Summary Podium 1_1
Embedded Arts
Lise Worthen-Chaudhari
Departments of Physical Medicine and Rehabilitation and Dance
The Ohio State University
Columbus, OH, USA
While art, music and dance therapy are sometimes offered to patients as adjunctive therapy, few attempts have been made to embed the arts within rehabilitation programs despite preliminary evidence that such implementation improves clinical outcomes. More study is needed to explore the impact of artistic, improvisational and creative neural pathways activated during exercise on motor learning and rehabilitation outcomes. This work is important to the field of movement studies in that: 1) newly available generative, interactive arts technologies will enhance standard rehabilitation, 2) embedding creative process within rehabilitation exercises has the potential to improve outcomes, 3) outputting artistic work from rehabilitation exercises adds an economic element to rehabilitation endeavors, 4) motion capture data captured and represented as artistic output will be recorded for quantitative outcomes analysis and 5) the artistic nature of personal movement in a rehabilitation setting will be explored.
Summary Podium 1_2
Motion Capture for Experimental Animation
Vita Berezina-Blackburn
Advanced Computing Center for the Arts and Design (ACCAD)
The Ohio State University
Columbus, OH, USA
This report describes a series of approaches for using optical motion capture as a tool in experimental animation. Point data is imported into 3d software, which is used to create different types of visualizations, ranging from abstract to figurative, driven exclusively by motion data, and mixed with procedural or keyframe animation. Other uses of performance data include controlling camera movement, lighting and construction of 3d environment.
Summary Podium 1_3
Recognizing Emotion in Gait with Virtual Marker and Video Displays of the Body
Melissa Gross, Lan Wei, Josh D’Angelo, Andrea Bartoszewicz, and Irully Jeong
Department of Movement Science
School of Kinesiology
University of Michigan
Ann Arbor, Michigan, USA
Recognizing emotion in body movements is important for clinical, basic science and defense applications. Video displays have been used in emotion recognition studies, but virtual maker displays would enable simulation studies. The primary goal of this study was to identify display parameters important for recognizing emotion in gait, including display type (video or virtual markers), view perspective (side, front or oblique), display repetition (three or six loops), and spine model (2-4 virtual markers placed at different body locations). We found that emotion recognition was strongly affected by display type and view perspective, but was less influenced by display repetition and spine model. Together, these results indicate that virtual markers generated with biomechanical software can be used effectively in studies of emotion recognition from body movements, but that more work is needed to understand how to improve virtual marker displays so that emotion recognition rates approach those found with video displays.
Summary Podium 2_1
A filter method for the global optimization method
Philipp Huber
Human Performance Research
Graz Karl Franzens & Medical University Graz
Graz, Austria
Filtering is an important step in the analysis of motion capture data. A possible way to filter generalized coordinates of spherical joints computed from the global optimization approach is to determine the angular velocity. This is done using the matrix logarithm function on a transfer matrix between two time steps. A filter is applied on the angular velocities.
The main advantages are that one can thereby compute a filtered rotation matrix from which angles can be conveniently determined in any representation. Discontinuities in angle parameters are dealt with implicitly and due to the orhonormality of the basis each component of the angular velocity can be filtered separately with no cross talk.
Summary Podium 2_2
Missing contact forces estimation by minimizing net joint torques
Application to a sit-to-stand motion
Julien Causse, Thomas Robert, Gilles Monnier, Xuguang Wang
Université de Lyon, PSA Peugeot-Citroen, In-Motion
Lyon, France
A limitation in dynamic analysis of motion is that the measurement of all external contacts is needed to evaluate joint loads. The present study investigates the estimation of external contact forces when several contact measurements are missing. The paper presents a generalized pseudo inverse optimization method by minimizing net joint torques. The method and the criterion are experimentally assessed with sit-to-stand motions. The accuracy was evaluated by comparing the simulated with the experimental data at the level of joint torques and external contacts. The results, in terms of shape and magnitude, confirmed the feasibility of the approach to estimate external contact forces.
Summary Podium 2_3
Estimation of 3D Human Body Kinematics Using Marker Tracking
Jenchieh Lee, Henryk Flashner, Jill L. McNitt-Gray
Department of Aerospace and Mechanical Engineering
Departments of Kinesiology, Biomedical Engineering, Biological Sciences
University of Southern California
Los Angeles, CA
Accurate modeling of the musculoskeletal system during three-dimensional human movements is crucial for determining the torques required to generate the motion, for computing the loads on various parts of the body, and testing hypotheses regarding control logic of the nervous system. In this study, the problem of estimating the kinematics a system of n interconnected rigid bodies performing motion in three-dimensional space is formulated as a sequence of constrained optimizations problems. The proposed approach provides a means to reduce position measurement error so that system integrity is preserved and dynamic laws are satisfied. Interconnections between body segments during motion were preserved and the system center of mass kinematics and angular momentum satisfy conservation laws by formulating constraints included in the objective functions using a penalty function approach. Preserving these properties is important when validating dynamic multi-link models of human body motion used to test hypotheses regarding the control logic.
