Archives of Physical Medicine and Rehabilitation
Volume 90, Issue 6 , Pages 1055-1060, June 2009

Trunk Muscle Activation Patterns and Spine Kinematics When Using an Oscillating Blade: Influence of Different Postures and Blade Orientations

  • Daniel Sánchez-Zuriaga, MD, PhD

      Affiliations

    • Department of Anatomy and Human Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
    • ,
  • Francisco J. Vera-Garcia, PhD

      Affiliations

    • Area of Physical Education and Sport, Department of Health Psychology, Miguel Hernandez University of Elche, Elche, Alicante, Spain
    • ,
  • Janice M. Moreside, PT, MHK

      Affiliations

    • Spine Biomechanics Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
    • ,
  • Stuart M. McGill, PhD

      Affiliations

    • Spine Biomechanics Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
    • Corresponding Author InformationReprint requests to Stuart M. McGill, PhD, Dept of Kinesiology, 200 University Ave W, University of Waterloo, Waterloo, ON, Canada N2L 3G1

Abstract 

Sánchez-Zuriaga D, Vera-Garcia FJ, Moreside JM, McGill SM. Trunk muscle activation patterns and spine kinematics when using an oscillating blade: influence of different postures and blade orientations.

Objective

To compare trunk muscle activation patterns and trunk kinematics when using an oscillating blade in standing and unsupported sitting postures, and with different orientations of the blade.

Design

A cross-sectional survey of trunk muscle activities and lumbar motion.

Setting

Biomechanics research laboratory.

Participants

Healthy men (N=13).

Interventions

An oscillating blade was held with 2 hands and oscillated with vertical and horizontal orientations of blade. These exercises were performed both in an erect standing position and in an erect sitting position.

Main Outcome Measures

Surface electromyography from 14 trunk and 2 shoulder muscles, together with lumbar angular displacement in the 3 planes of motion, were measured while subjects used an oscillating blade at different performance variations. Electromyographic signals were normalized to isometric maximal voluntary contraction (MVC) amplitudes.

Results

With the exception of internal oblique and anterior deltoid for the horizontal condition, and erector spinae at L5 level for the vertical condition, the subject's posture had no effect on trunk muscular recruitment when using the oscillating blade. The vertical blade orientation resulted in higher amplitudes of spine rotation on the horizontal plane and produced the greatest activation levels of the internal oblique (47% MVC), pectoralis major (33% MVC), and external oblique (23% MVC). On the other hand, the horizontal orientation resulted in the greatest activation levels of erector spinae at T9 level (28% MVC), latissimus dorsi (26% MVC), and rectus abdominis (17% MVC).

Conclusions

Muscle activation and spine motion from using an oscillating blade were not affected by the standing or sitting posture of the subject. The choice of blade orientation was more important, because it defined the main group of muscles recruited during the exercise.

Key Words: Electromyography, Rehabilitation

Abbreviations: EMG, electromyography, EO, external oblique, ES, erector spinae, IO, internal oblique, LD, latissimus dorsi, MVC, maximal voluntary contraction, RA, rectus abdominis

 

 Supported by the Natural Science and Engineering Research Council, Canada.

 No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

PII: S0003-9993(09)00158-0

doi:10.1016/j.apmr.2008.12.015

Archives of Physical Medicine and Rehabilitation
Volume 90, Issue 6 , Pages 1055-1060, June 2009

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