Do Exercise Balls Provide a Training Advantage for Trunk Extensor Exercises? A Biomechanical Evaluation
Received 30 June 2005; received in revised form 22 August 2005
Abstract
Objective
Only a few abdominal muscle exercises have been quantitatively evaluated on both a mat and exercise ball, but the benefits reported for the ball have been equivocally applied to all exercises. The purpose of this study is to evaluate differences in the biological response of muscle activation, lumbar spine posture, and loading variables for extensor exercises performed on 2 surfaces.
Methods
Bilateral muscle activation was recorded from 7 sites (rectus abdominis, external/internal obliques, latissimus dorsi, thoracic/lumbar erector spinae, and multifidus) on 8 subjects. Three-dimensional lumbar spine postures and upper body kinematics were recorded while the participants performed the exercises. An electromyography-driven model was used to calculate spinal loading.
Results
Cocontraction of trunk flexor and extensor muscles was reduced by up to 30% for the extension exercises when performed on the ball. Peak muscle activation remained unchanged or decreased, and spinal loading (compression and anterior-posterior shear) decreased when the extension exercises were performed on the ball. The lumbar spine postures attained during the exercises did not differ between surfaces.
Conclusions
The assumption that the use of an exercise ball will always create a greater challenge for the musculoskeletal system was not supported by the findings of this study. Likewise, in a healthy, young population, there does not appear to be any training advantage to performing extensor exercises on a ball versus a mat. However, in a rehabilitation scenario, these exercises performed on a ball could reduce low back loading and hence reduce the potential for reinjury.
aPhD Candidate, Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Canada
bMSc Candidate, Faculty of Kinesiology, University of New Brunswick, Fredericton, New Brunswick, Canada
cPhD Candidate, Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Canada
dAssociate Professor, Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
Submit requests for reprints to: Dr. Jack P. Callaghan, Associate Professor, Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
ABSTRACT