A musculoskeletal shoulder model based on pseudo-inverse and null-space optimization

Terrier, Alexandre; Aeberhard, Martin; Michellod, Y.; Müllhaupt, Ph.; Gillet, Denis; Farron, Alain; Pioletti, Dominique P.

doi:10.1016/j.medengphy.2010.07.006

Cited by 35 publications

(40 citation statements)

References 43 publications

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“…The optimisation method minimises muscle stresses and is therefore referred to as the stress-based method in the following. The work was realised on a 3D model of the glenohumeral joint (Terrier et al 2007(Terrier et al , 2010(Terrier et al , 2013, which is used to analyse issues related to total shoulder arthroplasty. The model has the ability to predict glenohumeral stability through the evaluation of humeral head translation.…”

Section: Introductionmentioning

confidence: 99%

Comparison of an EMG-based and a stress-based method to predict shoulder muscle forces

Engelhardt

Camine

Ingram

et al. 2014

Computer Methods in Biomechanics and Biomedical Engineering

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The estimation of muscle forces in musculoskeletal shoulder models is still controversial. Two different methods are widely used to solve the indeterminacy of the system: electromyography (EMG)-based methods and stress-based methods. The goal of this work was to evaluate the influence of these two methods on the prediction of muscle forces, glenohumeral load and joint stability after total shoulder arthroplasty. An EMG-based and a stress-based method were implemented into the same musculoskeletal shoulder model. The model replicated the glenohumeral joint after total shoulder arthroplasty. It contained the scapula, the humerus, the joint prosthesis, the rotator cuff muscles supraspinatus, subscapularis and infraspinatus and the middle, anterior and posterior deltoid muscles. A movement of abduction was simulated in the plane of the scapula. The EMG-based method replicated muscular activity of experimentally measured EMG. The stress-based method minimised a cost function based on muscle stresses. We compared muscle forces, joint reaction force, articular contact pressure and translation of the humeral head. The stress-based method predicted a lower force of the rotator cuff muscles. This was partly counter-balanced by a higher force of the middle part of the deltoid muscle. As a consequence, the stress-based method predicted a lower joint load (16% reduced) and a higher superior -inferior translation of the humeral head (increased by 1.2 mm). The EMG-based method has the advantage of replicating the observed cocontraction of stabilising muscles of the rotator cuff. This method is, however, limited to available EMG measurements. The stress-based method has thus an advantage of flexibility, but may overestimate glenohumeral subluxation.

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Section: Introductionmentioning

confidence: 99%

Comparison of an EMG-based and a stress-based method to predict shoulder muscle forces

Engelhardt

Camine

Ingram

et al. 2014

Computer Methods in Biomechanics and Biomedical Engineering

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“…This problem is particularly present for the shoulder, which has a wide range of motion, and many muscles. As for other joints, three techniques are used: 1) group muscles to suppress the indeterminacy (Inman et al, 1944), 2) use inverse dynamics coupled with optimization of a cost function (Charlton and Johnson, 2006;Dickerson et al, 2007;Favre et al, 2005;Holzbaur et al, 2005;Karlsson and Peterson, 1992;Terrier et al, 2010;van der Helm, 1994), or 3) use forward dynamics with electromyography (EMG) measurements as input (Langenderfer et al, 2005;Laursen et al, 1998;Terrier et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Importance of the subscapularis muscle after total shoulder arthroplasty

Terrier

Larrea

Camine

et al. 2013

Clinical Biomechanics

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Background: The rotator cuff muscles are the main stabilizer of the glenohumeral joint. After total shoulder arthroplasty using anterior approaches, a dysfunction of the subscapularis muscle has been reported. In the present paper we tested the hypothesis that a deficient subscapularis following total shoulder arthroplasty can induce joint instability. Methods: To test this hypothesis we have developed an EMG-driven musculoskeletal model of the glenohumeral joint. The model was based on an algorithm that minimizes the difference between measured and predicted muscular activities, while satisfying the mechanical equilibrium of the glenohumeral joint. A movement of abduction in the scapular plane was simulated. We compared a normal and deficient subscapularis. Muscle forces, joint force, contact pattern and humeral head translation were evaluated. Findings: To satisfy the mechanical equilibrium, a deficient subscapularis induced a decrease of the force of the infraspinatus muscle. This force decrease was balanced by an increase of the supraspinatus and middle deltoid. As a consequence, the deficient subscapularis induced an upward migration of the humeral head, an eccentric contact pattern and higher stress within the cement. Interpretation: These results confirm the importance of the suscapularis for the long-term stability of total shoulder arthroplasty.

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“…The null-space method was used both because it has shown promising results (Aeberhard et al 2009;Terrier et al 2010) and because it helped to pinpoint the nature of the unfeasibility observed in Ingram et al (2012) due to its direct use of the map (13) to construct the solution.…”

Section: Discussionmentioning

confidence: 99%

“…A detailed presentation of this re-parameterisation is given in Aeberhard et al (2009) andTerrier et al (2010).…”

Section: Null-space Optimisationmentioning

confidence: 99%

Muscle moment-arms: a key element in muscle-force estimation

Ingram

Engelhardt

Farron

et al. 2013

Computer Methods in Biomechanics and Biomedical Engineering

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A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to incorrect moment-arms if used inappropriately due to its dependency on the choice of joint coordinates. The definition of moment-arms, and the presented construction method, apply to musculoskeletal models in which the bones are modelled as rigid bodies, the joints are modelled as ideal mechanical joints and the muscles are modelled as massless, frictionless cables wrapping over the bony protrusions, approximated using geometric surfaces. In this context, the definition is independent of any coordinate choice. It is then used to solve a muscle-force estimation problem for a simple 2D conceptual model and compared with an incorrect application of the tendon excursion method. The relative errors between the two solutions vary between 0% and 100%.

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A musculoskeletal shoulder model based on pseudo-inverse and null-space optimization

Cited by 35 publications

References 43 publications

Comparison of an EMG-based and a stress-based method to predict shoulder muscle forces

Comparison of an EMG-based and a stress-based method to predict shoulder muscle forces

Importance of the subscapularis muscle after total shoulder arthroplasty

Muscle moment-arms: a key element in muscle-force estimation

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