Operator Bias Errors Are Reduced Using Standing Marker Alignment Device for Repeated Visit Studies

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Laura Hutchinson ◽  
Joel B. Schwartz ◽  
Amy M. Morton ◽  
Irene S. Davis ◽  
Kevin J. Deluzio ◽  
...  
Keyword(s):  
Knee Kinematics ◽  
Correlation Coefficients ◽  
Anatomical Landmarks ◽  
Coordinate Systems ◽  
Gait Kinematics ◽  
Ankle Kinematics ◽  
Out Of Plane ◽  
Optical Motion ◽  
Optical Motion Capture ◽  
Repeat Visits

When optical motion capture is used for motion analysis, reflective markers or a digitizer are typically used to record the location of anatomical landmarks identified through palpation. The landmarks are then used to construct anatomical coordinate systems. Failure to consistently identify landmarks through palpation over repeat tests creates artifacts in the kinematic waveforms. The purpose of this work was to improve intra- and inter-rater reliability in determining lower limb anatomical landmarks and the associated anatomical coordinate systems using a marker alignment device (MAD). The device aids the subject in recreating the same standing posture over multiple tests, and recreates the anatomical landmarks from previous static calibration trials. We tested three different raters who identified landmarks on eleven subjects. The subjects performed walking trials and their gait kinematics were analyzed with and without the device. Ankle kinematics were not improved by the device suggesting manual palpation over repeat visits is just as effective as the MAD. Intra-class correlation coefficients between gait kinematics registered to the reference static trial and registered to follow-up static trials with and without the device were improved between 1% and 33% when the device was used. Importantly, out-of-plane hip and knee kinematics showed the greatest improvements in repeatability. These results suggest that the device is well suited to reducing palpation artifact during repeat visits to the gait lab.

scholarly journals IMU gyroscopes are a valid alternative to 3D optical motion capture system for angular kinematics analysis in tennis

2020 ◽  
pp. 175433712096544 ◽  
Author(s):  
Gabriel Delgado-García ◽  
Jos Vanrenterghem ◽  
Emilio J Ruiz-Malagón ◽  
Pablo Molina-García ◽  
Javier Courel-Ibáñez ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Motion Capture ◽  
Correlation Coefficients ◽  
Strong Relationship ◽  
System Level ◽  
Optical Motion ◽  
Measurement Units ◽  
The Difference ◽  
Optical Motion Capture ◽  
Level Of Agreement

Whereas 3D optical motion capture (OMC) systems are considered the gold standard for kinematic assessment in sport science, they present some drawbacks that limit its use in the field. Inertial measurement units (IMUs) incorporating gyroscopes have been considered as a more practical alternative. Thus, the aim of the study was to evaluate the level of agreement for angular velocity between IMU gyroscopes and an OMC system for varying tennis strokes and intensities. In total, 240 signals of angular velocity from different body segments and types of strokes (forehand, backhand and service) were recorded from four players (two competition players and two beginners). The angular velocity of the IMU gyroscopes was compared to the angular velocity from the OMC system. Level of agreement was evaluated by correlation coefficients, magnitudes of errors in absolute and relative values and Bland-Altman plots. Differences between both systems were highly consistent within players’ skill (i.e. along the broad range of velocities) and axes ( x, y, z). Correlations ranged from 0.951 to 0.993, indicating a very strong relationship and concordance. The magnitude of the differences ranged from 4.4 to 35.4 deg·s−1. The difference relative to the maximum angular velocity achieved was less than 5.0%. The study concluded that IMUs and OMC systems showed comparable values. Thus, IMUs seem to be a valid alternative to detect meaningful differences in angular velocity during tennis groundstrokes in field-based experimentation.

