Prediction of grip and key pinch strength in 978 healthy subjects

<p>Abstract</p> <p>Background</p> <p>Hand strength is an important independent surrogate parameter to assess outcome and risk of morbidity and mortality. This study aimed to determine the predictive power of cofactors and to predict population-based normative grip and pinch strength.</p> <p>Methods</p> <p>A representative population survey was used as the basis for prediction analyses (n = 978). Bivariate relationships between grip/pinch strengths of the dominate hand were explored by means of all relevant mathematical functions to maximize prediction. The resulting best functions were combined into a multivariate regression.</p> <p>Results</p> <p>Polynoms (up to the third degree) were the best predictive functions. On the bivariate level, height was best correlated to grip (46.2% explained variance) and pinch strength (37.7% explained variance) in a linear relationship, followed by sex, age, weight, and occupational demand on the hand. Multivariate regression provided predicted values close to the empirical ones explaining 76.6% of the variance for grip strength and 67.7% for pinch strength.</p> <p>Conclusion</p> <p>The five easy-to-measure cofactors sex, age, body height, categorized occupational demand on the hand, and body weight provide a highly accurate prediction of normative grip and pinch strength.</p

Tensile properties of spark plasma sintered AISI 316L stainless steel with unimodal and bimodal grain size distributions

International audiencePowder metallurgy associated to spark plasma sintering was used to elaborate near full-dense samples of 316L austenitic stainless steel with unimodal or bimodal grain size distributions. To this aim, two different precursor powders were employed: a ball-milled one giving rise to ultrafine grains and a coarse one, as-received, for grains with conventional size. Sintered specimens were characterized in mechanical tension and their microstructure was revealed using transmission and scanning electron microscopy. Unimodal ultrafine grained samples show a large yield stress and a low ductility with a breakdown in the Hall-Petch relationship. For bimodal samples, a compromise between yield stress and ductility can be found. These features are then discussed in terms of strain mechanisms, grain size distribution and backstress. It is shown in particular that coarse grains contribute to enhance the ductility of the ultrafine grains matrix by modifying both the strain hardening mechanisms and the stress concentration areas

Elaboration of austenitic stainless steel samples with bimodal grain size distributions and investigation of their mechanical behavior

Samples of 316L austenitic stainless steel with bimodal grain size distributions are elaborated using two distinct routes. The first one is based on powder metallurgy using spark plasma sintering of two powders with different particle sizes. The second route applies the reverse-annealing method: it consists in inducing martensitic phase transformation by plastic strain and further annealing in order to obtain two austenitic grain populations with different sizes. Microstructural analy ses reveal that both methods are suitable to generate significative grain size contrast and to control this contrast according to the elaboration conditions. Mechanical properties under tension are then characterized for different grain size distributions. Crystal plasticity finite element modelling is further applied in a configuration of bimodal distribution to analyse the role played by coarse grains within a matrix of fine grains, considering not only their volume fraction but also their spatial arrangemen

Elaboration of austenitic stainless steel samples with bimodal grain size distributions and investigation of their mechanical behavior

International audienc

Tensile properties of spark plasma sintered AISI 316L stainless steel with unimodal and bimodal grain size distributions

International audienc