Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

Background: The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. Methods: Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). Results: Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the noninjured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. Conclusions: This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases

The impact of the institutional environment on the value relevance of fair values

Most prior studies attribute valuation discounts on certain fair valued assets to measurement error or bias. We argue that institutional differences across countries (e.g., information environment or market sophistication) affect investors’ ability to process and impound fair value information in their valuation. We predict that the impact of the institutional environment on value relevance is particularly pronounced for reported fair values of assets designated at fair value through profit or loss (hereafter, “FVO assets”), for which investor experience is lowest and complexity is highest. Using a global sample of IFRS banks, we find that FVO assets are generally less value relevant than held-for-trading assets (HFT) and available-for-sale assets (AFS). By partitioning countries into market- and bank-based economies to proxy for institutional differences, we find that the valuation discount on FVO assets is more pronounced in bank-based economies. Additional tests suggest that this valuation discount is attenuated by a richer firm-level information environment and the presence of institutional investors with fair value experience

Retail Grocery Salary Control: A Linear Programming Model

We developed a Linear Programming model to determine the optimum mix and numbers of employees required, and to minimize the weekly salary cost of an average supermarket operating in Portlan

Studies in Radar Cross-Sections - XVIII; Airborne passive measures and countermeasures

http://deepblue.lib.umich.edu/bitstream/2027.42/21172/2/rl2047.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/21172/1/rl2047.0001.001.tx