title: Stochastic modelling of muscle recruitment during activity.
abstract: Muscle forces can be selected from a space of muscle recruitment strategies that produce stable motion and variable muscle and joint forces. However, current optimization methods provide only a single muscle recruitment strategy. We modelled the spectrum of muscle recruitment strategies while walking. The equilibrium equations at the joints, muscle constraints, static optimization solutions and 15-channel electromyography (EMG) recordings for seven walking cycles were taken from earlier studies. The spectrum of muscle forces was calculated using Bayesian statistics and Markov chain Monte Carlo (MCMC) methods, whereas EMG-driven muscle forces were calculated using EMG-driven modelling. We calculated the differences between the spectrum and EMG-driven muscle force for 1-15 input EMGs, and we identified the muscle strategy that best matched the recorded EMG pattern. The best-fit strategy, static optimization solution and EMG-driven force data were compared using correlation analysis. Possible and plausible muscle forces were defined as within physiological boundaries and within EMG boundaries. Possible muscle and joint forces were calculated by constraining the muscle forces between zero and the peak muscle force. Plausible muscle forces were constrained within six selected EMG boundaries. The spectrum to EMG-driven force difference increased from 40 to 108 N for 1-15 EMG inputs. The best-fit muscle strategy better described the EMG-driven pattern (R (2) = 0.94; RMSE = 19 N) than the static optimization solution (R (2) = 0.38; RMSE = 61 N). Possible forces for 27 of 34 muscles varied between zero and the peak muscle force, inducing a peak hip force of 11.3 body-weights. Plausible muscle forces closely matched the selected EMG patterns; no effect of the EMG constraint was observed on the remaining muscle force ranges. The model can be used to study alternative muscle recruitment strategies in both physiological and pathophysiological neuromotor conditions.
authors.affiliation: Medical Device Research Institute, School of Computer Science, Engineering and Mathematics , Flinders University , Tonsley, South Australia 5042 , Australia ; North West Academic Centre , The University of Melbourne , St Albans, Victoria 3021 , Australia.
authors.forename: Saulo
authors.identifier: 0000-0002-0012-8122
authors.initials: S
authors.lastname: Martelli
authors.affiliation: Department of Mathematics , Applied Mathematics, and Statistics, Case Western Reserve University , Cleveland, OH 44106-7058 , USA.
authors.forename: Daniela
authors.initials: D
authors.lastname: Calvetti
authors.affiliation: Department of Mathematics , Applied Mathematics, and Statistics, Case Western Reserve University , Cleveland, OH 44106-7058 , USA.
authors.forename: Erkki
authors.initials: E
authors.lastname: Somersalo
authors.affiliation: Department of Mechanical Engineering and INSIGNEO Institute for in silico Medicine , University of Sheffield , Sheffield S1 3JD , UK.
authors.forename: Marco
authors.identifier: 0000-0002-2293-1530
authors.initials: M
authors.lastname: Viceconti
keywords: electromyography; human locomotion; muscle synergy; neuromusculoskeletal modelling; statistic EMG-driven muscle force; stochastic muscle recruitment
references.citation: J Biomech. 1989;22(8-9):885-93
references.pmid: 2613724
references.citation: J Biomech. 2009 May 11;42(7):898-905
references.pmid: 19268945
references.citation: Nature. 2004 Jan 15;427(6971):244-7
references.pmid: 14724638
references.citation: Clin Biomech (Bristol, Avon). 2014 Sep;29(8):869-76
references.pmid: 25156184
references.citation: J Bone Miner Res. 2014 Jun;29(6):1337-45
