Benchmarking the Accuracy of Inertial Measurement Units for Estimating Joint Reactions

2013 ◽  
Author(s):  
Ryan S. McGinnis ◽  
Jessandra Hough ◽  
N. C. Perkins
Keyword(s):  
Three Dimensional ◽  
Correlation Coefficients ◽  
Human Motion ◽  
Load Cell ◽  
Great Promise ◽  
Human Motion Analysis ◽  
Double Pendulum ◽  
Inertial Measurement Units ◽  
Inertial Measurement ◽  
Measurement Units

Newly developed miniature wireless inertial measurement units (IMUs) hold great promise for measuring and analyzing multibody system dynamics. This relatively inexpensive technology enables non-invasive motion tracking in broad applications, including human motion analysis. The second part of this two-part paper advances the use of an array of IMUs to estimate the joint reactions (forces and moments) in multibody systems via inverse dynamic modeling. In particular, this paper reports a benchmark experiment on a double-pendulum that reveals the accuracy of IMU-informed estimates of joint reactions. The estimated reactions are compared to those measured by high precision miniature (6 dof) load cells. Results from ten trials demonstrate that IMU-informed estimates of the three dimensional reaction forces remain within 5.0% RMS of the load cell measurements and with correlation coefficients greater than 0.95 on average. Similarly, the IMU-informed estimates of the three dimensional reaction moments remain within 5.9% RMS of the load cell measurements and with correlation coefficients greater than 0.88 on average. The sensitivity of these estimates to mass center location is discussed. Looking ahead, this benchmarking study supports the promising and broad use of this technology for estimating joint reactions in human motion applications.

Accuracy of Wearable Sensors for Estimating Joint Reactions

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
Ryan S. McGinnis ◽  
Jessandra Hough ◽  
Noel C. Perkins
Keyword(s):  
Degrees Of Freedom ◽  
Wearable Sensors ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Human Motion ◽  
Load Cell ◽  
Great Promise ◽  
Human Motion Analysis ◽  
Double Pendulum ◽  
Inverse Dynamic

Miniature wireless inertial measurement units (IMUs) hold great promise for measuring and analyzing multibody system dynamics. This relatively inexpensive technology enables noninvasive motion tracking in broad applications, including human motion analysis. This paper advances the use of an array of IMUs to estimate the joint reactions (forces and moments) in multibody systems via inverse dynamic modeling. In particular, this paper reports a benchmark experiment on a double-pendulum that reveals the accuracy of IMU-informed estimates of joint reactions. The estimated reactions are compared to those measured by high-precision miniature (6 degrees-of-freedom) load cells. Results from ten trials demonstrate that IMU-informed estimates of the three-dimensional reaction forces remain within 5.0% RMS of the load cell measurements and with correlation coefficients greater than 0.95 on average. Similarly, the IMU-informed estimates of the three-dimensional reaction moments remain within 5.9% RMS of the load cell measurements and with correlation coefficients greater than 0.88 on average. The sensitivity of these estimates to mass center location is discussed. Looking ahead, this benchmarking study supports the promising and broad use of this technology for estimating joint reactions in human motion applications.

Benchmarking the Accuracy of Inertial Measurement Units for Estimating Kinetic Energy

2013 ◽  
Author(s):  
Jessandra Hough ◽  
Ryan S. McGinnis ◽  
N. C. Perkins
Keyword(s):  
Kinetic Energy ◽  
Health And Safety ◽  
Human Motion ◽  
Double Pendulum ◽  
Inertial Measurement Units ◽  
Inertial Measurement ◽  
System A ◽  
Time Estimates ◽  
Worker Health And Safety ◽  
Measurement Units

The energetics of human motion has been intensely studied using experimental and theoretical methods. Knowing the kinetic energy of the human body, and its decomposition into the kinetic energies of the major body segments, has tremendous value in applications ranging from physical therapy, athlete training, soldier performance, worker health and safety, among other uses. Significant challenges thwart our ability to measure segmental kinetic energy in real (non-laboratory) environments such as in the home or workplace, or on the playing/training field. The aim of this research is to address these challenges by advancing the use of an array of miniaturized body-worn inertial measurement units (IMUs) for estimating segmental kinetic energy. As a step towards this goal, this study reports a benchmark experiment that demonstrates the accuracy of IMU-derived estimates of segmental kinetic energy. The study is conducted on a well-characterized mechanical system, a double pendulum that also serves as an apt model for the lower or upper extremities. A two-node IMU array is used to measure the kinematics of each segment as input to the segmental kinetic energy computations. The segments are also instrumented with two high-precision optical encoders that provide the truth data for kinetic energy. The segmental kinetic energies estimated using the IMU array remain within 3.5% and 3.9% of the kinetic energies measured by the optical encoders for the top and bottom segments, respectively, for the freely decaying pendulum oscillations considered. These promising results support the future development of body-worn IMU arrays for real-time estimates of segmental kinetic energy for health, sports and military applications.

