Sigrid Thaller

The effect of individual neuromuscular properties on performance in sports

We present a mathematical formulation of notions used in training science such as sports performance, performance determining factor and performance limiting factor. We give an example of model equations describing the relationship between individual neuromuscular properties and the associated performance in sports. An essential factor in modelling human movements is to determine the values of the subjects properties individually and in vivo. We perform measurements and identify the parameters describing the persons properties in the model equation. Simulations show effects of individual differences in the neuromuscular properties on the performance. Furthermore, we show the influence of changes in movement conditions on the performance.

Determination of individual knee-extensor properties from leg extensions and parameter identification

ABSTRACT Neural commands control skeletal muscles that act on passive structures and regulate voluntary movements. Mathematical models can simulate such movements and therefore require the knowledge of neuromuscular properties. In contrast to scaling these properties to the individual, we present a non-linear parameter identification method to determine them non-invasively and in vivo. The classic model A describes an excitable contractile element (CE) embedded in a geometrical representation of the leg. Its extension model B is used to study the effects of the force–length relationship and the serial elastic element (SEE). We show the validation of model B and discuss the quality of neuromuscular properties identified from simulations and experiments. The main finding is that identifications that consider CE–SEE dynamics result in increased and more realistic curvatures of the force–velocity relations. This shows that CE and SEE work interdependently and we recommend to co-ordinate the parameter values of muscle–tendon units.

Model-based analysis of fatigued human knee extensors

This study investigated the effect of isometrically induced fatigue on Hill-type muscle model parameters and related task-dependent effects. Parameter identification methods were used to extract fatigue-related parameter trends from isometric and ballistic dynamic maximum voluntary knee extensions. Nine subjects, who completed ten fatiguing sets, each consisting of nine 3 s isometric maximum voluntary contractions with 3 s rest plus two ballistic contractions with different loads, were analyzed. Only at the isometric task, the identified optimized model parameter values of muscle activation rate and maximum force generating capacity of the contractile element decreased from

Biomechanical muscle properties and angiotensin-converting enzyme gene polymorphism: a model-based study.

20.8 \pm 8.4

The relation between Hill's equation and individual muscle properties

20.8±8.4 to

Was leistet ein Sportler? Kraft, Leistung und Energie im Muskel

11.2 \pm 4.1