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

BACKGROUND Biomechanical models have been developed to assess the spine tissue loads of individuals. However, most models have assumed trunk muscle lines of action as straight-lines, which might be less reliable during occupational tasks that require complex lumbar motions. The objective of this study was to describe the model structure and underlying logic of a biologically-assisted curved muscle model of the lumbar spine. METHODS The developed model structure including curved muscle geometry, separation of active and passive muscle forces, and personalization of muscle properties was described. An example of the model procedure including data collection, personalization, and data evaluation was also illustrated. FINDINGS Three-dimensional curved muscle geometry was developed based on a predictive model using magnetic resonance imaging and anthropometric measures to personalize the model for each individual. Calibration algorithms were able to reverse-engineer personalized muscle properties to calculate active and passive muscle forces of each individual. INTERPRETATION This biologically-assisted curved muscle model will significantly increase the accuracy of spinal tissue load predictions for the entire lumbar spine during complex dynamic occupational tasks. Personalized active and passive muscle force algorithms will help to more robustly investigate person-specific muscle forces and spinal tissue loads.

[1]  P A Costigan,et al.  Prediction of Trunk Muscle Areas and Moment Arms by Use of Anthropometric Measures , 1987, Spine.

[2]  M Gagnon,et al.  Orientation and Moment Arms of Some Trunk Muscles , 1991, Spine.

[3]  A. Vasavada,et al.  Moving muscle points provide accurate curved muscle paths in a model of the cervical spine. , 2012, Journal of biomechanics.

[4]  R. Close.  Dynamic properties of mammalian skeletal muscles. , 1972, Physiological reviews.

[5]  J H van Dieën,et al.  Effects of antagonistic co-contraction on differences between electromyography based and optimization based estimates of spinal forces , 2005, Ergonomics.

[6]  R W Norman,et al.  Effects of an anatomically detailed erector spinae model on L4/L5 disc compression and shear. , 1987, Journal of biomechanics.

[7]  Stuart M McGill,et al.  Linking latest knowledge of injury mechanisms and spine function to the prevention of low back disorders. , 2004, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[8]  W. Marras,et al.  An EMG-assisted model of loads on the lumbar spine during asymmetric trunk extensions. , 1993, Journal of biomechanics.

[9]  Miloslav Vilimek.  Musculotendon forces derived by different muscle models. , 2007, Acta of bioengineering and biomechanics.

[10]  K P Granata,et al.  MRI-derived moment-arms of the female and male spine loading muscles. , 2001, Clinical biomechanics.

[11]  W. G. Allread,et al.  The Role of Dynamic Three-Dimensional Trunk Motion in Occupationally-Related Low Back Disorders: The Effects of Workplace Factors, Trunk Position, and Trunk Motion Characteristics on Risk of Injury , 1993, Spine.

[12]  M Parnianpour,et al.  Predictive equations to estimate spinal loads in symmetric lifting tasks. , 2011, Journal of biomechanics.

[13]  K P Granata,et al.  Female and male trunk geometry: size and prediction of the spine loading trunk muscles derived from MRI. , 2001, Clinical biomechanics.

[14]  W. Marras,et al.  Spine loading during trunk lateral bending motions. , 1997, Journal of biomechanics.

[15]  D B Chaffin,et al.  A computerized biomechanical model-development of and use in studying gross body actions. , 1969, Journal of biomechanics.

[16]  J. Fridén,et al.  In vivo measurement of human wrist extensor muscle sarcomere length changes. , 1994, Journal of neurophysiology.

[17]  William S Marras,et al.  An EMG-assisted model calibration technique that does not require MVCs. , 2013, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[18]  W S Marras,et al.  Intra-abdominal pressure during trunk extension motions. , 1996, Clinical biomechanics.

[19]  Richard A. Lasher,et al.  Defining and evaluating wrapping surfaces for MRI-derived spinal muscle paths. , 2008, Journal of biomechanics.

[20]  W S Marras,et al.  Measurements of Loads on the Lumbar Spine Under Isometric and Isokinetic Conditions , 1984, Spine.

[21]  R. Close.  Dynamic properties of fast and slow skeletal muscles of the rat during development , 1964, The Journal of physiology.

[22]  John Rasmussen,et al.  A generic detailed rigid-body lumbar spine model. , 2007, Journal of biomechanics.

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

[24]  William S. Marras,et al.  Modification of an EMG-assisted biomechanical model for pushing and pulling , 2007 .

[25]  A Plamondon,et al.  A comparative study of two trunk biomechanical models under symmetric and asymmetric loadings. , 2010, Journal of biomechanics.

[26]  D B Chaffin,et al.  Development and evaluation of a scalable and deformable geometric model of the human torso. , 1996, Clinical biomechanics.

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

[28]  D. Thelen.  Adjustment of muscle mechanics model parameters to simulate dynamic contractions in older adults. , 2003, Journal of biomechanical engineering.

[29]  W S Marras,et al.  A Three-Dimensional Motion Model of Loads on the Lumbar Spine: I. Model Structure , 1991, Human factors.

[30]  Miguel Christophy,et al.  A Musculoskeletal model for the lumbar spine , 2011, Biomechanics and Modeling in Mechanobiology.

