Dynamic forces acting on the lumbar spine during manual handling. Can they be estimated using electromyographic techniques alone?

P. Dolan, I Kingma, J van Dieen, M P de Looze, H M Toussaint, C.T.M. Baten, M.A. Adams

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

STUDY DESIGN: Compressive loading of the lumbar spine was analyzed using electromyographic, movement analysis, and force-plate techniques.

OBJECTIVES: To evaluate the inertial forces that cannot be detected by electromyographic techniques alone.

SUMMARY OF BACKGROUND DATA: Links between back pain and manual labor have stimulated attempts to measure spine compressive loading. However, direct measurements of intradiscal pressure are too invasive, and force plates too cumbersome for use in the workplace. Electromyographic techniques are noninvasive and portable, but ignore certain inertial forces.

METHODS: Eight men lifted boxes weighing 6.7 and 15.7 kg from the ground, while joint moments acting about L5-S1 were quantified 1) by using a linked-segment model to analyze data from Kistler force plates and a Vicon movement-analysis system, and 2) by measuring the electromyographic activity of the erector spinae muscles, correcting it for contraction speed and comparing it to moment generation during static contractions. The linked-segment model was used to calculate the "axial thrust," defined as the component of the L5-S1 reaction force that acts along the axis of the spine and that is unrelated to trunk muscle activity or static body weight.

RESULTS: Peak extensor moments predicted by the two techniques were similar and equivalent to spinal compressive forces of 2.9-4.8 kN. The axial thrust "hidden" from the electromyographic technique was negligible during slow lifts, and remained below 4% of peak spinal compression even during fast heavy lifts. Peak axial thrust was proportional to the peak vertical ground reaction (R2 = 0.74).

CONCLUSIONS: Electromyographic techniques can measure dynamic spinal loading, but additional force-plate data would improve accuracy slightly during lifts requiring a vigorous upward thrust from the legs.

LanguageEnglish
Pages698-703
Number of pages6
JournalSpine
Volume24
Issue number7
Publication statusPublished - 1 Apr 1999

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Spine
Muscles
Back Pain
Workplace
Leg
Joints
Body Weight
Pressure

Keywords

  • Adult
  • Biomechanical Phenomena
  • Electromyography
  • Humans
  • Lumbar Vertebrae
  • Male
  • Muscle, Skeletal
  • Range of Motion, Articular
  • Reference Values
  • Weight Lifting
  • Comparative Study
  • Journal Article
  • Research Support, Non-U.S. Gov't

Cite this

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title = "Dynamic forces acting on the lumbar spine during manual handling. Can they be estimated using electromyographic techniques alone?",
abstract = "STUDY DESIGN: Compressive loading of the lumbar spine was analyzed using electromyographic, movement analysis, and force-plate techniques.OBJECTIVES: To evaluate the inertial forces that cannot be detected by electromyographic techniques alone.SUMMARY OF BACKGROUND DATA: Links between back pain and manual labor have stimulated attempts to measure spine compressive loading. However, direct measurements of intradiscal pressure are too invasive, and force plates too cumbersome for use in the workplace. Electromyographic techniques are noninvasive and portable, but ignore certain inertial forces.METHODS: Eight men lifted boxes weighing 6.7 and 15.7 kg from the ground, while joint moments acting about L5-S1 were quantified 1) by using a linked-segment model to analyze data from Kistler force plates and a Vicon movement-analysis system, and 2) by measuring the electromyographic activity of the erector spinae muscles, correcting it for contraction speed and comparing it to moment generation during static contractions. The linked-segment model was used to calculate the {"}axial thrust,{"} defined as the component of the L5-S1 reaction force that acts along the axis of the spine and that is unrelated to trunk muscle activity or static body weight.RESULTS: Peak extensor moments predicted by the two techniques were similar and equivalent to spinal compressive forces of 2.9-4.8 kN. The axial thrust {"}hidden{"} from the electromyographic technique was negligible during slow lifts, and remained below 4{\%} of peak spinal compression even during fast heavy lifts. Peak axial thrust was proportional to the peak vertical ground reaction (R2 = 0.74).CONCLUSIONS: Electromyographic techniques can measure dynamic spinal loading, but additional force-plate data would improve accuracy slightly during lifts requiring a vigorous upward thrust from the legs.",
keywords = "Adult, Biomechanical Phenomena, Electromyography, Humans, Lumbar Vertebrae, Male, Muscle, Skeletal, Range of Motion, Articular, Reference Values, Weight Lifting, Comparative Study, Journal Article, Research Support, Non-U.S. Gov't",
author = "P. Dolan and I Kingma and {van Dieen}, J and {de Looze}, {M P} and Toussaint, {H M} and C.T.M. Baten and M.A. Adams",
year = "1999",
month = "4",
day = "1",
language = "English",
volume = "24",
pages = "698--703",
journal = "Spine",
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publisher = "Lippincott Williams & Wilkins",
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Dynamic forces acting on the lumbar spine during manual handling. Can they be estimated using electromyographic techniques alone? / Dolan, P.; Kingma, I; van Dieen, J; de Looze, M P; Toussaint, H M; Baten, C.T.M.; Adams, M.A.

