Validation of a personalized curved muscle model of the lumbar spine during complex dynamic exertions.

Previous curved muscle models have typically examined their robustness only under simple, single-plane static exertions. In addition, the empirical validation of curved muscle models through an entire lumbar spine has not been fully realized. The objective of this study was to empirically validate a personalized biologically-assisted curved muscle model during complex dynamic exertions. Twelve subjects performed a variety of complex lifting tasks as a function of load weight, load origin, and load height. Both a personalized curved muscle model as well as a straight-line muscle model were used to evaluate the model's fidelity and prediction of three-dimensional spine tissue loads under different lifting conditions. The curved muscle model showed better model performance and different spinal loading patterns through an entire lumbar spine compared to the straight-line muscle model. The curved muscle model generally showed good fidelity regardless of lifting condition. The majority of the 600 lifting tasks resulted in a coefficient of determination (R2) greater than 0.8 with an average of 0.83, and the average absolute error less than 15% between measured and predicted dynamic spinal moments. As expected, increased load and asymmetry were generally found to significantly increase spinal loads, demonstrating the ability of the model to differentiate between experimental conditions. A curved muscle model would be useful to estimate precise spine tissue loads under realistic circumstances. This precise assessment tool could aid in understanding biomechanical causal pathways for low back pain.

[1]  Bernd Markert,et al.  The muscle line of action in current models of the human cervical spine: a comparison with in vivo MRI data , 2012, Computer methods in biomechanics and biomedical engineering.

[2]  Kermit Davis,et al.  Load spatial pathway and spine loading: how does lift origin and destination influence low back response? , 2005, Ergonomics.

[3]  W S Marras,et al.  A stochastic model of trunk muscle coactivation during trunk bending. , 1993, Spine.

[4]  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.

[5]  A Garg,et al.  Revised NIOSH equation for the design and evaluation of manual lifting tasks. , 1993, Ergonomics.

[6]  D B Chaffin,et al.  Lumbar muscle force estimation using a subject-invariant 5-parameter EMG-based model. , 1998, Journal of biomechanics.

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

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

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

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

[11]  W S Marras,et al.  Significance of biomechanical and physiological variables during the determination of maximum acceptable weight of lift. , 1999, Ergonomics.

[12]  William S. Marras,et al.  A Simple Model of Changes in Lumbar Intervertebral Angles During Sagittal Torso Flexion , 2011 .

[13]  W. Marras,et al.  Differences in motor recruitment and resulting kinematics between low back pain patients and asymptomatic participants during lifting exertions. , 2004, Clinical biomechanics.

[14]  K P Granata,et al.  Relation between spinal load factors and the high-risk probability of occupational low-back disorder. , 1999, Ergonomics.

[15]  S. Delp,et al.  Influence of Muscle Morphometry and Moment Arms on the Moment‐Generating Capacity of Human Neck Muscles , 1998, Spine.

[16]  Bala Krishnamoorthy,et al.  Neck muscle paths and moment arms are significantly affected by wrapping surface parameters , 2012, Computer methods in biomechanics and biomedical engineering.

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

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

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

[20]  Sharon M Henry,et al.  Abdominal muscle activation increases lumbar spinal stability: analysis of contributions of different muscle groups. , 2011, Clinical biomechanics.

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

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

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

[24]  Jaejin Hwang,et al.  Curved muscles in biomechanical models of the spine: a systematic literature review , 2017, Ergonomics.

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

[26]  Kermit G. Davis,et al.  Assessment of the Relationship between Box Weight and Trunk Kinematics: Does a Reduction in Box Weight Necessarily Correspond to a Decrease in Spinal Loading? , 2000, Hum. Factors.

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

[28]  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.

[29]  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.

[30]  C Larivière,et al.  Comparative ability of EMG, optimization, and hybrid modelling approaches to predict trunk muscle forces and lumbar spine loading during dynamic sagittal plane lifting. , 2001, Clinical biomechanics.

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

[32]  W. M. Keyserling,et al.  Back disorders and nonneutral trunk postures of automobile assembly workers. , 1991, Scandinavian journal of work, environment & health.

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

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

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

[36]  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.

[37]  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.

[38]  William S Marras,et al.  Gender influences on spine loads during complex lifting. , 2003, The spine journal : official journal of the North American Spine Society.

[39]  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.

[40]  Alexander Aurand,et al.  A biologically-assisted curved muscle model of the lumbar spine: Model structure. , 2016, Clinical biomechanics.

[41]  A Shirazi-Adl,et al.  Seated whole body vibrations with high-magnitude accelerations--relative roles of inertia and muscle forces. , 2008, Journal of biomechanics.

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

[43]  Antonius Rohlmann,et al.  An enhanced and validated generic thoraco-lumbar spine model for prediction of muscle forces. , 2012, Medical engineering & physics.

[44]  D W van Lopik,et al.  Development of a multi-body computational model of human head and neck , 2007 .