Related Experiment Video
Updated: Aug 12, 2025
07:03
Author Spotlight: Bridging the Gap Between In Vivo and Ex Vivo Studies with the "Avatar" Technique to Advance Muscle Mechanics Research
Published on: August 18, 2023
861
Numerical instability of Hill-type muscle models.
Sang-Hoon Yeo1, Jasper Verheul1,2, Walter Herzog3
1School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK.
Journal of the Royal Society, Interface
|February 1, 2023
Summary
Hill-type muscle models, widely used in simulations, can suffer from numerical instability. This study discusses their theoretical limitations and practical computational problems in biomechanics and animation.
Area of Science:
- Biomechanics
- Computational Biology
- Computer Animation
Background:
- Hill-type muscle models are computationally efficient for large-scale simulations.
- Despite their widespread use, their theoretical limitations are often overlooked.
Purpose of the Study:
- To discuss numerical instability issues in Hill-type muscle models.
- To highlight theoretical limitations and practical computational problems.
- To review current ad hoc solutions in biomechanics and animation.
Main Methods:
- Revisiting fundamental assumptions of Hill-type models.
- Conducting conceptual simulation studies to demonstrate instability.
- Reviewing existing literature on handling numerical issues.
Main Results:
- Hill-type models possess theoretical limitations in force-length and force-velocity relationships.
- Numerical instabilities can manifest as practical computational failures.
- Current methods for addressing these issues are largely ad hoc.
Conclusions:
- Numerical instability in Hill-type muscle models is a significant issue that requires attention.
- Further research is needed to develop robust methods for handling these instabilities.
- Improved models could enhance the reliability of musculoskeletal simulations and animations.
Related Concept Videos
01:29Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
92
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
92
01:20Motor Unit Stimulation
1.7K
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
1.7K
01:22Muscle Stimulation Frequency
2.4K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
2.4K
01:22Isotonic and Isometric Muscle Contractions
3.6K
Two primary types of muscle contractions are isotonic and isometric, each serving unique functions and involving distinct mechanisms. Both isotonic and isometric contractions are integral to the body's complex system of movement and stability. Isotonic exercises contribute significantly to functional strength and movement, while isometric contractions are crucial for maintaining posture and joint stability.
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
3.6K
01:14Design Example: Frog Muscle Response
280
A student is tasked to work on an intriguing experiment involving an RL (Resistor-Inductor) circuit to study the muscle response of a frog's leg to electrical stimulation. The RL circuit plays a crucial role in this experiment, providing the means to control and measure the electrical impulses that trigger muscle contraction.
When the switch connecting the RL circuit is closed, a brief muscle contraction is observed. This is because, at a steady state, the inductor acts like a short...
When the switch connecting the RL circuit is closed, a brief muscle contraction is observed. This is because, at a steady state, the inductor acts like a short...
280
01:15Muscle Contraction
91.3K
91.3K