Internal Tibial Forces and Moments During Graded Running

Author(s):  
Michael Baggaley ◽  
Timothy R. Derrick ◽  
Gianluca Vernillo ◽  
Guillaume Millet ◽  
W. Brent Edwards

Abstract This note is to correct errata in the paper "Internal Tibial Forces and Moments During Graded Running" published in Journal of Biomechanical Engineering, Vol. 144, p. 011009 (2021), DOI: 10.1115/1.4051924. In the Data Analysis section, it was stated that, "The joint moments used in the optimization were the flexion-extension and abduction-adduction moments at the hip and ankle, and the flexion-extension moment at the knee." However, it has come to our attention that this is incorrect, and instead the joint moments used in the static optimization routine were the flexion-extension and abduction-adduction moments at the hip, and the flexion-extension moment at the knee and ankle. Please accept our apologies for the error.

2005 ◽  
Vol 29 (3) ◽  
pp. 255-267 ◽  
Author(s):  
J. M. van Velzen ◽  
H. Houdijk ◽  
W. Polomski ◽  
C. A. M. van Bennekom

The purpose of the study was to investigate which systematic effects of prosthetic misalignment could be observed with the use of the SYBAR system. The alignment of the prosthesis of five well-trained unilateral trans-tibial amputees was changed 158 in magnitude in varus, valgus, flexion, extension, endorotation, exorotation, dorsal flexion, and plantar flexion. Subjects walked over a distance of 8 m at a self-selected walking speed with the alignment of the prosthesis as it was at the start of the experiment (reference) and with each changed alignment. Two video cameras (frontal and sagittal) and a force plate of the SYBAR system (Noldus Information Technology, The Netherlands) were used to capture gait characteristics of the subjects. Temporal and spatial characteristics, the magnitude and timing of the ground reaction force (GRF), and the external joint moments were derived from these data. Despite the substantial perturbations to prosthetic alignment, only a few effects were observed in the temporal and spatial characteristics of gait, the magnitude and timing of the GRF, and the external joint moments. Only the pattern of the ground reaction force in the mediolateral direction and the joint moment around the ankle in the frontal plane during terminal stance showed a systematic effect when the alignment was set into varus and valgus or exorotation. It was concluded that using the SYBAR system in this study revealed little effect of perturbations in prosthetic alignment, for this group of patients, and for the selected parameters. It was questioned whether this is due to the relatively low resolution of the SYBAR system or the capacity of the well-trained subjects to compensate for the disturbance in alignment. It was suggested that the usability of the SYBAR system in clinical settings should be further explored.


2014 ◽  
Vol 30 (3) ◽  
pp. 431-438 ◽  
Author(s):  
Goeran Fiedler ◽  
Brooke Slavens ◽  
Roger O. Smith ◽  
Douglas Briggs ◽  
Brian J. Hafner

Prosthesis-integrated sensors are appealing for use in clinical settings where gait analysis equipment is unavailable, but accurate knowledge of patients’ performance is desired. Data obtained from load cells (inferring joint moments) may aid clinicians in the prescription, alignment, and gait rehabilitation of persons with limb loss. The purpose of this study was to assess the accuracy of prosthesis-integrated load cells for routine use in clinical practice. Level ground walking of persons with transtibial amputation was concurrently measured with a commercially available prosthesis-integrated load cell, a 10-camera motion analysis system, and piezoelectric force plates. Ankle and knee flexion/extension moments were derived and measurement methods were compared via correlation analysis. Pearson correlation coefficients ranged from 0.661 for ankle pronation/supination moments to 0.915 for ankle flexion/extension moments (P < .001). Root mean squared errors between measurement methods were in the magnitude of 10% of the measured range and were explainable. Differences in results depicted differences between systems in definition and computation of measurement variables. They may not limit clinical use of the load cell, but should be considered when data are compared directly to conventional gait analysis data. Construct validity of the load cell (ie, ability to measure joint moments in-situ) is supported by the study results.


