Related Experiment Video
Updated: May 18, 2026
08:51
Data Acquisition and Analysis In Brainstem Evoked Response Audiometry In Mice
Published on: May 10, 2019
Analysis of damped tissue vibrations in time-frequency space: a wavelet-based approach
Hendrik Enders1, Vinzenz von Tscharner, Benno M Nigg
1Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada. henders@kin.ucalgary.ca
Journal of Biomechanics
|September 22, 2012
Summary
This study introduces a new wavelet-based method to measure soft tissue vibration damping during running. The novel approach accurately quantifies damping differences between surfaces, unlike traditional single oscillation models.
Area of Science:
- Biomechanics
- Vibration Analysis
- Human Locomotion
Background:
- Vibrations in soft tissues during locomotion are complex and not accurately modeled by single sinusoidal oscillations.
- Existing methods struggle to quantify damping in dynamic movements like sprinting.
Purpose of the Study:
- To introduce and validate a novel wavelet-based time-frequency method for quantifying soft tissue vibration damping.
- To analyze differences in damping characteristics on hard versus soft surfaces during sprinting.
Main Methods:
- A wavelet-based time-frequency approach was developed to analyze superimposed oscillations.
- Eight healthy subjects performed sprinting trials on hard and soft surfaces.
- Vibrations of the medial gastrocnemius muscle's overlying soft tissue were measured.
Main Results:
- The wavelet method determined damping coefficients with an average error of 2.2%.
- Significant differences in soft tissue damping were detected between the hard and soft surfaces.
- The hard surface showed a lower damping coefficient (7.02 s⁻¹) compared to the soft surface (p<0.05).
Conclusions:
- The developed wavelet-based method accurately quantifies vibration damping in complex systems with multiple interfering modes.
- This time-frequency analysis is more suitable for analyzing non-sinusoidal acceleration traces in human locomotion.
- The findings highlight surface-dependent differences in soft tissue damping during sprinting.
Related Concept Videos
01:15Discrete Fourier Transform
The Discrete Fourier Transform (DFT) is a fundamental tool in signal processing, extending the discrete-time Fourier transform by evaluating discrete signals at uniformly spaced frequency intervals. This transformation converts a finite sequence of time-domain samples into frequency components, each representing complex sinusoids ordered by frequency. The DFT translates these sequences into the frequency domain, effectively indicating the magnitude and phase of each frequency component present...
01:20Types of Damping
If the amount of damping in a system is gradually increased, the period and frequency start to become affected because damping opposes, and hence slows, the back and forth motion (the net force is smaller in both directions). If there is a very large amount of damping, the system does not even oscillate; instead, it slowly moves toward equilibrium. In brief, an overdamped system moves slowly towards equilibrium, whereas an underdamped system moves quickly to equilibrium but will oscillate about...
01:07Damped Oscillations
In the real world, oscillations seldom follow true simple harmonic motion. A system that continues its motion indefinitely without losing its amplitude is termed undamped. However, friction of some sort usually dampens the motion, so it fades away or needs more force to continue. For example, a guitar string stops oscillating a few seconds after being plucked. Similarly, one must continually push a swing to keep a child swinging on a playground.
Although friction and other non-conservative...
Although friction and other non-conservative...
01:01Sound Waves
Sound waves can be thought of as fluctuations in the pressure of a medium through which they propagate. Since the pressure also makes the medium's particles vibrate along its direction of motion, the waves can be modeled as the displacement of the medium's particles from their mean position.
Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,...
Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,...
01:07Effective Value of a Periodic Waveform
The concept of effective value, the root mean square (RMS) value, is crucial in understanding electrical circuits and power delivery. This idea emerges from the necessity to measure the effectiveness of a voltage or current source in supplying power to a resistive load.
The effective value of a periodic current represents the direct current (DC) that conveys the same average power to a resistor as the periodic current itself. This concept is crucial when assessing AC circuits. To determine the...
The effective value of a periodic current represents the direct current (DC) that conveys the same average power to a resistor as the periodic current itself. This concept is crucial when assessing AC circuits. To determine the...
01:20Discrete-Time Fourier Series
The Discrete-Time Fourier Series (DTFS) is a fundamental concept in signal processing, serving as the discrete-time counterpart to the continuous-time Fourier series. It allows for the representation and analysis of discrete-time periodic signals in terms of their frequency components. Unlike its continuous counterpart, which utilizes integrals, the calculation of DTFS expansion coefficients involves summations due to the discrete nature of the signal.
For a discrete-time periodic signal x[n]...
For a discrete-time periodic signal x[n]...