Summary Podium 3_1
Development and validation of a finger tracking technique using skin mounted markers
Warlow, O.M.E. & Lawson, S.E.M.
CREST, Bioengineering Research Group
School of Mechanical and Systems Engineering, Newcastle University
Newcastle Upon Tyne, United Kingdom
The internal forces transmitted through the finger can be calculated using biomechanical models and an accurate measurement of finger position is a necessary input to these. This study is on the development of a technique to track dynamic and highly loaded finger movement, when internal forces are likely to be greatest. Three 4mm hemispherical markers were attached in a non-collinear arrangement directly to each phalanx of the index finger and dorsal surface of the right hand (12 in total). A seven camera Vicon MX13+ motion capture system (VICON Ltd, U.K.) was used to track their position. For each finger joint, functional axes of rotation were calculated and used calculate the length of each phalanx. The principle factor considered as indicative of the accuracy of the method was a minimal standard deviation in the phalanx lengths. Through optimisation of the marker set this was reduced to an average of 0.54mm.
Summary Podium 3_2
3D Transmission of the Seated Human Performing Upper Limb Reaching Movements in Vehicle Operations
Heon-Jeong Kim and Bernard J. Martin
Department of Mechanical Engineering, University of Michigan
Department of Industrial and Operations Engineering, University of Michigan
Ann Arbor, Michigan, U.S.A
Reaching movements is the primary activity in manual operations in vehicle operations, and whole-body vibration commonly interferes with the performance of reaching movements. For the enhancement of operator’s safety and performance, vibration transmission to the seated operator is analyzed with consideration of the dynamic aspect of upper limb reaching movements. Compared to earlier studies quantifying one-dimensional vibration transmissibility of the seated human or analyzing reach kinematics in a static environment, the present work investigates three dimensional transmission propagated through body segments under sinusoidal vibration exposure during reaching movements. The analysis of vibration propagation through the torso and upper limb segments shows the influence of movement direction as well as vibration conditions. The results from this work may provide in-depth insight for improvement of vehicle design and man-machine interface design and adaptation of movement strategies to limit the influence of vibration.
Summary Podium 3_3
Upper and lower limb coordination in truck cabin accessibility
Comparison of kinematic and dynamic coordinations.
G. Monnier, E.Chateauroux, C. Roybin, X. Wang, T. Robert
Université de Lyon, In-Motion, Volvo 3P
France
As for industrial tasks such as truck cabin accessibility, a lot of efforts are made by researchers in order to understand how biomechanical data (joint angles and loads) are related to discomfort perception. However, for such complex tasks, one has to check that the compared motions are realized with the same strategy and coordination. This paper proposes therefore two different methods to categorize different motion coordinations. The first method is based on kinematic data (key frames of the motion) and the second method on dynamic data (contact and joint loads). The results show that the description of coordinations based on kinematics or dynamics can lead to slightly different categories. As for truck accessibility, if both methods give complementary information, the categories defined dynamically refine the ones defined with kinematic considerations.
Summary Podium 4_1
Head and trunk mass and 3D center of mass position estimation in scoliotic girls
Allard, P.a, Damavandi, M.a,b, Dalleau, G.c, Stylianides, G.d, and Rivard, C.H.a
Laboratoire d’Étude du Mouvement, Sainte-Justine Hospital, University of Montreal, Montreal, Canada
Department of Kinesiology, Tarbiat Moallem University of Sabzevar, Sabzevar, Iran
Faculté des Sciences de l’Homme et de l’Environnement, Université de la Réunion, Le Tampon, France
Department of Exercise Science and Sport, University of Scranton, PA, USA
Though body segment masses and center of mass (COM) position are often calculated from anthropometric tables their applications are questionable for scoliotic patients. The objectives of this study are to estimate the head and trunk mass and center of mass position using the personalized in-vivo force plate method described by Damavandi et al. (2009) in 20 able-bodied and 21 scoliotic girls. The head and trunk COM positions were afterwards compared to those of the whole body to estimate trunk offset. It was observed that the relative mass of the head and trunk to that of the whole body in scoliotic girls was higher compared to non-scoliotic girls. The horizontal position of COM of the head and trunk segment of scoliotic girls was more to the right and posterior compared to the able-bodied girls but their COM’s height was similar. The anteroposterior offset was larger in scoliotic girls with the whole body COM anterior to that of the head and trunk segment. This could be explained by a greater pelvic forward tilt and a greater backward trunk inclination in scoliotic girls compared to able-bodied subjects. It appears that the COM position of the head and trunk is related to the trunk inclination in non-treated scoliotic girls.
