Coupled objective function to study the role of abdominal muscle forces in lifting using the kinematics-driven model

To circumvent the existing shortcoming of optimisation algorithms in trunk biomechanical models, both agonist and antagonist trunk muscle stresses to different powers are introduced in a novel objective function to evaluate the role of abdominal muscles in trunk stability and spine compression. This coupled objective function is introduced in our kinematics-driven finite element model to estimate muscle forces and to identify the role of abdominal muscles in upright standing while lifting symmetrically a weight at different heights. Predictive equations for the compression and buckling forces are developed. Results are also compared with the conventional objective function that neglects abdominal muscle forces. An overall optimal solution involving smaller spinal compression but higher trunk stability is automatically attained when choosing muscle stress powers at and around 3. Results highlight the internal oblique muscle as the most efficient abdominal muscle during the tasks investigated. The estimated relative forces in abdominal muscles are found to be in good agreement with the respective ratios of recorded electromyography activities.

[1]  G A Mirka,et al.  Transverse-Contour Modeling of Trunk Muscle–Distributed Forces and Spinal Loads During Lifting and Twisting , 2000, Spine.

[2]  I. Stokes,et al.  The Effects of Abdominal Muscle Coactivation on Lumbar Spine Stability , 1998, Spine.

[3]  A. Bergmark.  Stability of the lumbar spine. A study in mechanical engineering. , 1989, Acta orthopaedica Scandinavica. Supplementum.

[4]  N Arjmand,et al.  A novel approach to evaluate abdominal coactivities for optimal spinal stability and compression force in lifting , 2009, Computer methods in biomechanics and biomedical engineering.

[5]  M M Panjabi,et al.  Euler stability of the human ligamentous lumbar spine. Part I: Theory. , 1992, Clinical biomechanics.

[6]  Bente Schibye,et al.  Intra-Abdominal Pressure and Activation of Abdominal Muscles in Highly Trained Participants During Sudden Heavy Trunk Loadings , 2004, Spine.

[7]  Margaret J. Robertson,et al.  Design and Analysis of Experiments , 2006, Handbook of statistics.

[8]  M J Pearcy,et al.  A three-dimensional mathematical model of the thoracolumbar fascia and an estimate of its biomechanical effect. , 2010, Journal of biomechanics.

[9]  R. Hughes,et al.  Evaluating the effect of co-contraction in optimization models. , 1995, Journal of biomechanics.

[10]  M. Parnianpour,et al.  Trunk biomechanics during maximum isometric axial torque exertions in upright standing. , 2008, Clinical biomechanics.

[11]  A Shirazi-Adl,et al.  Analysis of large compression loads on lumbar spine in flexion and in torsion using a novel wrapping element. , 2006, Journal of biomechanics.

[12]  N Arjmand,et al.  Wrapping of trunk thoracic extensor muscles influences muscle forces and spinal loads in lifting tasks. , 2006, Clinical biomechanics.

[13]  Aboulfazl Shirazi-Adl,et al.  Biomechanics of Changes in Lumbar Posture in Static Lifting , 2005, Spine.

[14]  N Arjmand,et al.  Sensitivity of kinematics-based model predictions to optimization criteria in static lifting tasks. , 2006, Medical engineering & physics.

[15]  R. Raikova.  About weight factors in the non-linear objective functions used for solving indeterminate problems in biomechanics. , 1999, Journal of biomechanics.

[16]  Babak Bazrgari,et al.  Analysis of squat and stoop dynamic liftings: muscle forces and internal spinal loads , 2007, European Spine Journal.

[17]  M. Parnianpour,et al.  Trunk biomechanical models based on equilibrium at a single-level violate equilibrium at other levels , 2007, European Spine Journal.

[18]  R. Crowninshield,et al.  A physiologically based criterion of muscle force prediction in locomotion. , 1981, Journal of biomechanics.

[19]  M J Pearcy,et al.  A Universal Model of the Lumbar Back Muscles in the Upright Position , 1992, Spine.

[20]  N. Arjmand,et al.  Role of intra-abdominal pressure in the unloading and stabilization of the human spine during static lifting tasks , 2006, European Spine Journal.

[21]  A. G. Cresswell.  Responses of intra-abdominal pressure and abdominal muscle activity during dynamic trunk loading in man , 2004, European Journal of Applied Physiology and Occupational Physiology.

[22]  A G Patwardhan,et al.  A frontal plane model of the lumbar spine subjected to a follower load: implications for the role of muscles. , 2001, Journal of biomechanical engineering.

[23]  Karl F. Orishimo,et al.  Response of trunk muscle coactivation to changes in spinal stability. , 2001, Journal of biomechanics.

[24]  Nikolai Bogduk,et al.  The morphology and biomechanics of latissimus dorsi. , 1998, Clinical biomechanics.

[25]  A. Shirazi-Adl,et al.  Muscle Activity, Internal Loads, and Stability of the Human Spine in Standing Postures: Combined Model and In Vivo Studies , 2004, Spine.

[26]  B. Prilutsky,et al.  Sensitivity of predicted muscle forces to parameters of the optimization-based human leg model revealed by analytical and numerical analyses. , 2001, Journal of biomechanics.

[27]  M. Parnianpour,et al.  Relative efficiency of abdominal muscles in spine stability , 2008, Computer methods in biomechanics and biomedical engineering.

[28]  S Gracovetsky.  Potential of lumbodorsal fascia forces to generate back extension moments during squat lifts. , 1989, Journal of biomedical engineering.

[29]  J H van Dieën,et al.  Abdominal muscles contribute in a minor way to peak spinal compression in lifting. , 1999, Journal of biomechanics.

[30]  A. G. Cresswell.  Responses of intra-abdominal pressure and abdominal muscle activity during dynamic trunk loading in man , 2004, European Journal of Applied Physiology and Occupational Physiology.

[31]  A Plamondon,et al.  Application of a Stereoradiographic Method for the Study of Intervertebral Motion , 1988, Spine.

[32]  P. Maurer,et al.  Trunk muscle recruitment patterns in specific chronic low back pain populations. , 2005, Clinical biomechanics.

[33]  A Plamondon,et al.  Comparison of trunk muscle forces and spinal loads estimated by two biomechanical models. , 2009, Clinical biomechanics.

[34]  D. Pearsall,et al.  Inertial properties of the human trunk of males determined from magnetic resonance imaging , 1994, Annals of Biomedical Engineering.

[35]  M. A. Townsend,et al.  Muscular synergism--I. On criteria for load sharing between synergistic muscles. , 1984, Journal of biomechanics.

[36]  N Arjmand,et al.  Model and in vivo studies on human trunk load partitioning and stability in isometric forward flexions. , 2006, Journal of biomechanics.

[37]  M. Panjabi,et al.  Euler stability of the human ligamentous lumbar spine. Part II: Experiment. , 1992, Clinical biomechanics.

[38]  I A Stokes,et al.  Quantitative anatomy of the lumbar musculature. , 1999, Journal of biomechanics.

[39]  P. Leva.  Adjustments to Zatsiorsky-Seluyanov's segment inertia parameters. , 1996 .

[40]  Mohamad Parnianpour,et al.  EMG activity normalization for trunk muscles in subjects with and without back pain. , 2002, Medicine and science in sports and exercise.

[41]  Karen A. F. Copeland.  Design and Analysis of Experiments, 5th Ed. , 2001 .

[42]  Babak Bazrgari,et al.  Influence of curved lines of action for trunk extensor muscles on load redistribution and stability of the spine during lifting , 2006 .