Impact of Patellar Tendinopathy on Isokinetic Knee Strength and Jumps in Professional Basketball Players

Patellar tendinopathy is characterized by tendon pain which may reduce the level of performance. This study’s main aim was to compare isokinetic knee strength and jump performances at the start of the sport season between players with patellar tendinopathy and those without. Secondary aims were to assess the relationship between knee strength and jump function. Sixty-two professional basketball players were enrolled (mean age: 25.0 ± 4.0). All players performed knee isokinetic measurements, single leg countermovement jumps, and one leg hop tests. Correlations between knee strength and jump performances were examined. Twenty-four players declared a patellar tendinopathy and were compared to the 38 players without tendinopathy. The isokinetic quadriceps strength was lower in cases of patellar tendinopathy, and a camel’s back curve was observed in 58% of the cases of patellar tendinopathy. However, jump performances were preserved. No link was found between quadriceps and hamstring limb symmetry indexes at 60 and 180°/s with jumps. This preseason screening enabled us to identify the absence of consequences of patellar tendinopathy in professional basketball players. Jump performances were not altered, possibly due to compensatory strategies.

POSITIONAL IMPULSE AND DISCONTINUOUS CONTROLS FOR DIFFERENTIAL INCLUSION

Nonlinear control systems presented in the form of differential inclusions with impulse or discontinuous positional controls are investigated. The formalization of the impulse-sliding regime is carried out. In terms of the jump function of the impulse control, the differential inclusion is written for the ideal impulse-sliding regime. The method of equivalent control for differential inclusion with discontinuous positional controls is used to solve the question of the existence of a discontinuous system for which the ideal impulse-sliding regime is the usual sliding regime. The possibility of the combined use of the impulse-sliding and sliding regimes as control actions in those situations when there are not enough control resources for the latter is discussed.

On the Effect of Material Properties Uncertainty on the Magnitude of Temperature Oscillations in Two-Component Periodic Laminate: Tolerance Averaging Modelling

Over last decades composite materials gained even more interests in many industries due to theirs effective properties which may be apparently different (better) then constituents itself. By specific layout and distribution of composite components we can achieve desired properties in macro scale, e.g. high elasticity and low conductivity at the same time. On all interfaces, by perfect contact between phases, there will appear jump of gradient field (displacement or temperature) of unknown magnitude. This magnitude depends in fact, for the heat transfer problem, inter alia on the ratio of conductivities of composite constituents lying next to interface. Values of these oscillation magnitudes are case of our study here. The conductor under considerations is a two-phase, periodic laminate subjected to initial-boundary conditions assuring unidirectional heat flow, perpendicular to the laminas. Ratios of material properties are assumed as random variables of known probabilistic distribution. We will give an answer to the question: is the jump function of temperature gradient a random variable of Gaussian distribution In order to have a good description to considered problem we have decided on the use of tolerance averaging technique.

On the Connection between Spherical Laplace Transform and Non-Euclidean Fourier Analysis

We prove that, if the coefficients of a Fourier–Legendre expansion satisfy a suitable Hausdorff-type condition, then the series converges to a function which admits a holomorphic extension to a cut-plane. Next, we introduce a Laplace-type transform (the so-called Spherical Laplace Transform) of the jump function across the cut. The main result of this paper is to establish the connection between the Spherical Laplace Transform and the Non-Euclidean Fourier Transform in the sense of Helgason. In this way, we find a connection between the unitary representation of SO ( 3 ) and the principal series of the unitary representation of SU ( 1 , 1 ) .

Effect of surface tension on the antiplane deformation of bimaterial with a thin interface microinclusion

Within the framework of the concept of micromechanics, a method for taking into account the effect of surface energy for a thin interface micro-inclusion in the bimaterial under conditions of longitudinal shear has been proposed. The possibility of non-ideal contact between inclusion and matrix is provided, in particular, tension contact. This significantly extends the scope of applicability of the results. A generalized model of a thin inclusion with arbitrary elastic mechanical properties was built. Based on the application of the theory of functions of a complex variable and the jump function method, the stress field in the vicinity of the inclusion during its interaction with the screw dislocation was calculated. Several effects have been identified that can be used to optimize the energy parameters of the problem.