Summary Podium 4_2
Multi-segment trunk kinematics
Intra/Inter subject variability during locomotion and elementary exercises
Alberto Leardini, Fabio Biagi, Andrea Merlo, Claudio Belvedere, Maria Grazia Benedetti
Movement Analysis Laboratory, Istituto Ortopedico Rizzoli; AUSL di Reggio Emilia
Bologna, Italy; Correggio, Italy
This study analyzed the amount and the consistency of natural motion at the trunk anatomical complex. This is performed at several different segments: thorax and pelvis in 3D, shoulder and seven line segments in the spine in 2D. This motion was tracked during locomotion and elementary exercises by 14 markers, by standard conventions and terminology. One volunteer was analysed for intra-subject repeatability over ten repetitions, and ten volunteers were analysed for inter-subject variability. For most of the rotations intra-subject repeatability was good, i.e. mean standard deviation over the cycle smaller than 2°, however smaller than 10% of the range of motion, better in the more constrained motor tasks (gait, stair, chair). Inter-subject variability was large for flexion/extension, i.e. mean standard deviation between 4.5° ÷ 10.5° and 3.3° ÷ 15.1° respectively during constrained motor task and elementary exercises. These different patterns of motion suggest different strategies are adopted at this multi-articulated complex. The new protocol is a step forward in resolution with respect to the current models, and should enhance the comprehension of relevant physiological motion.
Summary Podium 4_3
Comparison of Distributed and Concentrated Markers Configurations for the Measurement of 3D Spinal Motion
J. Favre1, L. Rime, H. Varrin, C. Schizas, B. Jolles, K. Aminian
Laboratory of Movement Analysis and Measurement, EPFL, Lausanne, Switzerland
Department of Mechanical Engineering, Stanford University, Stanford, California
Department of Orthopaedic Surgery and Traumatology, CHUV, Lausanne, Switzerland
There is a need to improve knowledge about spinal disorders and treatments. 3D kinematics measurement is a key part in this process. Thanks to the progress of camera-based systems, finer multi-segments models with more freedom regarding markers placement can now be considered. This study aimed at comparing two common markers configurations using either single markers distributed on the back or triads of markers concentrated along the spine. To this end, the rigidity of five spinal subdivisions (i.e., head, upper thoracic, lower thoracic, lumbar and pelvis) were assessed during gait. Then, 3D inter-segment angular displacements obtained through both configurations were analyzed. The results showed that only the head could be considered as rigid and that the markers configuration influenced the orientation measurement for the other segments. The markers configuration also strongly affected the angular displacements. In conclusion, this study brought essential elements regarding the monitoring of spinal motion through multi-segments models.
Summary Podium 5_1
Computer Analysis and Simulation of the Flight Phase of Figure Skating Jumps
Thomas Kepple, Sarah Trager, Jeff Matson and James Richards
Department of Health Nutrition and Exercise Science
University of Delaware
Newark, DE USA
When performing jumps skaters need to complete enough rotations to land in the required position. The ability to optimize in-flight position would be an aid to skaters attempting to land jumps. For this study, the flight phase of figure skating jumps was simulated for four high level skaters. .The simulation software, which used motion capture data as input, allowed the authors manipulated the joint positions during flight looking for improvement in the ability to complete the jumps. The simulation indicated that all four skaters tested could increase the spin by between one third and one full revolution. The authors were able to monitor the implementation of the recommended improvement for one skater. The subject reported “My landings were a lot more solid,” she said “It definitely proved itself.” This anecdotal evidence lends support to the proposed approach as a powerful tool for potentially optimizing the performance of skaters.
Summary Podium 5_2
Muscle Contributions to Propulsion and Support During Running
An Induced Acceleration Analysis with a Novel Foot-Floor Constraint
Samuel R. Hamner, Ajay Seth, and Scott L. Delp
Departments of Mechanical Engineering and Bioengineering
Stanford University
Stanford, California, USA
Muscles actuate running by developing forces that propel the body forward while supporting the body’s weight. To understand how individual muscles contribute to propulsion and support during running we developed a three-dimensional muscle actuated simulation of the running gait cycle. The simulation is driven by 92 muscles of the lower extremities and torso. We analyzed the simulation to determine how each muscle contributed to the horizontal and vertical accelerations of the body mass center. During the early part of the stance phase, the quadriceps muscle group was the largest contributor to braking (i.e., backward acceleration) and support (i.e., vertical acceleration). During the second half of the stance phase, the soleus and gastrocnemius became the greatest contributors to propulsion (i.e., forward acceleration) and support. Analysis of the simulation provided new insights into the actions of muscles during running and is freely available on-line (www.simtk.org) allowing other researchers to reproduce the results and perform additional analyses.
