on the dominant side was less than that on the non-dominant side (p < 0.01). The average peak strength at 60 degrees/s external eccentric contraction was lower than that of internal concentric contraction in the dominant arm, but was higher in the non-dominant arm. Six of the ten subjects reported a shoulder problem, described as a diffuse pain located laterally on the dominant shoulder.Conclusions: These elite volleyball players had a lower range of motion (internal rotation) and relative muscle imbalance in the dominant compared with the non-dominant shoulder. [ABSTRACT FROM AUTHOR]

At the hillslope profile and/or field scale, a simple Windows graphical user interface (GUI) is available to easily specify the slope, soil, and management inputs for application of the USDA Water Erosion Prediction Project (WEPP) model. Likewise, basic small watershed configurations of a few hillslopes and channels can be created and simulated with this GUI. However, as the catchment size increases, the complexity of developing and organizing all WEPP model inputs greatly increases due to the multitude of potential variations in topography, soils, and land management practices. For these types of situations, numerical approaches and special user interfaces have been developed to allow for easier WEPP model setup, utilizing either publicly available or user-specific geospatial information, e.g., digital elevation models (DEMs), geographic information system (GIS) soil data layers, and GIS land use/land cover data layers. We utilize the Topographic Parameterization (TOPAZ) digital landscape analysis tool for channel, watershed, and sub-catchment delineation and to derive slope inputs for each of the subcatchment hillslope profiles and channels. A user has the option of specifying a single soil and land management for each subcatchment or utilizing the information in soils and land use/land cover GIS data layers to automatically assign those values for each grid cell. Once WEPP model runs are completed, the output data are analyzed, results interpreted, and maps of spatial soil loss and sediment yields are generated and visualized in a GIS. These procedures have been used within a number of GIS platforms including GeoWEPP, an ArcView/ArcGIS extension that was the first geospatial interface to be developed in 2001. GeoWEPP allows experienced GIS users the ability to import and utilize their own detailed DEM, soil, and/or land use/land cover information or to access publicly available spatial datasets. A web-based GIS system that used MapServer web GIS software for handling and displaying the spatial data and model results was initially released in 2004. Most recently, Google Maps and OpenLayers technologies have been integrated into the web WEPP GIS software to provide significant enhancements. This article discusses in detail the logic and procedures for developing the WEPP model inputs, the various WEPP GIS interfaces, and provides example real-world geospatial WEPP applications. Further work is ongoing in order to expand these tools to allow users to customize their own inputs via the internet and to link the desktop GeoWEPP with the web-based GIS system. [ABSTRACT FROM AUTHOR]

Eroded soil from hillslopes will deposit downslope or be transferred to waterways and deposited downstream. Understanding the interactions between shallow flows in a rill and factors such as slope, rainfall intensity, infiltration, and incoming sediment concentration are important in determining where and when sediment will be deposited. The main objectives of this study were to determine how these factors affect the deposition of non-cohesive sediment under shallow water flow in a rill and to test whether the β turbulence parameter in the WEPP model deposition equation was adequately represented for those conditions. An experimental laboratory hydraulic flume under rainfall simulators was used to study sediment deposition in a 25 cm wide by 3.6 m long rill A laser scanner was used to quantify deposition after each experiment, and sediment samples were taken from the flume outlet to quantify sediment transport. The experiments were conducted using silica sand, glass beads, and artificial plastic/glass aggregates. Combinations of different flow rates, rainfall intensities, and sediment feed rates were studied for each sediment type at slopes varying from 1% to 5%. The interaction of rainfall intensity and flow depths had a more significant effect on deposition of particles of low specific gravity and under greater interrill sediment contributions; however, this was not true for denser sand particles. Sediment deposition in the rill was less under no rainfall and high-intensity rainfall than under medium-intensity rainfall. The effect of infiltration on sediment deposition under high-intensity rainfall was related to the slope steepness. At slopes greater than 3%, less deposition was observed under saturated conditions than under unsaturated conditions. The opposite was true for slopes less than 3%. Modeling deposition based on measured deposition rates of the non-cohesive sediment showed that the fl turbulence factor for the particle and flow conditions in these experiments could be 10 or more times less than the 0.5 value currently used in the WEPP deposition equation. [ABSTRACT FROM AUTHOR]