Dynamic Analysis of Human Gait Disorder and Metabolical Cost Estimation

Ackermann, Marko; Schiehlen, Werner

doi:10.1007/s00419-006-0027-7

Cited by 37 publications

(29 citation statements)

References 43 publications

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“…In most skeleton joint structures, the number of muscles exceeds the degrees of freedom. An optimisation procedure can be useful to solve this redundancy problem with respect to a physiologically motivated cost function, which could be, for example, the metabolic effort of the motion (Umberger et al 2003;Ackermann and Schiehlen 2006) or a criterion of maximum endurance of musculoskeletal function (Crowninshield and Brand 1981).…”

Section: Introductionmentioning

confidence: 99%

On the relevance of structure preservation to simulations of muscle actuated movements

Maas

Siebert

Leyendecker

2011

Biomech Model Mechanobiol

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In this work, we implement a typical nonlinear Hill-type muscle model in a structure-preserving simulation framework and investigate the differences to standard simulations of muscle-actuated movements with MATLAB/Simulink. The latter is a common tool to solve dynamical problems, in particular, in biomechanic investigations. Despite the simplicity of the examples used for comparison, it becomes obvious that the MATLAB/Simulink integrators artificially loose or gain energy and angular momentum during dynamic simulations. The relative energy error of the MATLAB/Simulink integrators related to a very low actual muscle work can naturally reach large values, even higher than 100%. But also during periods with large muscle work, the relative energy error reaches up to 2%. Even in simulations with very small time steps, energy and angular momentum errors are still present using MATLAB/Simulink and can (at least partially) be responsible for phase errors in long-term simulations. This typical behaviour of commercial integrators is known to increase for more complex models or for computations with larger time steps, whose use is crucial for efficiency, especially in the context of optimal control simulations. In contrast to that, time-stepping schemes being derived from a discrete variational principle yield discrete analogues of the Euler-Lagrange equations and Noethers theorem. This ensures that the structure of the system is preserved, i.e. the simulation results are symplectic and momentum consistent and exhibit a good energy behaviour (no drift).

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Section: Introductionmentioning

confidence: 99%

On the relevance of structure preservation to simulations of muscle actuated movements

Maas

Siebert

Leyendecker

2011

Biomech Model Mechanobiol

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“…Multibody system dynamics (MSD) techniques are potentially very powerful in this field, and there are many contributions from the MSD community to this challenging problem [3,4,18,20]. The human body can be assumed to be a multibody system actuated by muscles.…”

Section: Introductionmentioning

confidence: 99%

3D-Simulation of human walking by parameter optimization

García-Vallejo

Schiehlen

2011

Arch Appl Mech

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The simulation of human gait is a complex dynamical problem that requires accounting for energy consumption as well as dealing with a redundantly actuated multibody system. If muscle forces and generalized coordinates are parameterized, optimization techniques allow the simulation of the muscle forces and of the walking motion. An optimization framework is presented for non-symmetrical gait cycles found in the presence of one-sided gait disorders. The motion of each leg is independently parameterized for a whole walking cycle. The non-linear constraints used to fulfill the equations of motion and the kinematical constraints of the different walking phases are implemented in an efficient way. Fifth-order splines are used for the parameterization to reduce the oscillatory behavior coming from non-periodicity conditions. To achieve the computational performance required for three-dimensional simulations, the spline interpolation problem has been split in two parts, one is performed in a preprocessing stage and the other during the optimization. Numerical differentiation via finite differences is avoided by implementing analytical derivatives of the splines functions and of the contractile element force law. The results show good numerical performance, and the computational efficiency for 3D-simulations with one-sided gait disorders is highlighted.

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“…1d) combines the passive properties of the Kelvin model with the active properties given by the contractile element (CE). Nowadays, the Hill-type muscle model is the most used in biomechanical studies involving muscular coordination (Zajac, 1989;Van Soest and Bobbert, 1993;Van Den Bogert et al, 1998;Thelen, 2003;Silva, 2003;Ackermann and Schiehlen, 2006;Ackermann, 2007;García-Vallejo, 2010;Alonso et al, 2012). Figure 1e shows an schematic representation of the muscle-tendon unit using the Hill-type muscle model.…”

Section: Introductionmentioning

confidence: 99%

A comparison among different Hill-type contraction dynamics formulations for muscle force estimation

Romero

Sánchez

2016

Mech. Sci.

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Abstract.Muscle is a type of tissue able to contract and, thus, shorten, producing a pulling force able to generate movement. The analysis of its activity is essential to understand how the force is generated to perform a movement and how that force can be estimated from direct or indirect measurements. Hill-type muscle model is one of the most used models to describe the mechanism of force production. It is composed by different elements that describe the behaviour of the muscle (contractile, series elastic and parallel elastic element) and tendon. In this work we analyze the differences between different formulations found in the literature for these elements. To evaluate the differences, a flexo-extension movement of the arm was performed, using as input to the different models the surface electromyography signal recorded and the muscle-tendon lengths and contraction velocities obtained by means of inverse dynamic analysis. The results show that the force predicted by the different models is similar and the main differences in muscle force prediction were observed at full-flexion. The results are expected to contribute in the selection of the different formulations of Hill-type muscle model to solve a specific problem.

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Dynamic Analysis of Human Gait Disorder and Metabolical Cost Estimation

Cited by 37 publications

References 43 publications

On the relevance of structure preservation to simulations of muscle actuated movements

On the relevance of structure preservation to simulations of muscle actuated movements

3D-Simulation of human walking by parameter optimization

A comparison among different Hill-type contraction dynamics formulations for muscle force estimation

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