São os podzóis dominantes nas formações arenosas do litoral português ? O caso da Mata Nacional de Leiria

The knowledge on the Podzols which occur in Portugal is scarce. Besides its morphological characterization, their actual extension and distribution are unknown, and its taxonomy is controversial. Therefore, 22 pedons formed under conditions considered representative of those in which Podzols mostly occur in the country were selected in the Mata Nacional de Leiria, and their morphological, physical, chemical and mineralogical characteristics were studied. Soils developed in such conditions are both Podzols and Arenossolos sensu WRB 2006, but the latter are clearly predominant. The Podzols frequently show thick albic horizons and incipient spodic horizons; the latter are dusky, but show organic matter (OM) contents close the minimum threshold considered as diagnostic criteria for spodic horizons, and low content in Al and Fe. A wide spectrum of characteristics is observed in the Arenosols. Some of them present profils with morphology close to that of the Podzols, but with a low illuvial acumulationb of OM (and Fe e Al components), and the others (the predominant Arenosols in the study area) do not present intergrade characteristics, although they can show expressed albic horizons. The former Arenosols correspond to intergrades of Podzols which are not satisfactorily fit into the recent WRB versions. The characteristics of Podzols are strongly dependent on the low weatherability and high permeability of the lithological substrate (non consolidated quartzeous sediments)

Kinematic and electromyographic analysis of the overhead squat in individuals showing excessive medial knee displacement

Dynamic knee valgus is a multi-planar motion that has been associated with anterior cruciate ligament injuries and patellofemoral pain syndrome. Clinical assessment of dynamic knee valgus can be made by looking for the visual appearance of excessive medial knee displacement (MKD) in the double-leg squat (DLS). The purpose of this dissertation was to identify the movement patterns and neuromuscular strategies associated with MKD during the DLS. Twenty-four control subjects and eight individuals showing MKD during the DLS participated in the study. Significant differences were verified between subjects that demonstrated MKD and a control (CON) group for the eletromyographic amplitude of adductor magnus, biceps femoris, vastus lateralis and vastus medialis muscles (p < 0.05), during the descending phase of the DLS. During the ascending phase were found group differences for adductor magnus and rectus femoris muscles (p < 0.05). Results from kinematic analysis revealed higher minimum and maximum values of ankle abduction and knee internal rotation angles (p < 0.05) for the MKD group. Also, individuals showing excessive MKD had higher hip adduction/abduction excursion. Our results suggested that higher tibial internal rotation and knee internal rotation angles in the initial position of the DLS are associated with MKD. The neuromuscular strategies that contributed to MKD were higher adductor magnus activation, whereas biceps femoris, vastus lateralis and vastus medialis activated more to stabilize the knee in response to the internal rotation moment.