A biologically-assisted curved muscle model of the lumbar spine: Model validation

Jaejin Hwang, Gregory G. Knapik, Jonathan S. Dufour, Thomas Best, Safdar N. Khan, Ehud Mendel, William S. Marras

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Background Biomechanical models have been developed to predict spinal loads in vivo to assess potential risk of injury in workplaces. Most models represent trunk muscles with straight-lines. Even though straight-line muscles behave reasonably well in simple exertions, they could be less reliable during complex dynamic exertions. A curved muscle representation was developed to overcome this issue. However, most curved muscle models have not been validated during dynamic exertions. Thus, the objective of this study was to investigate the fidelity of a curved muscle model during complex dynamic lifting tasks, and to investigate the changes in spine tissue loads. Methods Twelve subjects (7 males and 5 females) participated in this study. Subjects performed lifting tasks as a function of load weight, load origin, and load height to simulate complex exertions. Moment matching measures were recorded to evaluate how well the model predicted spinal moments compared to measured spinal moments from T12/L1 to L5/S1 levels. Findings The biologically-assisted curved muscle model demonstrated better model performance than the straight-line muscle model between various experimental conditions. In general, the curved muscle model predicted at least 80% of the variability in spinal moments, and less than 15% of average absolute error across levels. The model predicted that the compression and anterior–posterior shear load significantly increased as trunk flexion increased, whereas the lateral shear load significantly increased as trunk twisted more asymmetric during lifting tasks. Interpretation A curved muscle representation in a biologically-assisted model is an empirically reasonable approach to accurately predict spinal moments and spinal tissue loads of the lumbar spine.

Original languageEnglish (US)
Pages (from-to)153-159
Number of pages7
JournalClinical Biomechanics
Volume37
DOIs
StatePublished - Aug 1 2016
Externally publishedYes

Fingerprint

Spine
Muscles
Workplace
Weights and Measures
Wounds and Injuries

Keywords

  • Biomechanical model
  • Curved muscle
  • Spine
  • Validation
  • Wrapping muscle

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine

Cite this

A biologically-assisted curved muscle model of the lumbar spine : Model validation. / Hwang, Jaejin; Knapik, Gregory G.; Dufour, Jonathan S.; Best, Thomas; Khan, Safdar N.; Mendel, Ehud; Marras, William S.

In: Clinical Biomechanics, Vol. 37, 01.08.2016, p. 153-159.

Research output: Contribution to journalArticle

Hwang, Jaejin ; Knapik, Gregory G. ; Dufour, Jonathan S. ; Best, Thomas ; Khan, Safdar N. ; Mendel, Ehud ; Marras, William S. / A biologically-assisted curved muscle model of the lumbar spine : Model validation. In: Clinical Biomechanics. 2016 ; Vol. 37. pp. 153-159.
@article{7f136e10370a4955bb027c647581fd2c,
title = "A biologically-assisted curved muscle model of the lumbar spine: Model validation",
abstract = "Background Biomechanical models have been developed to predict spinal loads in vivo to assess potential risk of injury in workplaces. Most models represent trunk muscles with straight-lines. Even though straight-line muscles behave reasonably well in simple exertions, they could be less reliable during complex dynamic exertions. A curved muscle representation was developed to overcome this issue. However, most curved muscle models have not been validated during dynamic exertions. Thus, the objective of this study was to investigate the fidelity of a curved muscle model during complex dynamic lifting tasks, and to investigate the changes in spine tissue loads. Methods Twelve subjects (7 males and 5 females) participated in this study. Subjects performed lifting tasks as a function of load weight, load origin, and load height to simulate complex exertions. Moment matching measures were recorded to evaluate how well the model predicted spinal moments compared to measured spinal moments from T12/L1 to L5/S1 levels. Findings The biologically-assisted curved muscle model demonstrated better model performance than the straight-line muscle model between various experimental conditions. In general, the curved muscle model predicted at least 80{\%} of the variability in spinal moments, and less than 15{\%} of average absolute error across levels. The model predicted that the compression and anterior–posterior shear load significantly increased as trunk flexion increased, whereas the lateral shear load significantly increased as trunk twisted more asymmetric during lifting tasks. Interpretation A curved muscle representation in a biologically-assisted model is an empirically reasonable approach to accurately predict spinal moments and spinal tissue loads of the lumbar spine.",
keywords = "Biomechanical model, Curved muscle, Spine, Validation, Wrapping muscle",
author = "Jaejin Hwang and Knapik, {Gregory G.} and Dufour, {Jonathan S.} and Thomas Best and Khan, {Safdar N.} and Ehud Mendel and Marras, {William S.}",
year = "2016",
month = "8",
day = "1",
doi = "10.1016/j.clinbiomech.2016.07.009",
language = "English (US)",
volume = "37",
pages = "153--159",
journal = "Clinical Biomechanics",
issn = "0268-0033",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - A biologically-assisted curved muscle model of the lumbar spine