references.pmid: 24293094
references.citation: Gait Posture. 1999 Dec;10(3):211-22
references.pmid: 10567753
references.citation: Gait Posture. 2007 Oct;26(4):560-71
references.pmid: 17291764
references.citation: Clin Biomech (Bristol, Avon). 1998 Apr;13(3):204-215
references.pmid: 11415789
references.citation: J Biomech. 1992 Mar;25(3):223-34
references.pmid: 1564058
references.citation: Trends Cogn Sci. 2006 Jul;10(7):319-26
references.pmid: 16807063
references.citation: J Theor Biol. 2009 Aug 21;259(4):695-700
references.pmid: 19406130
references.citation: Langenbecks Arch Surg. 2004 Feb;389(1):53-9
references.pmid: 14625775
references.citation: IEEE Trans Biomed Eng. 2003 Mar;50(3):316-23
references.pmid: 12669988
references.citation: J Biomech. 1995 Mar;28(3):321-31
references.pmid: 7730390
references.citation: Clin Orthop Relat Res. 2009 Apr;467(4):1074-82
references.pmid: 18972175
references.citation: Comput Biol Med. 2009 Dec;39(12 ):1083-8
references.pmid: 19818436
references.citation: J Biomech Eng. 2003 Feb;125(1):70-7
references.pmid: 12661198
references.citation: J Biomech. 2003 Mar;36(3):321-8
references.pmid: 12594980
references.citation: Clin Biomech (Bristol, Avon). 2012 Mar;27(3):273-80
references.pmid: 22015265
references.citation: PLoS One. 2012;7(12):e52618
references.pmid: 23300725
references.citation: Hum Mov Sci. 2012 Apr;31(2):429-47
references.pmid: 22244106
references.citation: J Biomech. 2010 Jan 19;43(2):364-9
references.pmid: 19840881
references.citation: Gait Posture. 2008 Oct;28(3):358-65
references.pmid: 18571416
references.citation: J Biomech. 2007;40(8):1776-85
references.pmid: 17070817
references.citation: Comput Aided Surg. 2000;5(2):108-19
references.pmid: 10862133
references.citation: Gait Posture. 2008 May;27(4):578-88
references.pmid: 17889542
references.citation: J Neurophysiol. 2005 Jul;94(1):395-9
references.pmid: 15716368
references.citation: J Biomech. 2003 Jun;36(6):765-76
references.pmid: 12742444
references.citation: Biol Cybern. 2012 Dec;106(11-12):757-65
references.pmid: 22895830
references.citation: J Neurophysiol. 2004 Nov;92(5):3161-5
references.pmid: 15190091
references.citation: J Biomech. 2006;39(4):758-65
references.pmid: 16439246
references.citation: Clin Biomech (Bristol, Avon). 2008 Dec;23(10):1279-86
references.pmid: 18790553
references.citation: J Biomech. 2012 Feb 2;45(3):421-6
references.pmid: 22204893
references.citation: J Biomech. 1998 Jan;31(1):77-80
references.pmid: 9596541
references.citation: J Biomech. 2011 Jun 3;44(9):1716-21
references.pmid: 21497815
references.citation: J Physiol Sci. 2008 Dec;58(7):441-6
references.pmid: 18928640
references.citation: J Biomech. 1981;14(11):793-801
references.pmid: 7334039
references.citation: IEEE Trans Biomed Eng. 2007 Nov;54(11):1940-50
references.pmid: 18018689
references.citation: Proc Inst Mech Eng H. 2012 Feb;226(2):161-9
references.pmid: 22468467
references.citation: IEEE Trans Biomed Eng. 2005 Oct;52(10 ):1756-63
references.pmid: 16235661
references.citation: Comput Methods Programs Biomed. 2010 Feb;97(2):151-67
references.pmid: 19748150
references.citation: J Appl Biomech. 2004 Nov;20(4):367-95
references.pmid: 16467928
references.citation: Biol Cybern. 2008 Dec;99(6):503-16
references.pmid: 18985380
references.citation: IEEE Trans Biomed Eng. 1990 Aug;37(8):757-67
references.pmid: 2210784
references.citation: J Biomech. 2013 Aug 9;46(12):2097-100
references.pmid: 23791083
references.citation: Phys Ther. 2006 Aug;86(8):1151-60
references.pmid: 16879049
references.citation: Crit Rev Biomed Eng. 1989;17(4):359-411
references.pmid: 2676342
references.citation: J Biomech. 2014 Jun 3;47(8):1784-91
references.pmid: 24746018