2020 ◽  
Vol 10 (7) ◽  
pp. 2493 ◽  
Author(s):  
Muhammad Athif Mat Zin ◽  
Azmin Sham Rambely ◽  
Noratiqah Mohd Ariff ◽  
Muhammad Shahimi Ariffin

Smoothing is one of the fundamental procedures in functional data analysis (FDA). The smoothing parameter λ influences data smoothness and fitting, which is governed by selecting automatic methods, namely, cross-validation (CV) and generalized cross-validation (GCV) or subjective assessment. However, previous biomechanics research has only applied subjective assessment in choosing optimal λ without using any automatic methods beforehand. None of that research demonstrated how the subjective assessment was made. Thus, the goal of this research was to apply the FDA method to smoothing and differentiating kinematic data, specifically right hip flexion/extension (F/E) angle during the American kettlebell swing (AKS) and determine the optimal λ . CV and GCV were applied prior to the subjective assessment with various values of λ together with cubic and quintic spline (B-spline) bases using the FDA approach. The selection of optimal λ was based on smoothed and well-fitted first and second derivatives. The chosen optimal λ was 1 × 10 − 12 with a quintic spline (B-spline) basis and penalized fourth-order derivative. Quintic spline is a better smoothing and differentiation method compared to cubic spline, as it does not produce zero acceleration at endpoints. CV and GCV did not give optimal λ , forcing subjective assessment to be employed instead.


2019 ◽  
Author(s):  
Florian Michaud ◽  
Mohammad S. Shourijeh ◽  
Benjamin J. Fregly ◽  
Javier Cuadrado

AbstractDetermination of muscle forces during motion can help to understand motor control, assess pathological movement, diagnose neuromuscular disorders, or estimate joint loads. Difficulty of in vivo measurement made computational analysis become a common alternative in which, as several muscles serve each degree of freedom, the muscle redundancy problem must be solved. Unlike static optimization (SO), synergy optimization (SynO) couples muscle activations across all time frames, thereby altering estimated muscle co-contraction. This study explores whether the use of a muscle synergy structure within a static optimization framework improves prediction of muscle activations during walking. A motion/force/EMG gait analysis was performed on five healthy subjects. A musculoskeletal model of the right leg actuated by 43 Hill-type muscles was scaled to each subject and used to calculate joint moments, muscle-tendon kinematics and moment arms. Muscle activations were then estimated using SynO with two to six synergies and traditional SO, and these estimates were compared with EMG measurements. SynO neither improved SO prediction of experimental activation patterns nor provided SO exact matching of joint moments. Finally, synergy analysis was performed on SO estimated activations, being found that the reconstructed activations produced poor matching of experimental activations and joint moments. As conclusion, it can be said that, although SynO did not improve prediction of muscle activations during gait, its reduced dimensional control space could be beneficial for applications such as functional electrical stimulation (FES) or motion control and prediction.


2021 ◽  
Vol 11 (24) ◽  
pp. 12054
Author(s):  
Neila Mezghani ◽  
Rayan Soltana ◽  
Youssef Ouakrim ◽  
Alix Cagnin ◽  
Alexandre Fuentes ◽  
...  

The purpose of this study is to identify healthy phenotypes in knee kinematics based on clustering data analysis. Our analysis uses the 3D knee kinematics curves, namely, flexion/extension, abduction/adduction, and tibial internal/external rotation, measured via a KneeKG™ system during a gait task. We investigated two data representation approaches that are based on the joint analysis of the three dimensions. The first is a global approach that is considered a concatenation of the kinematic data without any dimensionality reduction. The second is a local approach that is considered a set of 69 biomechanical parameters of interest extracted from the 3D kinematic curves. The data representations are followed by a clustering process, based on the BIRCH (balanced iterative reducing and clustering using hierarchies) discriminant model, to separate 3D knee kinematics into homogeneous groups or clusters. Phenotypes were obtained by averaging those groups. We validated the clusters using inter-cluster correlation and statistical hypothesis tests. The simulation results showed that the global approach is more efficient, and it allows the identification of three descriptive 3D kinematic phenotypes within a healthy knee population.


Author(s):  
Pavlos Silvestros ◽  
Claudio Pizzolato ◽  
David G. Lloyd ◽  
Ezio Preatoni ◽  
Harinderjit S. Gill ◽  
...  

