Muscle co-contraction in an upper limb musculoskeletal model: EMG-assisted vs. standard load-sharing. Issue 2 (25th January 2021)

• Record Type: Journal Article
• Authors: Sarshari, Ehsan; Mancuso, Matteo; Terrier, Alexandre; Farron, Alain; Mullhaupt, Philippe; Pioletti, Dominique
• Is Part Of: Computer methods in biomechanics and biomedical engineering. Volume 24:Issue 2(2021)
• Page Start: 137
• Page End: 150
• Publication Date: 2021-01-25
• Subjects: Muscle over-actuations -- inverse dynamics -- muscle force estimations -- antagonistic muscle co-contractions -- Hill-type models; Biomechanics -- Data processing -- Periodicals; Biomedical engineering -- Periodicals; Biomechanics -- Periodicals; Biomedical Engineering -- methods -- Periodicals; Computing Methodologies -- Periodicals; 612.7
• DOI: 10.1080/10255842.2020.1814755
• Languages: English
• ISSNs: 1025-5842

Abstract

Abstract: Estimation of muscle forces in over-actuated musculoskeletal models involves optimal distributions of net joint moments among muscles by a standard load-sharing scheme (SLS). Given that co-contractions of antagonistic muscles are counterproductive in the net joints moments, SLS might underestimate the co-contractions. Muscle co-contractions play crucial roles in stability of the glenohumeral (GH) joint. The aim of this study was to improve estimations of muscle co-contractions by incorporating electromyography (EMG) data into an upper limb musculoskeletal model. To this end, the model SLS was modified to develop an EMG-assisted load-sharing scheme (EALS). EMG of fifteen muscles were measured during arm flexion and abduction on a healthy subject and fed into the model. EALS was compared to SLS in terms of muscle forces, GH joint reaction force, and a stability ratio defined to quantify the GH joint stability. The results confirmed that EALS estimated higher muscle co-contractions compared to the SLS (e.g., above 50 N higher forces for both triceps long and biceps long during arm flexion).