T2 - Model validation

AU - Hwang, Jaejin

AU - Knapik, Gregory G.

AU - Dufour, Jonathan S.

AU - Best, Thomas

AU - Khan, Safdar N.

AU - Mendel, Ehud

AU - Marras, William S.

PY - 2016/8/1

Y1 - 2016/8/1

N2 - Background Biomechanical models have been developed to predict spinal loads in vivo to assess potential risk of injury in workplaces. Most models represent trunk muscles with straight-lines. Even though straight-line muscles behave reasonably well in simple exertions, they could be less reliable during complex dynamic exertions. A curved muscle representation was developed to overcome this issue. However, most curved muscle models have not been validated during dynamic exertions. Thus, the objective of this study was to investigate the fidelity of a curved muscle model during complex dynamic lifting tasks, and to investigate the changes in spine tissue loads. Methods Twelve subjects (7 males and 5 females) participated in this study. Subjects performed lifting tasks as a function of load weight, load origin, and load height to simulate complex exertions. Moment matching measures were recorded to evaluate how well the model predicted spinal moments compared to measured spinal moments from T12/L1 to L5/S1 levels. Findings The biologically-assisted curved muscle model demonstrated better model performance than the straight-line muscle model between various experimental conditions. In general, the curved muscle model predicted at least 80% of the variability in spinal moments, and less than 15% of average absolute error across levels. The model predicted that the compression and anterior–posterior shear load significantly increased as trunk flexion increased, whereas the lateral shear load significantly increased as trunk twisted more asymmetric during lifting tasks. Interpretation A curved muscle representation in a biologically-assisted model is an empirically reasonable approach to accurately predict spinal moments and spinal tissue loads of the lumbar spine.

AB - Background Biomechanical models have been developed to predict spinal loads in vivo to assess potential risk of injury in workplaces. Most models represent trunk muscles with straight-lines. Even though straight-line muscles behave reasonably well in simple exertions, they could be less reliable during complex dynamic exertions. A curved muscle representation was developed to overcome this issue. However, most curved muscle models have not been validated during dynamic exertions. Thus, the objective of this study was to investigate the fidelity of a curved muscle model during complex dynamic lifting tasks, and to investigate the changes in spine tissue loads. Methods Twelve subjects (7 males and 5 females) participated in this study. Subjects performed lifting tasks as a function of load weight, load origin, and load height to simulate complex exertions. Moment matching measures were recorded to evaluate how well the model predicted spinal moments compared to measured spinal moments from T12/L1 to L5/S1 levels. Findings The biologically-assisted curved muscle model demonstrated better model performance than the straight-line muscle model between various experimental conditions. In general, the curved muscle model predicted at least 80% of the variability in spinal moments, and less than 15% of average absolute error across levels. The model predicted that the compression and anterior–posterior shear load significantly increased as trunk flexion increased, whereas the lateral shear load significantly increased as trunk twisted more asymmetric during lifting tasks. Interpretation A curved muscle representation in a biologically-assisted model is an empirically reasonable approach to accurately predict spinal moments and spinal tissue loads of the lumbar spine.

KW - Biomechanical model

KW - Curved muscle

KW - Spine

KW - Validation

KW - Wrapping muscle

UR - http://www.scopus.com/inward/record.url?scp=84979743134&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84979743134&partnerID=8YFLogxK

U2 - 10.1016/j.clinbiomech.2016.07.009

DO - 10.1016/j.clinbiomech.2016.07.009

M3 - Article

C2 - 27484459

AN - SCOPUS:84979743134

VL - 37

SP - 153

EP - 159

JO - Clinical Biomechanics

JF - Clinical Biomechanics

SN - 0268-0033

ER -