Abstract Knowledge of neck muscle activation strategies prior to sporting impacts is crucial for investigating mechanisms of severe spinal injuries. However, measurement of muscle activations during impacts is experimentally challenging and computational estimations are not often guided by experimental measurements. We investigated neck muscle activations prior to impacts with the use of electromyography (EMG)-assisted neuromusculoskeletal models. Kinematics and EMG recordings from four major neck muscles of a rugby player were experimentally measured during rugby activities. A subject-specific musculoskeletal model was created with muscle parameters informed from MRI measurements. The model was used in the Calibrated EMG-Informed Neuromusculoskeletal Modelling toolbox and three neural solutions were compared: i) static optimisation (SO), ii) EMG-assisted (EMGa) and iii) MRI-informed EMG-assisted (EMGaMRI). EMGaMRI and EMGa significantly (p¡0.01) outperformed SO when tracking cervical spine net joint moments from inverse dynamics in flexion/extension (RMSE = 0.95, 1.14 and 2.32 Nm) but not in lateral bending (RMSE = 1.07, 2.07 and 0.84 Nm). EMG-assisted solutions generated physiological muscle activation patterns and maintained experimental co-contractions significantly (p¡0.01) outperforming SO, which was characterised by saturation and non-physiological "on-off" patterns. This study showed for the first time that physiological neck muscle activations and cervical spine net joint moments can be estimated without assumed a priori objective criteria prior to impacts. Future studies could use this technique to provide detailed initial loading conditions for theoretical simulations of neck injury during impacts.


Author(s):  
P. Ingram

It is well established that unique physiological information can be obtained by rapidly freezing cells in various functional states and analyzing the cell element content and distribution by electron probe x-ray microanalysis. (The other techniques of microanalysis that are amenable to imaging, such as electron energy loss spectroscopy, secondary ion mass spectroscopy, particle induced x-ray emission etc., are not addressed in this tutorial.) However, the usual processes of data acquisition are labor intensive and lengthy, requiring that x-ray counts be collected from individually selected regions of each cell in question and that data analysis be performed subsequent to data collection. A judicious combination of quantitative elemental maps and static raster probes adds not only an additional overall perception of what is occurring during a particular biological manipulation or event, but substantially increases data productivity. Recent advances in microcomputer instrumentation and software have made readily feasible the acquisition and processing of digital quantitative x-ray maps of one to several cells.


2020 ◽  
Vol 5 (1) ◽  
pp. 290-303
Author(s):  
P. Charlie Buckley ◽  
Kimberly A. Murza ◽  
Tami Cassel

Purpose The purpose of this study was to explore the perceptions of special education practitioners (i.e., speech-language pathologists, special educators, para-educators, and other related service providers) on their role as communication partners after participation in the Social Communication and Engagement Triad (Buckley et al., 2015 ) yearlong professional learning program. Method A qualitative approach using interviews and purposeful sampling was used. A total of 22 participants who completed participation in either Year 1 or Year 2 of the program were interviewed. Participants were speech-language pathologists, special educators, para-educators, and other related service providers. Using a grounded theory approach (Glaser & Strauss, 1967 ) to data analysis, open, axial, and selective coding procedures were followed. Results Three themes emerged from the data analysis and included engagement as the goal, role as a communication partner, and importance of collaboration. Conclusions Findings supported the notion that educators see the value of an integrative approach to service delivery, supporting students' social communication and engagement across the school day but also recognizing the challenges they face in making this a reality.


1989 ◽  
Vol 54 (3) ◽  
pp. 403-421 ◽  
Author(s):  
Beth M. Dalton ◽  
Jan L. Bedrosian

The communicative performance of 4 preoperational-level adolescents, using limited speech, gestures, and communication board techniques, was examined in a two-part investigation. In Part 1, each subject participated in an academic interaction with a teacher in a therapy room. Data were transcribed and coded for communication mode, function, and role. Two subjects were found to predominantly use the speech mode, while the remaining 2 predominantly used board and one other mode. The majority of productions consisted of responses to requests, and the initiator role was infrequently occupied. These findings were similar to those reported in previous investigations conducted in classroom settings. In Part 2, another examination of the communicative performance of these subjects was conducted in spontaneous interactions involving speaking and nonspeaking peers in a therapy room. Using the same data analysis procedures, gesture and speech modes predominated for 3 of the subjects in the nonspeaking peer interactions. The remaining subject exhibited minimal interaction. No consistent pattern of mode usage was exhibited across the speaking peer interactions. In the nonspeaking peer interactions, requests predominated. In contrast, a variety of communication functions was exhibited in the speaking peer interactions. Both the initiator and the maintainer roles were occupied in the majority of interactions. Pertinent variables and clinical implications are discussed.


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