title: Muscle coactivation: a generalized or localized motor control strategy?
abstract: BACKGROUND
  We examined generalized versus joint-specific influences on muscle coactivation.
  
  
  METHODS
  Muscle coactivation was assessed during maximal isometric and isokinetic knee and elbow joint extension moments in 48 healthy subjects (27 men). Local (joint-specific) and generalized (person-specific) contributions were examined using a combination of statistical tests, including regression with generalized estimating equations (GEEs), exploratory factor analysis, and cluster analysis.
  
  
  RESULTS
  GEEs produced similar significant coefficients for gender and joint; contraction type and test condition (angle or velocity) were not significant. Factor analysis indicated 2 joint-based factors, and cluster analysis indicated 2 groups of individuals, those with and without elevated coactivation at the knee and elbow. Women exhibited greater coactivation at both joints, but no consistent influences of angle or velocity were observed at either joint.
  
  
  CONCLUSIONS
  Muscle coactivation is a neuromuscular control response determined by local, joint-specific, and generalized, individual-specific influences.
authors.affiliation: Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, 1-252 Medical Education Building, University of Iowa, Iowa City, Iowa, 52242, USA; Virtual Soldier Research, Center for Computer-Aided Design, College of Engineering, University of Iowa, Iowa City, Iowa.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Frey-Law
authors.forename: Keith G
authors.initials: KG
authors.lastname: Avin
mesh_terms: D000328:Adult; D004550:Elbow / Q000502:physiology*; D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D052580:Muscle Stretching Exercises / Q000295:instrumentation / Q000379:methods; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012737:Sex Factors; D055815:Young Adult
keywords: EMG; elbow; knee; motor control; muscle cocontraction
references.citation: J Neurophysiol. 1987 Sep;58(3):525-42
references.pmid: 3655881
references.citation: Clin Biomech (Bristol, Avon). 2005 Jan;20(1):97-104
references.pmid: 15567543
references.citation: Exp Brain Res. 2007 Jan;176(3):448-64
references.pmid: 16896977
references.citation: Muscle Nerve. 2011 Nov;44(5):838-9
references.pmid: 22006702
references.citation: Eur J Appl Physiol Occup Physiol. 1999 May;79(6):504-11
references.pmid: 10344460
references.citation: Scand J Med Sci Sports. 2000 Apr;10(2):58-67
references.pmid: 10755275
references.citation: J Electromyogr Kinesiol. 2009 Jun;19(3):449-58
references.pmid: 18093843
references.citation: Am J Sports Med. 1988 Mar-Apr;16(2):113-22
references.pmid: 3377094
references.citation: J Appl Biomech. 2012 Dec;28(6):726-37
references.pmid: 22813601
references.citation: Mov Disord. 1994 Sep;9(5):493-507
references.pmid: 7990845
references.citation: Brain. 1998 May;121 ( Pt 5):801-14
references.pmid: 9619186
references.citation: J Electromyogr Kinesiol. 1996 Dec;6(4):235-45
references.pmid: 20719680
references.citation: Eur J Appl Physiol Occup Physiol. 1997;76(3):253-9
references.pmid: 9286605
references.citation: Am J Sports Med. 1987 May-Jun;15(3):207-13
references.pmid: 3618871
references.citation: J Electromyogr Kinesiol. 2006 Jun;16(3):273-80
references.pmid: 16144766
references.citation: J Appl Physiol (1985). 1993 Jan;74(1):170-5
references.pmid: 8444689
references.citation: Med Sci Sports Exerc. 1998 Nov;30(11):1616-23
references.pmid: 9813875
references.citation: Arthritis Rheum. 2007 Apr 15;57(3):389-97
references.pmid: 17394224
references.citation: Knee Surg Sports Traumatol Arthrosc. 2009 Aug;17(8):946-55
references.pmid: 19444431
references.citation: Electromyogr Clin Neurophysiol. 1985 Mar-Apr;25(2-3):135-49
references.pmid: 3987606
references.citation: Eur J Appl Physiol Occup Physiol. 1990;61(5-6):453-60
references.pmid: 2079066
references.citation: Knee Surg Sports Traumatol Arthrosc. 2001;9(2):62-71
references.pmid: 11354855
references.citation: J Electromyogr Kinesiol. 1997 Sep;7(3):179-86
references.pmid: 20719703
references.citation: J Appl Physiol (1985). 2000 Jul;89(1):61-71
references.pmid: 10904036
references.citation: Clin Biomech (Bristol, Avon). 1998 Apr;13(3):153-162
references.pmid: 11415783
references.citation: J Electromyogr Kinesiol. 2003 Jun;13(3):229-38
references.pmid: 12706603
references.citation: Adv Neurol. 1983;39:347-72
references.pmid: 6419553
references.citation: J Electromyogr Kinesiol. 2012 Apr;22(2):325-6
references.pmid: 22155059
references.citation: J Neurophysiol. 2003 May;89(5):2396-405
references.pmid: 12611935
references.citation: Muscle Nerve. 2006 Feb;33(2):191-9
references.pmid: 16307438
references.citation: J Electromyogr Kinesiol. 2011 Feb;21(1):1-12
references.pmid: 20869882
references.citation: J Electromyogr Kinesiol. 2009 Jun;19(3):459-66
references.pmid: 18249140
references.citation: J Electromyogr Kinesiol. 2009 Dec;19(6):1085-91
references.pmid: 19081734
references.citation: Eur J Appl Physiol. 2004 Mar;91(2-3):349-52
references.pmid: 14648124
references.citation: J Neurophysiol. 1991 Feb;65(2):330-51
references.pmid: 2016644
references.citation: Med Sci Sports Exerc. 1995 Jun;27(6):805-8
references.pmid: 7658940
references.citation: Am J Sports Med. 1991 May-Jun;19(3):305-16
references.pmid: 1867339
references.citation: Am J Sports Med. 1990 Mar-Apr;18(2):182-7
references.pmid: 2343987
references.citation: Am J Phys Med. 1984 Dec;63(6):289-97
references.pmid: 6507602
references.citation: J Electromyogr Kinesiol. 1991 Sep;1(3):199-208
references.pmid: 20870510
references.citation: J Biomech. 2011 Jan 4;44(1):202-5
references.pmid: 20869716
references.citation: Methods Inf Med. 2004;43(1):30-5
references.pmid: 15026832
references.citation: Phys Ther. 2007 Nov;87(11):1422-32
references.pmid: 17785376
references.citation: J Electromyogr Kinesiol. 1994;4(1):15-26
references.pmid: 20870543
references.citation: J Biomech. 1995 May;28(5):513-25
references.pmid: 7775488
references.citation: Sports Med. 1998 Jan;25(1):37-62
references.pmid: 9458526
references.citation: Multivariate Behav Res. 1966 Apr 1;1(2):245-76
references.pmid: 26828106
references.citation: Pflugers Arch. 2003 Sep;446(6):735-41
references.pmid: 12851821
references.citation: Arch Phys Med Rehabil. 2007 Aug;88(8):1022-9
references.pmid: 17678665
references.citation: Exp Neurol. 1988 Jun;100(3):470-7
references.pmid: 3366200