Summary Podium 5_3
Posture Influences Ground Reaction Force: Implications for Crouch Gait
Hoa X. Hoang and Jeffrey A. Reinbolt
Mechanical, Aerospace, & Biomedical Engineering
The University of Tennessee
Knoxville, TN USA
Crouch gait, a common condition among children with cerebral palsy, decreases walking efficiency due to the increased knee and hip flexion during the stance phase of gait. However, a crouch posture may afford biomechanical advantages that lead some patients to adopt a crouch gait. In this study, we evaluated one possible benefit of crouch gait. The objective was to determine if posture influences the muscles’ capacity to generate ground reaction forces in the transverse plane. A three-dimensional musculoskeletal model created in OpenSim was used to perform a series of optimizations for the 8 directions of a compass. We found that a crouched posture had the largest ground reaction force averaged in all directions and the largest ground reaction force profile. This increase in muscle capacity while in a crouched posture may allow a patient to generate new movements to compensate for impairments associated with cerebral palsy.
Summary Podium 6_1
Dense Marker-less Three Dimensional Motion Capture
Søren Hauberg, Bente Rona Jensen, Morten Engell-Nørregård, Kenny Erleben, Kim Steenstrup Pedersen
eScience Centre, Dept. of Computer Science
Laboratory of Biomechanics and Motor Control, Dept. of Exercise and Sport Sciences
University of Copenhagen
Copenhagen, Denmark
We present a Computer Vision based Motion Capture setup, that is cheap, versatile and non-intrusive, i.e. it does not require markers. The system is based on a single stereo camera that provides a dense set of three dimensional points on the test subject. A pose model is then fitted to these dense points using a Particle Filter. Since only a single stereo camera is required, the system shows great versatility: no markers are needed, calibration is only needed once and the camera can be moved during the experiments. While results are promising, they are not yet competitive with commercial motion capture systems, but shows promise as a flexible low cost system.
Summary Podium 6_2
Orientation of body segments in ski jumps using wearable sensors:
Analysis of relevant parameters during stable flight phase
K. Aminian, J. Chardonnens, J. Favre1, F. Cuendet, G. Gremion
Laboratory of Movement Analysis and Measurement, EPFL, Lausanne, Switzerland
Swiss-Ski, Bern, Switzerland
Swiss Olympic Center, CHUV, Lausanne, Switzerland
3D kinematic and dynamic analysis is highly required in ski jumping. Current recording techniques (e.g. camera systems) suffered from limitations, such as volume capture or complexity of use and processing. This study proposed a new 3D approach based on inertial sensors to calculate automatically the whole body segments orientation of the entire jump during in-field measurements. Combination of accelerometers and gyroscopes allowed devising a functional calibration procedure adapted to ski jumping activity. Then, segments orientation was obtained based on strapdown integration of gyroscopes. Finally, accelerometers were used to define in-run initial orientations and to improve segments orientations during stable flight. In order to show the efficacy of the proposed system, relevant 3D parameters of stable flight phase (V-and attack ski angles, joint angles, drag and lift forces) were extracted from 86 jumps of 34 jumpers. Combination of these parameters expressed 55% of whole variance of distance score.
Summary Podium 6_3
3D Gait assessment using wearable inertial sensors: walking performance in young and elderly subjects
Kamiar Aminian, Benoit Mariani, Constanze Hoskovec, Stephane Rochat, Christophe Büla, Julien Penders
Laboratory of Movement Analysis and Measurements, Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne, Switzerland
Service of Geriatric Medicine, CHUV & CUTR Sylvana, Epalinges, Switzerland
Holst Centre, IMEC, High Tech Campus 31, Eindhoven, The Netherlands
We propose a new 3D gait analysis method based on foot-worn inertial sensors, which is wearable and can be used outdoor and during long distance walking. By processing foot angular velocities and accelerations, an algorithm was devised to detect each gait cycle during straight walking and turning, and to estimate common spatio-temporal gait parameters (i.e. Stride Length and Stride Velocity), as well as new gait metrics such as Turning Angle or Foot Clearance. The performance of the system was validated against a reference optical motion capture, during a clinical protocol involving young and elderly subjects. Finally, a 6 Minute Walk Test was performed, and used to compare Young and Elderly group of subjects. Metrics provided by the system, especially Foot Clearance and Turning Angle, which are rarely used in unconstrained gait analysis due to the difficulty of their measurement, appeared to be relevant for clinical evaluation.
