Abdominal and erector spinae muscle activity during gait: the use of cluster analysis to identify patterns of activity


      Objective. To describe patterns of muscle activation during gait in selected abdominal and lumbar muscles using cluster analysis.
      Participants. A sample of convenience of 38 healthy adult volunteers.
      Outcome measures. Electromyographic activity from the right internal and external obliques, rectus abdominis and lumbar erector spinae were recorded, and the root mean square values for each muscle were calculated throughout the stride in 5% epochs. These values were normalised to maximum effort isometric muscle contractions. Cluster analysis was used to identify groups of subjects with similar patterns of activity and activation levels.
      Results. Cluster analysis identified two patterns of activity for the internal oblique, external oblique and rectus abdominis muscles. In the lumbar erector spinae, three patterns of activity were observed. In most instances, the patterns observed for each muscle differed in the magnitude of the activation levels. In rectus abdominis and external oblique muscles, the majority of subjects had low levels of activity (<5.0% of a maximum voluntary contraction) that were relatively constant throughout the stride cycle. In the internal oblique and the erector spinae muscles, more distinct bursts of activity were observed, most often close to foot-strike. The different algorithms used for the cluster analysis yielded similar results and a discriminant function analysis provided further evidence to support the patterns observed.
      Conclusions. Cluster analysis was useful in grouping subjects who had similar patterns of muscle activity. It provided evidence that there were subgroups that might otherwise not be observed if a group ensemble was presented as the `norm' for any particular muscle's role during gait.Relevance
      The identification of common variations in muscle activity may prove valuable in identifying individuals with electromyographic patterns that might influence their chances of sustaining injury. Alternatively, clusters may provide important information related to muscle activity in those that do well or otherwise after a particular injury.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Clinical Biomechanics
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Perry J.
        Gait analysis: normal and pathological function. Thorofare, SLACK Inc, New Jersey1992: 136-137
        • Saunders J.
        • Inman V.
        • Eberhart H.
        The major determinants in normal and pathological gait.
        J. Bone Joint Surg. 1953; 35A: 543-548
        • Tang P.
        • Woollacott M.H.
        • Chong R.K.Y.
        Control of reactive balance adjustments in perturbed human walking: roles of proximal and distal postural muscle activity.
        Exp. Brain Res. 1998; 119: 141-152
        • Smeathers J.
        Shocking news about discs.
        Current Orthop. 1994; 8: 45-48
        • Carlson H.A.
        • Thorstensson A.
        • Nilsson J.
        Lumbar back muscle activity during locomotion: effects of voluntary modifications of normal trunk movements.
        Acta Physiol. Scand. 1988; 133: 343-353
        • Murray M.
        • Mollinger L.
        • Gardner G.
        • Sepic S.
        Kinematic and EMG patterns during slow, free, and fast walking.
        J. Orthop. Res. 1984; 2: 272-280
        • Murray M.P.
        • Spurr G.B.
        • Sepic S.B.
        • Gardner G.M.
        • Mollinger L.A.
        Treadmill vs floor walking: kinematics, electromyogram, and heart rate.
        J. Appl. Physiol. 1985; 59: 87-91
        • Thorstensson A.
        • Carlson H.
        • Zomlefer M.R.
        • Nilsson J.
        Lumbar back muscle activity in relation to trunk movements during locomotion in man.
        Acta Physiol. Scand. 1982; 116: 13-20
        • Thorstensson A.
        • Nilsson J.
        • Carlson H.
        • Zomlefer M.R.
        Trunk movements in human locomotion.
        Acta Physiol. Scand. 1984; 121: 9-22
        • Waters R.L.
        • Morris J.M.
        Electrical activity of muscles of the trunk during walking.
        J. Anat. 1972; 111: 191-199
        • Callaghan J.
        • Patla A.
        • McGill S.
        Low back three dimensional joint forces, kinematics, and kinetics during walking.
        Clin. Biomech. 1999; 14: 203-216
        • Dofferhof A.S.M.
        • Vink P.
