Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Stability01:28

Stability

The time response of a linear time-invariant (LTI) system can be divided into transient and steady-state responses. The transient response represents the system's initial reaction to a change in input and diminishes to zero over time. In contrast, the steady-state response is the behavior that persists after the transient effects have faded.
The stability of an LTI system is determined by the roots of its characteristic equation, known as poles. A system is stable if it produces a bounded...
Rigid Body Equilibrium Problems - I00:49

Rigid Body Equilibrium Problems - I

A rigid body is said to be in static equilibrium when the net force and the net torque acting on the system is equal to zero. To solve for rigid body equilibrium problems, do the following steps.
Rigid Body Equilibrium Problems - II01:21

Rigid Body Equilibrium Problems - II

A rigid body is in static equilibrium when the net force and the net torque acting on the system are equal to zero.
Consider two children sitting on a seesaw, which has negligible mass. The first child has a mass (m1) of 26 kg and sits at point A, which is 1.6 meters (r1) from the pivot point B; the second child has a mass (m2) of 32 kg and sits at point C. How far from the pivot point B should the second child sit (r2) to balance the seesaw?
Stability of Equilibrium Configuration: Problem Solving01:13

Stability of Equilibrium Configuration: Problem Solving

The stability of equilibrium configurations is an important concept in physics, engineering, and other related fields. In simple terms, it refers to the tendency of an object or system to return to its equilibrium position after being disturbed. The stability of an equilibrium configuration can be analyzed by considering the potential energy function of the system and examining its behavior near the equilibrium point.
Problem-solving in the context of the stability of equilibrium configuration...
Normal and Tangetial Components: Problem Solving01:24

Normal and Tangetial Components: Problem Solving

Consider a man with a mass of 70 kg seated in a chair connected to a pin support through a member BC. If the man maintains an upright position, the task is to determine the horizontal and vertical reactions of the chair on the man when the member makes a 45° angle with the horizontal. At this moment, the man has a speed of 5 m/s, increasing at a rate of 1 m/s².
Multimachine Stability01:25

Multimachine Stability

Multimachine stability analysis is crucial for understanding the dynamics and stability of power systems with multiple synchronous machines. The objective is to solve the swing equations for a network of M machines connected to an N-bus power system.
In analyzing the system, the nodal equations represent the relationship between bus voltages, machine voltages, and machine currents. The nodal equation is given by:

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Evaluating Different Optimization Criteria for Estimating Spine Loads and Muscle Activity During Manual Lifting With and Without Assistance from Back-Support Exoskeletons.

Annals of biomedical engineering·2026
Same author

Vision-language models for occupational physical exposure assessment: Classification and temporal segmentation of manual material handling tasks.

Applied ergonomics·2026
Same author

Passive back- and arm-support exoskeletons have effects on physical demands and user perceptions in simulated manual mining tasks that are generally beneficial but are both device- and task-specific.

Applied ergonomics·2026
Same author

Evaluating model-estimated shoulder muscle activity during overhead work with varied task demands and exoskeleton use.

Applied ergonomics·2026
Same author

Feasibility of forecasting self-injurious behavior among autistic youth using wearable sensors and machine learning models.

Scientific reports·2026
Same author

Effectiveness and usability of a trunk posture feedback system: A longitudinal field study for up to six weeks in a distribution center.

Applied ergonomics·2026

Related Experiment Video

Updated: Jun 17, 2026

Experimental Methods to Study Human Postural Control
08:12

Experimental Methods to Study Human Postural Control

Published on: September 11, 2019

Mathematical modeling and simulation of seated stability.

Martin L Tanaka1, Shane D Ross, Maury A Nussbaum

  • 1Department of Orthopaedic Surgery, Wake Forest University, Winston-Salem, NC 27157, USA. mtanaka@wfubmc.edu

Journal of Biomechanics
|December 19, 2009
PubMed
Summary

This study models human torso stability on a wobble chair using finite time Lyapunov exponent (FTLE) fields. Findings reveal FTLE fields can map the boundaries of stability, aiding in understanding spinal injury risks.

More Related Videos

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
08:40

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Published on: November 11, 2022

A Vibrotactile Feedback Device for Seated Balance Assessment and Training
09:13

A Vibrotactile Feedback Device for Seated Balance Assessment and Training

Published on: January 20, 2019

Related Experiment Videos

Last Updated: Jun 17, 2026

Experimental Methods to Study Human Postural Control
08:12

Experimental Methods to Study Human Postural Control

Published on: September 11, 2019

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
08:40

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Published on: November 11, 2022

A Vibrotactile Feedback Device for Seated Balance Assessment and Training
09:13

A Vibrotactile Feedback Device for Seated Balance Assessment and Training

Published on: January 20, 2019

Area of Science:

  • Biomechanics
  • Dynamical Systems Theory

Background:

  • Existing methods quantify spinal stability within known stable regions.
  • The extent of the stable region itself remains largely unquantified.
  • Understanding stability boundaries is crucial for assessing risks like spinal injury.

Purpose of the Study:

  • To determine the extent of the stable region for human torso dynamics.
  • To develop a method for locating state space boundaries related to torso stability.
  • To establish a framework for assessing health risks associated with spinal injury and balance recovery.

Main Methods:

  • Developed a 2D mathematical model of a human on a wobble chair.
  • Utilized forward dynamic simulations to compute state trajectories.
  • Calculated a finite time Lyapunov exponent (FTLE) field to map trajectory divergence.
  • Identified ridges in the FTLE field as boundaries between stability and failure.

Main Results:

  • FTLE field ridges successfully demarcated regions of stability and instability (falling).
  • The basin of stability identified via FTLE closely matched an alternative method.
  • An equilibrium manifold was identified, acting as a low-dimensional attractor.

Conclusions:

  • FTLE field analysis is a viable method for locating state space boundaries of torso stability.
  • This approach can help assess factors contributing to spinal injury and poor balance.
  • The methodology is adaptable for finding state space boundaries in other biomechanical applications.