Repeatability of Establishing Anatomical Coordinate Systems and the Initial Configuration of the Knee

2004 ◽  
Author(s):  
Stephanie J. Bechtold ◽  
Shon P. Darcy ◽  
Savio L.-Y. Woo ◽  
Richard E. Debski
Keyword(s):  
Degrees Of Freedom ◽  
Knee Kinematics ◽  
Joint Kinematics ◽  
Initial Configuration ◽  
Anatomical Landmarks ◽  
Coordinate Systems ◽  
Joint Injury ◽  
Six Degrees Of Freedom ◽  
Rehabilitation Protocols ◽  
Knee Joint Kinematics

Knee joint kinematics are a useful tool for diagnosing joint injury, assessing the effect of surgical procedures, and prescribing the correct rehabilitation protocols. Joint kinematics are measured using coordinate systems defined by anatomical landmarks. A change in location or orientation of these anatomical coordinate systems has been shown to affect the initial knee configuration and knee kinematics in all six degrees-of-freedom (DOF)[1–4]. Several methods have been utilized by researchers, but no universal methodology for determining the location and orientation of the anatomical coordinate systems has been established. The specific aim of this study was to compare the inter-observer repeatability of two methodologies for establishing anatomical coordinate systems and the initial configuration of the knee. The intra-observer repeatability of both methods was also determined to evaluate the effect of training level on establishing the anatomical coordinate systems.

scholarly journals Comparison of modelling and tracking methods for analysing elbow and forearm kinematics

2019 ◽  
Vol 233 (11) ◽  
pp. 1113-1121 ◽  
Author(s):  
Wei Wang ◽  
Dongmei Wang ◽  
Mariska Wesseling ◽  
Bin Xue ◽  
Feiyue Li
Keyword(s):  
Three Dimensional ◽  
Optimal Estimation ◽  
Elbow Flexion ◽  
Coordinate Systems ◽  
Kinematic Data ◽  
Measurement Protocol ◽  
Flexion Extension ◽  
Good Consistency ◽  
Optical Motion ◽  
Optical Motion Capture

This study aimed to find an optimal measurement protocol of elbow and forearm kinematics using different modelling and tracking methods. Kinematic data of elbow flexion/extension and forearm pronation/supination was acquired using optical motion capture from 12 healthy male volunteers. Segment coordinate systems for humerus, forearm, radius, ulna, and hand were defined. Different tracking methods, using anatomical markers or rigid or point maker clusters, were used to compute the three-dimensional rotations. Marker placement errors were assessed to evaluate the rigid body assumption. Multiple comparisons demonstrated statistical differences between tracking methods: compared to using only anatomical markers, tracking using clusters reduced the estimated range of pronation/supination by 14.9%–43.2%, while it estimated increased flexion/extension by 5.3%–9.1%. The study suggests using only anatomical markers exerts the optimal estimation of elbow and forearm kinematics. Modelling using the coordinate systems of the humerus and forearm and of the humerus and ulna, respectively, demonstrated good consistency with literature and are correspondingly regarded as the most appropriate approach for measuring pronation/supination and flexion/extension. The results are valuable in establishing a measurement protocol for analysing elbow and forearm kinematics, avoiding confusions and misinterpretations in communicating results from different methodologies.

scholarly journals Use of the Azure Kinect to measure foot clearance during obstacle crossing

2021 ◽  
Author(s):  
Kohei Yoshimoto ◽  
Masahiro Shinya
Keyword(s):  
Motion Capture ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Random Errors ◽  
Obstacle Crossing ◽  
Risk Of Falls ◽  
Optical Motion ◽  
Foot Clearance ◽  
Optical Motion Capture ◽  
Motion Capture Systems

Obstacle crossing is a typical adaptive locomotion known to be related to the risk of falls. Previous conventional studies have used elaborate and costly optical motion capture systems, which not only represent a considerable expense but also require participants to visit a laboratory. To overcome these shortcomings, we aimed to develop a practical and inexpensive solution for measuring obstacle-crossing behavior by using the Microsoft Azure Kinect, one of the most promising markerless motion capture systems. We validated the Azure Kinect as a tool to measure foot clearance and compared its performance to that of an optical motion capture system (Qualisys). We also determined the effect of the Kinect sensor placement on measurement performance. Sixteen healthy young men crossed obstacles of different heights (50, 150, and 250 mm). Kinect sensors were placed in front of and beside the obstacle as well as diagonally between those positions. As indices of measurement quality, we counted the number of measurement failures and calculated the systematic and random errors between the foot clearance measured by the Kinect and Qualisys. We also calculated the Pearson correlation coefficients between the Kinect and Qualisys measurements. The number of measurement failures and the systematic and random error were minimized when the Kinect was placed diagonally in front of the obstacle on the same side as the trail limb. The high correlation coefficient (r > 0.890) observed between the Kinect and Qualisys measurements suggests that the Azure Kinect has excellent potential for measuring foot clearance during obstacle-crossing tasks.

