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Review
. 2007 Mar;22(3):266-74.
doi: 10.1016/j.clinbiomech.2006.11.011. Epub 2007 Jan 8.

Spine stability: the six blind men and the elephant

N Peter Reeves  1 , Kumpati S Narendra, Jacek Cholewicki
Affiliations
Review

Spine stability: the six blind men and the elephant

N Peter Reeves et al. Clin Biomech (Bristol). 2007 Mar.

Abstract

Stability is one of the most fundamental concepts to characterize and evaluate any system. This term is often ambiguously used in spinal biomechanics. Confusion arises when the static analyses of stability are used to study dynamic systems such as the spine. Therefore, the purpose of this paper is to establish a common ground of understanding, using standard, well-defined terms to frame future discussions regarding spine dynamics, stability, and injury. A qualitative definition of stability, applicable to dynamic systems, is presented. Additional terms, such as robustness (which is often confused with stability) and performance are also defined. The importance of feedback control in maintaining stability is discussed. Finally, these concepts are applied to understand low back pain and risk of injury.

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Figures

Figure 1a–b
Figure 1a–b
Stability of a ball.
Figure 2a–b
Figure 2a–b
Robustness to perturbation.
Figure 3a–b
Figure 3a–b
Robustness to change in system’s parameters.
Figure 4a–b
Figure 4a–b
Feedback control of a spine.
Figure 4a–b
Figure 4a–b
Feedback control of a spine.
Figure 5a–b
Figure 5a–b
Response to perturbations in the spine.
Figure 6
Figure 6
Components of the spine feedback controller.
Figure 7
Figure 7
The CNS can compensate for a reduction in intervertebral stiffness by increasing trunk muscle co-activation. The passive stiffness of the intervertebral joint is represented by the torsional spring at the base of the inverted pendulum.
See this image and copyright information in PMC

Comment in

References

    1. Bergmark A. Mechanical Stability of the Human Lumbar Spine. Department of Solid Mechanics; Lund University: 1987.
    1. Bergmark A. Stability of the lumbar spine. A study in mechanical engineering. Acta Orthop Scand Suppl. 1989;230:1–54. - PubMed
    1. Bjorksten M, Jonsson B. Endurance limit of force in long-term intermittent static contractions. Scand J Work Environ Health. 1977;3:23–7. - PubMed
    1. Burke RE, Levine DN, Tsairis P, Zajac FE. Physiological types and histochemical profiles in motor units of the cat gastrocnemius. J Physiol. 1973;234:723–48. - PMC - PubMed
    1. Buxton DF, Peck D. Neuromuscular spindles relative to joint complexities. Clinical anatomy. 1989;2:211–24.

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