Summary Poster 1
WITHDRAWN
Use of Motion Capturing Systems in the Evaluation of Joint Replacement Surgeries
Case Study: Total Hip Replacement
Stephanie Bonin, Moataz Eltoukhy, Shihab Asfour, W. Andrew Hodge
Department of Industrial Engineering, College of Engineering, University of Miami, USA
Institute for Mobility and Longevity, Jupiter, FL, USA
Summary Poster 2
WITHDRAWN
Measuring Dynamic Alignment of The Knee
Wangdo Kim, Veronica Vleck, Antonio Veloso, John Tan, Carlos Andrade
Technical University of Lisbon, Estrada da Costa, Cruz Quebrada, Portugal
Physical Education & Sports Science, National Institute of Education, Singapore
Summary Poster 3
The Helical Axes of the Tibio-Femoral and Patello-Femoral Joints
An in-vitro study
Belvedere C., Leardini A., Ensini A., Cenni F., Biagi F., Giannini S., Catani F.
Movement Analysis Laboratory and Department of Orthopedic Surgery
Istituto Ortopedico Rizzoli
Bologna, Italy
The aim of this study was to possibly take advantage of the instantaneous and mean helical axis concepts (IHA/MHA), for patient-specific navigated surgery of the human knee; in particular the axes derived from both the tradition tibio-femoral (TFJ) and original patello-femoral (PFJ) joint kinematics during knee passive flexion were exploited.
Sixteen knees from leg amputation were analyzed by means of a surgical navigation system with marker
cluster fixed on the femur, tibia and patella. Five trials of passive knee flexions were performed with a 100N pulling-force on the quadriceps.
All helical axis parameters were found generally reproducible intra-specimen. Over specimens, these were generally more repeatable when derived from PFJ than from TFJ kinematics. With respect to the femur anatomical reference axes, TFJ-MHA orientation was 1.7°±3.0° adducted and 4.8°±3.9° externally rotated; PFJ-MHA orientation was 0.1°±4.3° adducted and 0.6°±4.0° externally rotated.
These results suggest that, over the same knee motion, the reproducibility of the PFJ-MHA is higher than that of TFJ-MHA. These findings can be very useful in the enhancement of prosthesis design and surgical techniques for total knee arthroplasty.
Summary Poster 4
Comparing Knee Joint Center Positions Measured with Biplanar Fluoroscopy and Skin Mounted Markers
Alison Sheets, Sean Scanlan, Jake Krong, Erik Giphart, Ajit Chaudhari, Michael Torry, Thomas Andriacchi
Stanford University, Stanford, CA, USA
Palo Alto Veterans Affairs, Bone and Joint Center, Palo Alto, CA, USA
Steadman-Philippon Research Institute, Biomechanics Laboratory, Vail, CO, USA
Ohio State University, Columbus, OH, USA
Knee joint center (JC) positions during the impact and loading phase of over-ground walking were simultaneously measured using biplane fluoroscopy and skin-mounted markers, and effects of measurement differences on net knee adduction moments were quantified. Fluoroscopic measurements were made by tracking each frame of the walking trials using subject-specific tibia and femur bone models made from CT scans. Optical marker measurements were made using the Point Cluster Technique, and with markers on the medial and lateral tibial plateau. Fluoroscopic and marker-based anatomic coordinate systems for each subject were aligned using a standing-reference trial. Measured knee JC positions differed by less than 5mm for each of the three healthy male subjects, and these variations resulted in net knee adduction moment differences of 1-6%. Studies comparing marker-based and imaging measurements may improve the understanding of both systems, and could lead to the quantification of, and correction for, skin motion during dynamic activities.
Summary Poster 5
Effects of Intensive Reach Forward Practices While Standing on Reach Movement in Healthy Young Adults: A Pilot Study
Fang-Ting Tsai, Yung-Chun Hung, Ya-Jhu Jhong, Chia-Fang Liao,Wen-Yu Liu, Chih-Hsiu Cheng
Department of Physical Therapy and Graduate School of Rehabilitation Science
Chang Gung University
Tao-Yuan, Taiwan
The purposes of this pilot study were to describe the changes of reach movement after intensive reach forward task practices in healthy young adults. Eight young healthy adults (4 females and 4 males; mean age of 22.63±2.26 years; mean height of 166.25±12.19 cm; mean weight of 59±12.69 kg) consented to participate. Within one day, all subjects practiced the forward reaching to a moving target for a total of sixty trials (fifteen trials, four blocks) using their dominant arms while standing. The movement of a marker placed on the wrist had been used as an index of hand transport by a VICON 370 system. Repeated measure ANOVA was used to compare the changes of reach movement among the four blocks. The results implied that healthy subjects would fine-tune their reach movements after repetitively practices on functional forward reach task by generating a quick first reach movement unit.