scholarly journals A Direct Comparison of Biplanar Videoradiography and Optical Motion Capture for Foot and Ankle Kinematics

2019 ◽  
Vol 7 ◽  
Author(s):  
Sarah E. Kessler ◽  
Michael J. Rainbow ◽  
Glen A. Lichtwark ◽  
Andrew G. Cresswell ◽  
Susan E. D'Andrea ◽  
...  
Keyword(s):  
Motion Capture ◽  
Foot And Ankle ◽  
Ankle Kinematics ◽  
Optical Motion ◽  
Optical Motion Capture

scholarly journals Comparison of Gait Analysis Between a Triaxial Accelerometer-Based Device and an Optical Motion Capture System

2020 ◽  
Author(s):  
Taisuke Ito ◽  
Yuichi Ota
Keyword(s):  
Gait Analysis ◽  
Motion Capture ◽  
Measurement Accuracy ◽  
Reaction Force ◽  
Correlation Coefficients ◽  
P Value ◽  
Motion Capture System ◽  
Optical Motion ◽  
Optical Motion Capture ◽  
Good Agreement

AYUMI EYE is an accelerometer-based gait analysis device that measures the 3D accelerations of the human trunk. This study investigated the measurement accuracy of the AYUMI EYE as hardware as well as the accuracy of the gait cycle extraction program via simultaneous measurements using AYUMI EYE, a ground reaction force (GRF), and an optical motion capture system called VICON. The study was conducted with four healthy individuals as participants. The gait data were obtained by simulating four different patterns for three trials each: normal walking, anterior-tilt walking, hemiplegic walking, and shuffling walking. The AYUMI EYE and VICON showed good agreement for both the acceleration and displacement data. The durations of subsequent stride cycles calculated using the AYUMI EYE and GRF were in good agreement based on the calculated cross-correlation coefficients (CCs) with an r value of 0.896 and p-value less than 0.05, and their accuracies for these results were sufficient.

scholarly journals Association between the On-Plane Angular Motions of the Axle-Chain System and Clubhead Speed in Skilled Male Golfers

2020 ◽  
Vol 10 (17) ◽  
pp. 5728
Author(s):  
Morgan V. Madrid ◽  
Marco A. Avalos ◽  
Nicholas A. Levine ◽  
Noelle J. Tuttle ◽  
Kevin A. Becker ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Angular Position ◽  
Correlation Coefficients ◽  
Comprehensive Investigation ◽  
Chain System ◽  
Performance Factors ◽  
Optical Motion ◽  
Motion Characteristics ◽  
Optical Motion Capture ◽  
Shoulder Separation

The on-plane rotations of the inclined axle-chain system on the functional swing plane (FSP) can represent the angular motions of the golfer–club system closely. The purpose of this study was to identify key performance factors in golf through a comprehensive investigation of the association between the angular motion characteristics of the axle-chain system and clubhead speed in skilled golfers. Sixty-six male golfers (handicap ≤ 3) performed full-effort shots in three club conditions: driver, 5-iron, and pitching wedge. Swing trials were captured with an optical motion capture system, and the hip/shoulder lines, upper lever, club, and wrist angular positions/velocities were calculated. Time, angular position, range of rotation, and peak angular velocity parameters were extracted and their correlation coefficients (Pearson and Spearman) to actual and normalized clubhead speeds were computed (p < 0.05). Higher clubhead speed was associated with shorter downswing phases, larger rotation ranges (hip/shoulder lines, and upper lever), larger hip–shoulder separation at impact, delayed transitions (hip line and upper lever), faster rotations (backswing, downswing, and impact), and larger angular velocity losses (hip line and upper lever) with additional club- and body-specific correlations. Clubhead speed was not well associated with wrist cock angles/ranges, X-factors/stretches, and timings of the downswing peak.

Quantifying spinal gait kinematics using an enhanced optical motion capture approach in adolescent idiopathic scoliosis

2016 ◽  
Vol 44 ◽  
pp. 231-237 ◽  
Author(s):  
Stefan Schmid ◽  
Daniel Studer ◽  
Carol-Claudius Hasler ◽  
Jacqueline Romkes ◽  
William R. Taylor ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Motion Capture ◽  
Gait Kinematics ◽  
Optical Motion ◽  
Optical Motion Capture
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