        The stabilising function of the mm. iliocostales and the mm. multifidi during walking.
        J. Anat. 1985; 140: 329-336
        • Krebs D.E.
        • Wong D.
        • Jevsevar D.
        • Riley P.O.
        • Hodge W.A.
        Trunk kinematics during locomotor activities.
        Phys. Ther. 1992; 72: 505-514
        • Sheffield F.
        Electromyographic study of abdominal muscles in walking and other movements.
        Am. J. Phys. Med. 1962; 41: 142
        • Grillner S.
        • Nilsson J.
        • Thorstensson A.
        Intra-abdominal pressure changes during natural movements in man.
        Acta Physiol. Scand. 1978; 103: 275-283
        • Yang J.
        • Winter D.
        Electromyographic amplitude normalization methods: improving their sensitivity as diagnostic tools in gait analysis.
        Arch. Phys. Med. Rehabil. 1984; 65: 517-521
        • Yang J.F.
        • Winter D.A.
        Surface EMG profiles during different walking cadences in humans.
        Electroencephalogr. Clin. Neurophysiol. 1985; 60: 485-491
        • Winter D.A.
        • Patla A.E.
        • Frank J.S.
        • Walt S.E.
        Biomechanical walking pattern changes in the fit and healthy elderly.
        Phys. Ther. 1990; 70: 340-347
        • Chen J.J.
        • Shiavi R.
        Temporal feature extraction and clustering analysis of electromyographic linear envelopes in gait studies.
        IEEE Trans. Biomed. Eng. 1990; 37: 295-302
        • Hair J.
        • Anderson R.E.
        • Tatham R.L.
        Multivariate data analysis with readings. 2nd ed. Macmillan, New York1990: 293-348
        • Shiavi R.
        • Griffen P.
        Representing and clustering electromyographic gait patterns with multivariate techniques.
        Med. Biol. Eng. Comput. 1981; 19: 605-611
        • Miller R.A.
        • Thaut M.H.
        • McIntosh G.C.
        • Rice R.R.
        Components of EMG symmetry and variability in parkinsonian and healthy elderly gait.
        Electroencephalogr. Clin. Neurophysiol. 1996; 101: 1-7
        • Ng J.
        • Kippers V.
        • Richardson C.
        Muscle fibre orientation of abdominal muscles and suggested surface EMG electrode positions.
        Electromyogr. Clin. Neurophysiol. 1998; 38: 51-58
        • DeFoa J.L.
        • Forrest W.
        • Biedermann H.
        Muscle fibre direction of Longissimus, Iliocostalis and Multifidus: landmark-derived reference lines.
        J. Anat. 1989; 163: 243-247
        • Soderberg G.
        • Knutson L.
        A guide for use and interpretation of kinesiologic electromyographic data.
        Phys. Ther. 2000; 80: 485-498
        • McGill S.
        Electromyographic activity of the abdominal and low back musculature during the generation of isometric and dynamic axial trunk torque: implications for lumbar mechanics.
        J. Orthop. Res. 1991; 9: 91-103
        • Field H.S.
        • Schoenfeldt L.F.
        Ward and Hook revisited: a two-part procedure for overcoming a deficiency in the grouping of two persons.
        Educ. Psychol. Meas. 1975; : 171-173
        • Johnson R.A.
        • Wichern D.W.
        Applied multivariate statistical analysis. 3rd ed. Prentice-Hall, Englewood Cliffs, NJ1992
        • Morris R.
        • Blashfield R.
        • Satz P.
        Neuropsychology and cluster analysis: potentials and problems.
        J. Clin. Neuropsychol. 1981; 3: 79-99
        • Winter D.A.
        • Yack H.J.
        EMG profiles during normal human walking: stride-to-stride and inter-subject variability.
        Electroenceph. Clin. Neurophysiol. 1987; 67: 402-411
        • Shiavi R.
        Electromyographic patterns in normal adult locomotion.
        in: Smidt G.L. Gait in rehabilitation. Churchill Livingstone, New York1990: 97-119