Summary Poster 6
3D analysis to reveal muscle activity timing in object replacing arm movements
Jozsef Laczko and Robert Tibold
Dept. of Biomechanics Semmelweis University, TF Budapest, Hungary
Faculty of Information Technology, Pazmany Peter Catholic University, Budapest, Hungary
Analysis of healthy human limb movements is applied to improve control strategies for medical rehabilitation techniques as functional electrical stimulation. One issue is the generation of joint torques by artificial activation of muscle groups. 3D modeling allows assessment of muscle forces and joint torques. Subjects performed arm movements having objects with different masses in their hand. Coordinates of anatomical landmarks were measured. 3D angular acceleration, muscle moment arms and the arm’s inertial parameters were calculated to establish torques in the shoulder and elbow. Using modeled joint torques and simulated muscle geometry, flexor and extensor muscle forces were computed that would lead to measured changes in arm kinematics. The effect of gravity and load were considered. Dependence of muscle activity timing on object’s mass is studied assuming that in each joint one of the two muscle groups is activated to rotate the segments at any instant around desired angular acceleration vector.
Summary Poster 7
Effect of Reaction Force Direction and Elbow Position on Mechanical Load Distribution in Wheelchair Propulsion
Joseph M Munaretto, Jill L Mcnitt¬Gray, Henryk Flashner, Phil Requejo
Departments of Biomedical Engineering, Kinesiology, Biological Sciences, Aerospace and Mechanical Engineering
University of Southern California Los Angeles, CA, USA
The repetitive nature and mechanical demand imposed on the upper extremity during manual wheelchair propulsion is associated with overuse injuries of the shoulder. Simulations exploring how wheelchair users can orientate the hand / pushrim reaction force and elbow positions provide a means of determining how subjects with different capacities can redistribute mechanical load. A two segment, 3D inverse dynamic model was used to simulate mechanical load while changing the radial force, medial¬lateral force, and elbow position. We hypothesized that NJM demand would not be minimal when reaction force was tangential. Results showed that minimum NJM cost did not occur when the hand/pushrim force was tangential to the wheel and that the required medial¬lateral force to minimize NJM cost was a function of elbow position. Distribution of total NJM was primarily placed on the shoulder and suggests that kinematic configuration of the upper extremity may affect ability to redistribute load.
Summary Poster 8
Scapular movement estimation by single and double calibration: preliminary results
Lempereur M., Brochard S., Rémy-Néris
CHU Brest, Service de médecine physique et de réadaptation
Inserm
Université Européenne de Bretagne
Brest, France
The International Society of Biomechanics recommends the placement of 3 anatomical markers on scapula to track its movement. An acromion marker cluster can also provide the measurement of the scapula. Measurement errors have been reported for high humeral elevations for both methods. In order to reduce the error, a new method of scapular motion estimation is developed. This method is based on two calibrations taken at the extremes of the movement as described by Cappello et al. (2005). The aim of this study is to compare the accuracy of the single and double calibration during large arm flexion using the palpation to serve as reference. Six healthy subjects took part in the experiments. The first results showed that the single calibration tends to over-estimated the scapular movement. Indeed, the error is inferior to 5° regardless the axis of the scapular rotation and the humeral elevation.
Summary Poster 9
Improving Computed Muscle Control through Optimization to Generate Dynamic Simulations of Overground Running
Jeffrey A. Reinbolt and Cyril J. Donnelly
Mechanical, Aerospace, & Biomedical Engineering, The University of Tennessee, Knoxville, USA
School of Sport Science, Exercise and Health, The University of Western Australia, Perth, AU
Musculoskeletal conditions cost the US economy $849 billion per year. Simulations can potentially revolutionize medicine by enabling engineers and clinicians to ask “what if” questions that investigate musculoskeletal conditions and treatment outcomes. Three main articles describing computed muscle control, an increasingly popular choice to rapidly generate forward dynamic simulations, have nearly 100 citations. Most studies do not report the days or weeks required in choosing input parameters for computed muscle control that successfully produce a reasonable simulation and measures of the simulation’s unreasonabilitys. We used optimization to minimize measures of an unreasonable simulation by adjusting input parameters for computed muscle control. Within hours, optimal input parameters were found that produced a simulation closely tracking experimental data of overground running. Improving computed muscle control through optimization allows engineers and clinicians to produce a reasonable simulation within a modest time and without choosing unnecessary input parameters.
Summary Poster 10
A simulation to describe the effects of in-shoe orthoses
Dr Gunther Paul, Chris Bishop, Mike Arakilo, Dr Dominic Thewlis
University of South Australia
Adelaide, South Australia
The subtalar joint has been presumed to account for most of the pathologic motion in the foot and ankle, but research has shown that motion at other foot joints is greater than traditionally expected. Although recent research demonstrates the complexity of the kinematic variables in the foot and ankle, it still fails to expand our knowledge of the role of the musculotendinous structures in the biomechanics of the foot and ankle and how this is affected by in-shoe orthoses. The aim of this study was to simulate the effect of in-shoe foot orthoses by manipulation of the ground reaction force (GRF) components and centre of pressure (CoP) to demonstrate the resultant effect on muscle force in selected muscles during both the rearfoot loading response and stance phase of the gait cycle. We found that any medial wedge increases ankle joint load during gait cycle, while a lateral wedge decreases the joint load during the stance phase.
