THE CHOICE OF TRAINING FOOlWEAR HAS AN EFFECT ON CHANGES :IN MORPHOLOGY AND FUNCTION OF FOOT AND SHANK MUSCLES

The use of minimal footwear leads to higher muscle activity of the M. flexor hallucis longus and to a higher range of motion in the metatarsophalangeal joints (MPJ). This could lead to training effects of in-and extrinsic foot structures as muscles and tendons. The purpose of the study was to determine whether muscle strength or the anatomical cross sectional area of foot and shank muscles are affected by the use of minimal footwear. In a longitudinal prospective intervention study the effect of the use of a minimal shoe was evaluated. Therefore isometric MPJ f1exion strength, inversion strength and plantar f1exion strength were determined. The effect on the anatomical cross sectional areas (ACSA) of selected foot and shank muscles were measured using MRI. ACSA as well as muscular performance increased significantly using the minimal shoe in comparison to conventional footwear. This should lead to performance enhancement and injury prevention

DETERMINANTS OF ACCELERATION PERFORMANCE IN ELITE FEMALE SPRINTERS

The purpose of this study was to explore the determinants of performance in the early acceleration phase (first four meters) in nine elite female sprinters. Acceleration performance was quantified using a modified version of the normalized average horizontal block power. Ground reaction forces were collected using an instrumented starting block and three force plates. In addition, full body kinematics were captured using an optoelectronic motion capture system. The results indicate that a starting technique facilitating a horizontal push-off direction and force application with short contact times is beneficial for starting performance. This might be achieved through a greater forward lean of the body. Previously proposed beneficial effects of an active touchdown of the foot could not be confirmed in the present study

LEG- AND JOINT STIFFNESS IN MALE ELITE HIGH JUMP: THE INFLUENCE OF STIFFNESS ON SPORTS PERFORMANCE

The purpose of this study was to analyse stiffness in the mechanical system of the world’s elite high jumpers. Seven male elite high jump athletes (personal best 2.24 m ± 0.06 m) were filmed with 19 Infrared-High-Speed-Cameras during jumping. Kinetics were captured with a force plate. It was found that a different leg and joint stiffness during takeoff enables nearly the same jumping height. For example, a typical power jumper with a leg stiffness of 543.6 N m-1 kg-1 reached 2.13 m, while a typical speed jumper with a leg stiffness of 1133.5 N m-1 kg-1 reached a comparable height of 2.12 m. Therefore, it seems that sports performance in single leg jumping is not limited by athlete’s leg and joint stiffness in a small group of male elite high jumpers

Sprint start kinetics of amputee and non-amputee sprinters

The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58–14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70–12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (−33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (−17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs

Die Fälle Edward Snowden und Julian Assange

Die Themen Edward Snowden und Julian Assange werden sowohl unter völker- und europarechtlichen, als auch unter innerstaatlichen Gesichtspunkten betrachtet und es wird anhand von einschlägigen Fällen aus der Judikatur aufgezeigt, wie ähnlich gelagerte Fälle rund um die Themen Asyl und Gewährung von weiteren Menschenrechten entschieden wurden.eingereicht von Braunstein BjörnUniversität Linz, Diplomarbeit, 2017(VLID)191539

Comparison of Different Training Algorithms for the Leg Extension Training with an Industrial Robot

In the past, different training scenarios have been developed and implemented on robotic research platforms, but no systematic analysis and comparison have been done so far. This paper deals with the comparison of an isokinematic (motion with constant velocity) and an isotonic (motion against constant weight) training algorithm. Both algorithms are designed for a robotic research platform consisting of a 3D force plate and a high payload industrial robot, which allows leg extension training with arbitrary six-dimensional motion trajectories. In the isokinematic as well as the isotonic training algorithm, individual paths are defined i n C artesian s pace by sufficient s upport p oses. I n t he i sotonic t raining s cenario, the trajectory is adapted to the measured force as the robot should only move along the trajectory as long as the force applied by the user exceeds a minimum threshold. In the isotonic training scenario however, the robot’s acceleration is a function of the force applied by the user. To validate these findings, a simulative experiment with a simple linear trajectory is performed. For this purpose, the same force path is applied in both training scenarios. The results illustrate that the algorithms differ in the force dependent trajectory adaption

A novel guideline for the analysis of linear acceleration mechanics – outlining a conceptual framework of ‘shin roll’ motion

Linear acceleration is a key performance determinant and major training component of many sports. Although extensive research about lower limb kinetics and kinematics is available, consistent definitions of distinctive key body positions, the underlying mechanisms and their related movement strategies are lacking. The aim of this ‘Method and Theoretical Perspective’ article is to introduce a conceptual framework which classifies the sagittal plane ‘shin roll’ motion during accelerated sprinting. By emphasising the importance of the shin segment’s orientation in space, four distinctive key positions are presented (‘shin block’, ‘touchdown’, ‘heel lock’ and ‘propulsion pose’), which are linked by a progressive ‘shin roll’ motion during swing-stance transition. The shin’s downward tilt is driven by three different movement strategies (‘shin alignment’, ‘horizontal ankle rocker’ and ‘shin drop’). The tilt’s optimal amount and timing will contribute to a mechanically efficient acceleration via timely staggered proximal-to-distal power output. Empirical data obtained from athletes of different performance levels and sporting backgrounds are required to verify the feasibility of this concept. The framework presented here should facilitate future biomechanical analyses and may enable coaches and practitioners to develop specific training programs and feedback strategies to provide athletes with a more efficient acceleration technique