In: Spine, Vol. 24, No. 7, 01.04.1999, p. 698-703.

Research output: Contribution to JournalArticleAcademicpeer-review

TY - JOUR

T1 - Dynamic forces acting on the lumbar spine during manual handling. Can they be estimated using electromyographic techniques alone?

AU - Dolan, P.

AU - Kingma, I

AU - van Dieen, J

AU - de Looze, M P

AU - Toussaint, H M

AU - Baten, C.T.M.

AU - Adams, M.A.

PY - 1999/4/1

Y1 - 1999/4/1

N2 - STUDY DESIGN: Compressive loading of the lumbar spine was analyzed using electromyographic, movement analysis, and force-plate techniques.OBJECTIVES: To evaluate the inertial forces that cannot be detected by electromyographic techniques alone.SUMMARY OF BACKGROUND DATA: Links between back pain and manual labor have stimulated attempts to measure spine compressive loading. However, direct measurements of intradiscal pressure are too invasive, and force plates too cumbersome for use in the workplace. Electromyographic techniques are noninvasive and portable, but ignore certain inertial forces.METHODS: Eight men lifted boxes weighing 6.7 and 15.7 kg from the ground, while joint moments acting about L5-S1 were quantified 1) by using a linked-segment model to analyze data from Kistler force plates and a Vicon movement-analysis system, and 2) by measuring the electromyographic activity of the erector spinae muscles, correcting it for contraction speed and comparing it to moment generation during static contractions. The linked-segment model was used to calculate the "axial thrust," defined as the component of the L5-S1 reaction force that acts along the axis of the spine and that is unrelated to trunk muscle activity or static body weight.RESULTS: Peak extensor moments predicted by the two techniques were similar and equivalent to spinal compressive forces of 2.9-4.8 kN. The axial thrust "hidden" from the electromyographic technique was negligible during slow lifts, and remained below 4% of peak spinal compression even during fast heavy lifts. Peak axial thrust was proportional to the peak vertical ground reaction (R2 = 0.74).CONCLUSIONS: Electromyographic techniques can measure dynamic spinal loading, but additional force-plate data would improve accuracy slightly during lifts requiring a vigorous upward thrust from the legs.

AB - STUDY DESIGN: Compressive loading of the lumbar spine was analyzed using electromyographic, movement analysis, and force-plate techniques.OBJECTIVES: To evaluate the inertial forces that cannot be detected by electromyographic techniques alone.SUMMARY OF BACKGROUND DATA: Links between back pain and manual labor have stimulated attempts to measure spine compressive loading. However, direct measurements of intradiscal pressure are too invasive, and force plates too cumbersome for use in the workplace. Electromyographic techniques are noninvasive and portable, but ignore certain inertial forces.METHODS: Eight men lifted boxes weighing 6.7 and 15.7 kg from the ground, while joint moments acting about L5-S1 were quantified 1) by using a linked-segment model to analyze data from Kistler force plates and a Vicon movement-analysis system, and 2) by measuring the electromyographic activity of the erector spinae muscles, correcting it for contraction speed and comparing it to moment generation during static contractions. The linked-segment model was used to calculate the "axial thrust," defined as the component of the L5-S1 reaction force that acts along the axis of the spine and that is unrelated to trunk muscle activity or static body weight.RESULTS: Peak extensor moments predicted by the two techniques were similar and equivalent to spinal compressive forces of 2.9-4.8 kN. The axial thrust "hidden" from the electromyographic technique was negligible during slow lifts, and remained below 4% of peak spinal compression even during fast heavy lifts. Peak axial thrust was proportional to the peak vertical ground reaction (R2 = 0.74).CONCLUSIONS: Electromyographic techniques can measure dynamic spinal loading, but additional force-plate data would improve accuracy slightly during lifts requiring a vigorous upward thrust from the legs.

KW - Adult

KW - Biomechanical Phenomena

KW - Electromyography

KW - Humans

KW - Lumbar Vertebrae

KW - Male

KW - Muscle, Skeletal

KW - Range of Motion, Articular

KW - Reference Values

KW - Weight Lifting

KW - Comparative Study

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

M3 - Article

VL - 24

SP - 698

EP - 703

JO - Spine

T2 - Spine

JF - Spine

SN - 0362-2436

IS - 7

ER -