Summary Poster 11
Continuous Center of Mass Displacement Estimation During Walking Comparison between MVN and the ForceShoe
H. Martin Schepers, Daniel Roetenberg, Peter H. Veltink, Henk J. Luinge
Xsens Technologies B.V., Enschede, The Netherlands
Institute for BioMedical Technology (BMTI), University of Twente, Enschede, The Netherlands
The Center of Mass (CoM), the point where the total human body mass can be assumed to be concentrated, is an essential variable for balance assessment. This study shows a comparison between MVN and the ForceShoe, two ambulatory measurement systems, for continuous CoM displacement estimation during walking. The MVN system is a 6 DOF human motion analysis system using inertial sensors. The ForceShoe consists of an orthopaedic sandal with a 6 DOF force/moment sensor and an inertial sensor attached to the heel and the forefoot. CoM displacement using MVN was estimated by a weighted sum of segment CoM positions. CoM displacement using the ForceShoe was estimated by fusing low-pass filtered center of pressure data with high-pass filtered double integrated CoM acceleration obtained from the ground reaction force. Several walking trials were performed by a subject wearing a MVN suit and the ForceShoes. Both measurement systems showed good correspondence, as shown by the RMS differences between both measurement systems, being 0.05 ± 0.01 m. It is concluded that MVN and the ForceShoe are two promising tools for continuous CoM displacement estimation during walking.
Summary Poster 12
Development of a protocol for the use of inertial sensors in large scale gait analysis in a clinical environment
R.G. Morris and S.E.M. Lawson
Bioengineering Research Group School of Mechanical & Systems Engineering
Newcastle University Newcastle upon Tyne, U.K.
The kinematics of gait and the absorption of impact are thought to play an important role in the etiology of osteoarthritis. A protocol was developed to allow gait analysis data collection in a clinical environment using inertial sensors. Attachment positions of the sensors were validated by displacement from their intended position. The effect of adipose tissue, sampling rate and material types was also assessed. Repeatability of the sensors for joint ranges of motion in the sagittal plane (mean±SD, hip 49.0±1.28°, knee 61.5±1.28°, ankle 33.5±0.69°) was comparable to that reported for an opto-electronic system (45±1.8, 63±1.9, 36±1.5). Displacement of the femoral sensor had the greatest effect on repeatability (hip 52±3.22, knee 62.5±2.91). Denim produced the greatest decrease in repeatability (hip 50.0±2.04, knee 61.0±1.75). Sampling rate and adipose tissue simulation had negligible effect. An attachment position that minimises sensor movement artifact produced the greatest repeatability, irrespective of proximity to bony landmarks.
Summary Poster 13
Joint Angles And Segment Length Estimation Using Inertial Sensors
Daniel Roetenberg, Linda Schipper, Pietro Garofalo, Andrea Cutti, Henk Luinge
Xsens Technologies, B.V. , Enschede, The Netherlands
DEIS, Department of Electronics, Computer Science and Systems, University of Bologna (BO), Italy
I.N.A.I.L. Prostheses Centre, Vigorso di Budrio (BO), Italy
This abstract describes a novel and accurate method for 3D joint angles estimation using inertial sensors. It does not use magnetometers or the local magnetic field to stabilize heading. Exact joint location are accurately estimated in-use, allowing for patient specific scaling and tracking of movement.
Summary Poster 14
Towards a wearable cricket bowling sensor.
Andrew Wixted, Marc Portus, Daniel James1, Wayne Spratford, Mark Davis
Centre for Wireless Monitoring & Applications, Griffith University, Nathan Qld.,4111, Australia
Sport Science Sport Medicine Unit, Cricket Australia Centre of Excellence
Biomechanics Department, Australian Institute of Sport
In the sport of cricket, it is a requirement that when the bowler bowls the ball, the elbow does not extend by more than 15 degrees during the delivery. Extension greater than 15 degrees is considered a throw, and any bowler who appears to throw the ball may be reported by cricket umpires. Once reported, the bowler’s action is tested in a biomechanics laboratory.
As laboratory testing is time consuming, expensive and suffers from lower ecological validity, it is desirable to measure bowling elbow kinematics in match conditions without any encumbrance to the athlete. The use of wearable MEMS gyroscopic and accelerometer inertial sensors is the subject of this research and development program.
