The Single Leg Bridge Test (SLBT) as a field test to measure hamstring strength in young footballers

Purpose The muscle strength of the hamstrings is often reported as asymmetric in footballers and is associated with the occurrence of muscle injuries. Therefore, discriminating, reproducible and valid screening tests are sought. Methodology The objectives of this study were: to assess the muscle strength profile of the hamstrings with the Single Leg Bridge Test (SLBT) in U17 and U19 football players, to calculate the asymmetry of muscle strength and to classify the results according to 3 performance levels. This cross-sectional study included 37 young footballers, 20 U17 and 17 U19. The SLBT was performed for the left and right leg. History of hamstring muscle injury has been identified up to 2 years prior to SLBT. Results A significant difference was found between the left and right side (P = 0.01), particularly among U17s (P = 0.03). The asymmetry of strength was 23% for the U17s and 17% for the U19s. The performance considered “poor” (21–30 repetitions) was different between U17 and U19 (P < 0.05). No association was found with a history of hamstring muscle injury. Conclusion The SLBT is an adequate field test for the assessment of hamstring strength in order to detect hamstring muscle asymmetry in young footballers. This test requires little equipment, money, and can be performed on multiple players simultaneously. Classification according to performance (number of repetitions) adds practical value in order to develop individual muscle building programs based on the calculated asymmetry in the young footballers

An integrated system for interactive continuous learning of categorical knowledge

This article presents an integrated robot system capable of interactive learning in dialogue with a human. Such a system needs to have several competencies and must be able to process different types of representations. In this article, we describe a collection of mechanisms that enable integration of heterogeneous competencies in a principled way. Central to our design is the creation of beliefs from visual and linguistic information, and the use of these beliefs for planning system behaviour to satisfy internal drives. The system is able to detect gaps in its knowledge and to plan and execute actions that provide information needed to fill these gaps. We propose a hierarchy of mechanisms which are capable of engaging in different kinds of learning interactions, e.g. those initiated by a tutor or by the system itself. We present the theory these mechanisms are build upon and an instantiation of this theory in the form of an integrated robot system. We demonstrate the operation of the system in the case of learning conceptual models of objects and their visual properties