[31]  E Y Chao,et al.  Muscle force analysis of the lumbar spine. , 1977, The Orthopedic clinics of North America.

[32]  Matej Daniel,et al.  A comparative study of muscle force estimates using Huxley's and Hill's muscle model , 2014, Computer methods in biomechanics and biomedical engineering.

[33]  William S Marras,et al.  Loading along the lumbar spine as influence by speed, control, load magnitude, and handle height during pushing. , 2009, Clinical biomechanics.

[34]  W C Hutton,et al.  Has the lumbar spine a margin of safety in forward bending? , 1986, Clinical biomechanics.

[35]  W. Marras,et al.  A Three-Dimensional Motion Model of Loads on the Lumbar Spine: II. Model Validation , 1991, Human factors.

[36]  Marcus G Pandy,et al.  Effect of muscle wrapping on model estimates of neck muscle strength , 2006, Computer methods in biomechanics and biomedical engineering.

[37]  J. Cholewicki,et al.  Mechanical stability of the in vivo lumbar spine: implications for injury and chronic low back pain. , 1996, Clinical biomechanics.

[38]  W. Marras,et al.  The Influence of Trunk Muscle Coactivity on Dynamic Spinal Loads , 1995, Spine.

[39]  W. Marras,et al.  Spine loading at different lumbar levels during pushing and pulling , 2009, Ergonomics.

[40]  Alf Thorstensson,et al.  The mechanics of back-extensor torque production about the lumbar spine. , 2003, Journal of biomechanics.

[41]  André Plamondon,et al.  An improved multi-joint EMG-assisted optimization approach to estimate joint and muscle forces in a musculoskeletal model of the lumbar spine. , 2011, Journal of biomechanics.

[42]  B Schibye,et al.  Mechanical load on the low back and shoulders during pushing and pulling of two-wheeled waste containers compared with lifting and carrying of bags and bins. , 2001, Clinical biomechanics.

[43]  W S. Marras,et al.  The development of an EMG-assisted model to assess spine loading during whole-body free-dynamic lifting. , 1997, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[44]  W. Marras,et al.  Spine loading in patients with low back pain during asymmetric lifting exertions. , 2004, The spine journal : official journal of the North American Spine Society.

[45]  J A Faulkner,et al.  Length-tension relationship of mammalian diaphragm muscles. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[46]  N Arjmand,et al.  A novel stability and kinematics-driven trunk biomechanical model to estimate muscle and spinal forces. , 2014, Medical engineering & physics.

[47]  J Cholewicki,et al.  Intra-abdominal pressure mechanism for stabilizing the lumbar spine. , 1999, Journal of biomechanics.

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

[49]  G Pettet,et al.  Modelling the line of action for the oblique abdominal muscles using an elliptical torso model. , 2001, Journal of biomechanics.

[50]  Kevin P Granata,et al.  Stability of Dynamic Trunk Movement , 2006, Spine.

[51]  A. Schultz,et al.  Analysis of Loads on the Lumbar Spine , 1981, Spine.

[52]  O. Schmitt.  The heat of shortening and the dynamic constants of muscle , 2017 .

[53]  Aboulfazl Shirazi-Adl,et al.  Effect of intervertebral translational flexibilities on estimations of trunk muscle forces, kinematics, loads, and stability , 2015, Computer methods in biomechanics and biomedical engineering.

[54]  W S Marras,et al.  Carrying and spine loading , 2013, Ergonomics.

[55]  S. Walker,et al.  I segment lengths and thin filament periods in skeletal muscle fibers of the rhesus monkey and the human , 1974, The Anatomical record.

[56]  R. Norman,et al.  1986 Volvo Award in Biomechanics: Partitioning of the L4 - L5 Dynamic Moment into Disc, Ligamentous, and Muscular Components During Lifting , 1986, Spine.

[57]  William S. Marras,et al.  A Biomechanical Assessment of Axial Twisting Exertions , 1995 .

[58]  Safdar N. Khan,et al.  Prediction of magnetic resonance imaging-derived trunk muscle geometry with application to spine biomechanical modeling. , 2016, Clinical biomechanics.

[59]  S. Gallagher,et al.  Tolerance of the lumbar spine to shear: a review and recommended exposure limits. , 2012, Clinical biomechanics.

[60]  W. Marras,et al.  An EMG-assisted model of trunk loading during free-dynamic lifting. , 1995, Journal of biomechanics.

[61]  A B Schultz,et al.  A model for semi-quantitative studies of muscle actions. , 1979, Journal of biomechanics.

[62]  Sharon M Henry,et al.  Intra-abdominal pressure and abdominal wall muscular function: Spinal unloading mechanism. , 2010, Clinical biomechanics.

[63]  R. L. Linscheid,et al.  Muscles across the elbow joint: a biomechanical analysis. , 1981, Journal of biomechanics.

[64]  W. Marras,et al.  Spine Loading Characteristics of Patients With Low Back Pain Compared With Asymptomatic Individuals , 2001, Spine.

[65]  D T Davy,et al.  An investigation of muscle lines of action about the hip: a centroid line approach vs the straight line approach. , 1975, Journal of biomechanics.

[66]  Safdar N. Khan,et al.  A biologically-assisted curved muscle model of the lumbar spine: Model validation. , 2016, Clinical biomechanics.