In this preliminary research, existing motion capture data was processed to generate the acceleration and rotation rates that would be recorded by 3D accelerometer and gyroscopic inertial sensors. This data was analyzed, identifying various bowling action signatures.
Summary Poster 15
Feasibility and sense of instant ambulatory feedback of cyclical 3D kinematics
(Examined in rowing)
Chris Baten, Marieke ter Voert, Remon van der Aa and Ruben Wassink
Group 3D Analysis of Human Movement
Roessingh Research and Development
Enschede, Netherlands
Recently developed ambulatory methods for 3D analysis of human movement based on inertial sensing hold the promise of practical large scale application in every day situations. Still very few practical applications have been developed so far. This paper examines the feasibility as well as sense of using these methods for instant feedback in cyclical movements, to start with in rowing.. 10 experienced male rowers each performed one 20 minute rowing session on a RowPerFect dynamic row ergometer maintaining a minimum heart rate of 85% of HRmaxdback. 5 returned for another session. Kinematic pattern features related to typical coachable coordination patterns were found with magnitudes much larger than the smallest detectable difference values found. As also was shown that the method is feasible in actual rowing the successful development of a rowing coach assistant seems feasible and sensible.
Summary Poster 16
Influence of kinematic variability on motion perception in 2D and 3D
Pierfrancesco Celada, Siân E. M. Lawson
Bioengineering group, School of Mechanical and Systems Engineering
Newcastle University, Newcastle upon Tyne
Perception of kinematic variability can be an important part of clinical assessment and is of great economic relevance to the visual effects and entertainment industry. The aim of this study was to evaluate the ability of human observers to obtain musculo-skeletal size-related information from kinematics; investigating its availability and usability from a visual form. Two series of perception tests, displayed with two-dimensional and three-dimensional setups were designed to analyze observers’ perceptual abilities and sensitivity in discriminating the size of a graphic character from its motion. Ad hoc modifications of angular velocity and gait frequency profiles are able to induce in an observer a particular perception of size. The dimensionality of the representation affected observers’ judgments. These findings may have important applications in the retargeting process of animation for the entertainment industry, and in visual gait assessment.
Summary Poster 17
Movement pattern characteristics: Factor analysis for 3-D movements in patients with shoulder impingement
Han- Yi Huang, Wei- Cheng Cheng, Cheng-Ju Hung, Jiu- Jenq Lin
School and Graduate Institute of Physical Therapy
College of Medicine, National Taiwan University
Taipei, Taiwan ROC
Abnormal scapulothoracic kinematic is thought to play an important role in subacromioal syndrome (SAIS). The purpose of this study was to use the factor analysis to investigate the time- series movement pattern of an individual subject with different stage/disability. Eight subjects performed the elevation of the arm in scapular plane by self-selecting end target. Kinematic data was collected by FASTRAK 3-D electromagnetic motion-capturing system. Four kinematic variables (scapular tipping/ protraction/ upward rotation and humerus elevation) were entered into factor analysis to determine the time-series movement pattern in each subject. In subjects of early stage, the score coefficient of scapular protraction is higher than 0.50. In subjects of chronic stage, the score coefficient of scapular tipping is higher than 0.50. There is no similar movement pattern on the disability effect. The factor analysis method seems to be a potential tool to investigate the dynamic time-series movement pattern.
Summary Poster 18
3D Motion Analysis of Human Body During Hippotherapy
Miloslav Vilimek and Tomas Goldmann
Department of Mechanics, Biomechanics and Mechatronics
Faculty of Mechanical Engineering, Czech technical University in Prague
Prague, Czech Republic
This research project deals with movement and muscular activity analysis of human trunk during hippotherapy. Hippotherapy is a form of physical and occupational therapy in which a therapist uses the characteristic movements of a horse to provide carefully graded sensory input. In this experimental study we would like to find out suitable methods that could be used for description of biomechanical reactions of passive horse-rider. In order to solve this task, telemetric surface EMG and 3D motion analysis were used. The body of experimental rider had installed markers on anatomical significant points for movement identification. By this experiment was described the vertical movement provides the same attributes for all investigated points while the lateral shift is variable for each point. Side shift of lumbar spine correlates with horse trunk movement. The upper spine is moving with different frequency and range of motion then lower spine.
Summary Poster 19
WITHDRAWN
3 D Angular Momentum as a Metric of Gait in Typically Developing Children and Children with Cerebral Palsy
Bradford C. Bennett, Shawn D. Russell, Chris Zirker, Thomas Robert, & Mark F. Abel
Dept. of Orthopaedic Surgery, Dept. of Mech. & Aerospace Engr., INRETS
University of Virginia, Charlottesville, VA, USA
Universite’ de Lyon, Lyon, France