scholarly journals Validity of Wearable Sensors at the Shoulder Joint: Combining Wireless Electromyography Sensors and Inertial Measurement Units to Perform Physical Workplace Assessments

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1885 ◽  
Author(s):  
Isabelle Poitras ◽  
Mathieu Bielmann ◽  
Alexandre Campeau-Lecours ◽  
Catherine Mercier ◽  
Laurent J. Bouyer ◽  
...  
Keyword(s):  
Wearable Sensors ◽  
Correlation Coefficients ◽  
Emg Activity ◽  
Complex Task ◽  
Inertial Measurement Units ◽  
Simple Task ◽  
Inertial Measurement ◽  
Work Related ◽  
Measurement Units ◽  
Shoulder Kinematics

Background: Workplace adaptation is the preferred method of intervention to diminish risk factors associated with the development of work-related shoulder disorders. However, the majority of the workplace assessments performed are subjective (e.g., questionnaires). Quantitative assessments are required to support workplace adaptations. The aims of this study are to assess the concurrent validity of inertial measurement units (IMUs; MVN, Xsens) in comparison to a motion capture system (Vicon) during lifting tasks, and establish the discriminative validity of a wireless electromyography (EMG) system for the evaluation of muscle activity. Methods: Sixteen participants performed 12 simple tasks (shoulder flexion, abduction, scaption) and 16 complex lifting tasks (lifting crates of different weights at different heights). A Delsys Trigno EMG system was used to record anterior and middle deltoids’ EMG activity, while the Xsens and Vicon simultaneously recorded shoulder kinematics. Results: For IMUs, correlation coefficients were high (simple task: >0.968; complex task: >0.84) and RMSEs were low (simple task: <6.72°; complex task: <11.5°). For EMG, a significant effect of weight, height and a weight x height interaction (anterior: p < 0.001; middle: p < 0.03) were observed for RMS EMG activity. Conclusions: These results suggest that wireless EMG and IMUs are valid units that can be used to measure physical demand in workplace assessments.

Development of a Wearable Scoliosis Monitoring System Using Inertial Sensors

2015 ◽  
Vol 811 ◽  
pp. 353-358
Author(s):  
Gheorghe Daniel Voinea ◽  
Gheorghe Mogan
Keyword(s):  
Monitoring System ◽  
Inertial Sensors ◽  
Human Motion ◽  
Roll Angle ◽  
Complex Task ◽  
Lateral Movement ◽  
Inertial Measurement Units ◽  
Inertial Measurement ◽  
Spinal Disorder ◽  
Measurement Units

Monitoring human motion with magnetic and inertial measurement units is a complex task and there are many factors that must be taken into consideration. In this work, a wearable system for monitoring scoliosis using three inertial measurement units (IMUs) is introduced. The proposed solution can be used indoor and is focused on using the roll angle for measuring lateral movement of the spine, which characterizes the scoliosis spinal disorder.

scholarly journals Fusing Accelerometry with Videography to Monitor the Effect of Fatigue on Punching Performance in Elite Boxers

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5749
Author(s):  
Nicos Haralabidis ◽  
David John Saxby ◽  
Claudio Pizzolato ◽  
Laurie Needham ◽  
Dario Cazzola ◽  
...  
Keyword(s):  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Statistical Parametric Mapping ◽  
Shoulder Abduction ◽  
Inertial Measurement Units ◽  
Inertial Measurement ◽  
Fatigue Protocol ◽  
Custom Made ◽  
Measurement Units

Wearable sensors and motion capture technology are accepted instruments to measure spatiotemporal variables during punching performance and to study the externally observable effects of fatigue. This study aimed to develop a computational framework enabling three-dimensional inverse dynamics analysis through the tracking of punching kinematics obtained from inertial measurement units and uniplanar videography. The framework was applied to six elite male boxers performing a boxing-specific punch fatigue protocol. OpenPose was used to label left side upper-limb landmarks from which sagittal plane kinematics were computed. Custom-made inertial measurement units were embedded into the boxing gloves, and three-dimensional punch accelerations were analyzed using statistical parametric mapping to evaluate the effects of both fatigue and laterality. Tracking simulations of a sub-set of left-handed punches were formulated as optimal control problems and converted to nonlinear programming problems for solution with a trapezoid collocation method. The laterality analysis revealed the dominant side fatigued more than the non-dominant, while tracking simulations revealed shoulder abduction and elevation moments increased across the fatigue protocol. In future, such advanced simulation and analysis could be performed in ecologically valid contexts, whereby multiple inertial measurement units and video cameras might be used to model a more complete set of dynamics.

Sign in / Sign up

Export Citation Format

Share Document