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Abstract

A model of low-back injury is presented suggesting structural instability is a risk factor in occupation injury. The purpose of this research was to document the potential for spinal buckling as a function of asymmetric and sagittal trunk angle during lifting. A biomechanical model was developed to compute the Euler stability and determine the structural tolerance of the lumbar spine in work-related postures. When applied load and associated spinal compression exceeds the structural tolerance, i.e. buckling load, the spinal column fails. Analyses demonstrate the structural tolerance is often less than material tolerance estimates, particularly in flexed and asymmetric postures. Furthermore, the structural tolerance is reduced in sagittally flexed and asymmetric lifting postures. Hence, the relation between stability and trunk posture correlated with low-back disorder (LBD) risk factors. Results suggest musculoskeletal instability may help explain the relation between LBD risk and lifting posture.

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References

Cady

L.D.

Bischoff

D.P.

O'Connell

E.R.

Thomas

P.C.

Allan

J. H.

(1979). Strength and fitness and subsequent back injuries in firefighters J.Occup.Med. 21 (4), 269–272.

Chaffin

D. B.

Page

G. B.

(1994). Postural effects on biomechanical and psychophysical weight-lifting limits Ergonomics 37 (4), 663–676.

Cholewicki

McGill

S. M.

(1996). Mechanical stability on the in vivo lumbar spine: Implications for injury and chronic low back pain Clin. Biomech. 11 (1), 1–15.

Crisco

J. J.

Panjabi

M. M.

(1991). The intersegmental and multisegmental muscles of the lumbar spine: A biomechanical model comparing lateral stabilizing potential Spine 16 (7), 793–799.

Crisco

J. J.

Panjabi

M. M.

(1992a). Euler stability of the human ligamentous lumbar spine: Part I Theory Clin.Biomech. 7, 19–26.

Crisco

J.J.

Panjabi

M.M.

Yamamoto

Oxland

T. R.

(1992b). Euler stability of the human ligamentous lumbar spine. Part II Experiment Clin.Biomech. 7, 27–32.

Frymoyer

J. W.

Selby

D. K.

(1985). Segmental Instability. Rationale for treatment Spine 10 (3), 280–286.

Gardner-Morse

Stokes

I.A.F.

Laible

J. P.

(1995). Role of muscles in lumbar stability in maximum extension efforts J.Orthop.Res. 13 (5), 802–808.

Granata

K. P.

Marras

W. S.

(1993). An EMG-assisted model of loads on the lumbar spine during asymmetric trunk extensions J.Biomechanics 26 (12), 1429–1438.

10.

Granata

K. P.

Marras

W. S.

(1995). The influence of trunk muscle coactivity upon dynamic spinal loads Spine 20 (8), 913–919.

11.

Granata

K.P.

Marras

W.S.

Kirking

(1996) Influence of Experience on Lifting Kinematics and Spinal Loading. Proc.Am.Soc.Biomechanics.

12.

Herrin

G.A.

Jaraiedi

Anderson

C. K.

(1986). Prediction of overexertion injuries using biomechanical and psychophysical models Am.Ind.Hyg.Assoc.J. 47 (6), 322–330.

13.

Hutton

W. C.

Adams

M. A.

(1982). Can the spine be crushed in heavy lifting? Spine 7 (6), 586–590.

14.

Kirkaldy-Willis

W.H.

Farfan

(1982). Instability of the lumbar spine Clin.Orthop. 165, 110–123.

15.

Lavender

S.A.

Mirka

G.A.

Schoenmarklin

R.W.

Sommerich

C.M.

Sudhakar

L.R.

Marras

W. S.

(1989). The effects of preview and task symmetry on trunk muscle response to sudden loading Human Factors 31 (1), 101–115.

16.

Marras

W.S.

Lavender

S.A.

Leurgans

Fathallah

Allread

W.G.

Ferguson

S.A.

Rajulu

(1995). Biomechanical risk factors for occupationally related low back disorder risk Ergonomics 38 (2), 377–410.

17.

Marras

W. S.

Mirka

G. A.

(1992). A comprehensive evaluation of trunk response to asymmetric trunk motion Spine 17 (3), 318–326.

18.

McGill

S.M.

Santiguida

Stevens

(1993). Measurement of the trunk musculature from T5 to L5 using MRI scans of 15 young males corrected for muscle fiber orientation Clin.Biomech. 8, 171–178.

19.

Nichols

T. R.

Houk

J. C.

(1976). Improvement of linearity and regulation of stiffness that results from the actions of the stretch reflex J.Neurophysiol. 39, 119–142.

20.

NIOSH (1981). A Work Practices Guide for Manual Lifting Tech. Report No.81–122, U.S. Dept. of Health and Human Services (NIOSH), Cincinnati, Oh.

21.

Punnet

Fine

L.J.

Keyserling

W.M.

Herrin

G.D.

Chaffin

D. B.

(1991). Back disorders and non-neutral trunk postures of automobile assembly workers Scand J. Work Envir.Health. 17, 337–346.

22.

Wilder

D.G.

Pope

M.H.

Frymoyer

J. W.

(1988). The biomechanics of lumbar disc herniation and the effect of overload and instability J Spinal Disorders 1 (1), 16–32.

LBD Risk Factors and the Structural Stability Tolerance of the Lumbar Spine

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