Related Experiment Video
Updated: May 25, 2026
08:12
Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
Dynamic margins of stability during human walking in destabilizing environments
Patricia M McAndrew Young1, Jason M Wilken, Jonathan B Dingwell
1Department of Biomedical Engineering, University of Texas, Austin, TX 78712, USA.
Journal of Biomechanics
|February 14, 2012
Summary
Understanding dynamic walking stability is crucial for fall prevention. This study found that step-to-step changes in margins of stability (MOS) better reveal how individuals adapt to walking perturbations than average MOS.
Area of Science:
- Biomechanics
- Human locomotion
- Gait analysis
Background:
- Maintaining dynamic walking stability is essential for preventing falls, especially when facing external disturbances.
- Previous research has focused on average measures of stability, but dynamic, step-to-step control mechanisms remain less understood.
Purpose of the Study:
- To quantify the effects of continuous anterior-posterior (AP) and mediolateral (ML) oscillations on dynamic walking stability control.
- To investigate whether step-to-step changes in margins of stability (MOS) provide a more sensitive measure of stability control during perturbations than mean MOS.
Main Methods:
- Twelve subjects walked in a controlled environment (CAREN system) under five conditions: no perturbation, AP platform/visual oscillations, and ML platform/visual oscillations.
- Calculated anterior-posterior (AP) and mediolateral (ML) margins of stability (MOS) for each step.
- Utilized first-return plots to analyze step-to-step dynamics of MOS.
Main Results:
- Mediolateral MOS (MOS(ml)) was slightly larger during all perturbations compared to no perturbation.
- Anterior-posterior MOS (MOS(ap)) was significantly smaller during AP and ML oscillations.
- Variability of both MOS(ap) and MOS(ml) increased significantly under ML perturbations.
- Step-to-step MOS(ml) dynamics changed significantly across conditions, suggesting adaptive control strategies.
Conclusions:
- Continuous AP and ML oscillations alter dynamic walking stability control.
- Step-to-step analysis of margins of stability reveals more about adaptive control strategies during perturbations than mean MOS.
- This approach may offer a more sensitive method for assessing walking stability and fall risk.
More Related Videos
08:24Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb
Published on: August 30, 2016
07:52Evaluating Postural Control and Lower-extremity Muscle Activation in Individuals with Chronic Ankle Instability
Published on: September 18, 2020
Related Concept Videos
02:17Microtubule Instability
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated assembly and...
01:14Stability of structures
In mechanical engineering, the stability of systems under various forces is critical for designing durable and efficient structures. One fundamental way to explore these concepts is by analyzing systems like two rods connected at a pivot point, O, with a torsional spring of spring constant k at the pivot point. This system is similar in appearance to a scissor jack used to change tires on a car. In this case, the arms of the linkage (equivalent to the rods in this system) are entirely vertical,...
01:24Pole and System Stability
The transfer function is a fundamental concept representing the ratio of two polynomials. The numerator and denominator encapsulate the system's dynamics. The zeros and poles of this transfer function are critical in determining the system's behavior and stability.
Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's response.
Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's response.
01:23Stability of Equilibrium Configuration
Understanding the stability of equilibrium configurations is a fundamental part of mechanical engineering. In any system, there are three distinct types of equilibrium: stable, neutral, and unstable.
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
01:28Stability
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...
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...