I A F Stokes

Summary

Affiliation: University of Vermont
Country: USA

Publications

  1. ncbi request reprint Intervertebral disc changes in an animal model representing altered mechanics in scoliosis
    I A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, USA
    Stud Health Technol Inform 140:273-7. 2008
  2. ncbi request reprint Measurement of a spinal motion segment stiffness matrix
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    J Biomech 35:517-21. 2002
  3. pmc Trunk muscular activation patterns and responses to transient force perturbation in persons with self-reported low back pain
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Eur Spine J 15:658-67. 2006
  4. ncbi request reprint Computer-assisted algorithms improve reliability of King classification and Cobb angle measurement of scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Spine (Phila Pa 1976) 31:665-70. 2006
  5. pmc Endochondral growth in growth plates of three species at two anatomical locations modulated by mechanical compression and tension
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont 05405 0084, USA
    J Orthop Res 24:1327-34. 2006
  6. pmc Alterations in the growth plate associated with growth modulation by sustained compression or distraction
    Ian A F Stokes
    University of Vermont, Burlington, VT 05405 0084, USA
    Bone 41:197-205. 2007
  7. pmc Analysis and simulation of progressive adolescent scoliosis by biomechanical growth modulation
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, 434 Stafford Hall, Burlington, VT 05405 0084, USA
    Eur Spine J 16:1621-8. 2007
  8. ncbi request reprint Stature and growth compensation for spinal curvature
    I A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Stud Health Technol Inform 140:48-51. 2008
  9. pmc Classification of scoliosis deformity three-dimensional spinal shape by cluster analysis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Spine (Phila Pa 1976) 34:584-90. 2009
  10. pmc Limitation of finite element analysis of poroelastic behavior of biological tissues undergoing rapid loading
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Ann Biomed Eng 38:1780-8. 2010

Detail Information

Publications36

  1. ncbi request reprint Intervertebral disc changes in an animal model representing altered mechanics in scoliosis
    I A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, USA
    Stud Health Technol Inform 140:273-7. 2008
    ..Further studies are in progress to characterize gene expression, matrix protein synthesis and composition in these discs...
  2. ncbi request reprint Measurement of a spinal motion segment stiffness matrix
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    J Biomech 35:517-21. 2002
    ..Results from a pig lumbar spinal motion segment in an isotonic bath, with and without a 500 N axial preload, showed a large stiffening effect with axial preload...
  3. pmc Trunk muscular activation patterns and responses to transient force perturbation in persons with self-reported low back pain
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Eur Spine J 15:658-67. 2006
    ..g., muscle atrophy) or reduced motivation (e.g., pain avoidance)...
  4. ncbi request reprint Computer-assisted algorithms improve reliability of King classification and Cobb angle measurement of scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Spine (Phila Pa 1976) 31:665-70. 2006
    ..Interobserver and intraobserver reliability study of improved method to evaluate radiographs of patients with scoliosis...
  5. pmc Endochondral growth in growth plates of three species at two anatomical locations modulated by mechanical compression and tension
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont 05405 0084, USA
    J Orthop Res 24:1327-34. 2006
    ..These data may be applicable to planning the management of progressive deformities in patients having residual growth...
  6. pmc Alterations in the growth plate associated with growth modulation by sustained compression or distraction
    Ian A F Stokes
    University of Vermont, Burlington, VT 05405 0084, USA
    Bone 41:197-205. 2007
    ..38 and 0.56 respectively). According to multiple linear regression coefficients for these two variables (0.72 and 1.39 respectively), chondrocytic enlargement made a greater contribution to altered growth rates...
  7. pmc Analysis and simulation of progressive adolescent scoliosis by biomechanical growth modulation
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, 434 Stafford Hall, Burlington, VT 05405 0084, USA
    Eur Spine J 16:1621-8. 2007
    ....
  8. ncbi request reprint Stature and growth compensation for spinal curvature
    I A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Stud Health Technol Inform 140:48-51. 2008
    ..Spinal curvatures alter measured stature and may influence the evaluation of skeletal maturity and growth based on stature measurements...
  9. pmc Classification of scoliosis deformity three-dimensional spinal shape by cluster analysis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Spine (Phila Pa 1976) 34:584-90. 2009
    ..Cluster analysis of existing database of spinal shape of patients attending a scoliosis clinic...
  10. pmc Limitation of finite element analysis of poroelastic behavior of biological tissues undergoing rapid loading
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Ann Biomed Eng 38:1780-8. 2010
    ..Pressure instabilities may impose limitations on the use of the finite element method for simulating fluid transport behaviors of biological soft tissues at moderately rapid physiological loading rates...
  11. doi request reprint Intra-abdominal pressure and abdominal wall muscular function: Spinal unloading mechanism
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Clin Biomech (Bristol, Avon) 25:859-66. 2010
    ..Biomechanical analyses are needed to understand the function of intra-abdominal pressurization because of the anatomical and physiological complexity, but prior analyses have been over-simplified...
  12. pmc Refinement of elastic, poroelastic, and osmotic tissue properties of intervertebral disks to analyze behavior in compression
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Stafford Hall, Burlington, VT 05405 0084, USA
    Ann Biomed Eng 39:122-31. 2011
    ..55 and 2.6. Force relaxation and time constants from the analytical simulations were most sensitive to values of fixed charge density and endplate porosity...
  13. doi request reprint Abdominal muscle activation increases lumbar spinal stability: analysis of contributions of different muscle groups
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, USA
    Clin Biomech (Bristol, Avon) 26:797-803. 2011
    ..This biomechanical analytical study addressed whether lumbar spinal stability is increased by such selective activation...
  14. ncbi request reprint Modulation of vertebral and tibial growth by compression loading: diurnal versus full-time loading
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation, McClure Musculoskeletal Research Center, Robert T Stafford Hall, University of Vermont, Burlington, VT 05405 0084, USA
    J Orthop Res 23:188-95. 2005
    ..This study was designed to determine whether the amount of endochondral growth response to mechanical compression and the underlying growth mechanism differed with night-time or day-time loading, relative to full-time loading...
  15. ncbi request reprint Relationships of EMG to effort in the trunk under isometric conditions: force-increasing and decreasing effects and temporal delays
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Stafford Hall 434, Burlington, VT 05405 0084, USA
    Clin Biomech (Bristol, Avon) 20:9-15. 2005
    ....
  16. ncbi request reprint Identifying sources of variability in scoliosis classification using a rule-based automated algorithm
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont 05405, USA
    Spine (Phila Pa 1976) 27:2801-5. 2002
    ..Use of a rule-based automated algorithm to determine sources of variability in radiographic classification...
  17. ncbi request reprint Surface EMG electrodes do not accurately record from lumbar multifidus muscles
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Clin Biomech (Bristol, Avon) 18:9-13. 2003
    ..This study investigated whether electromyographic signals recorded from the skin surface overlying the multifidus muscles could be used to quantify their activity...
  18. ncbi request reprint Spinal stiffness increases with axial load: another stabilizing consequence of muscle action
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    J Electromyogr Kinesiol 13:397-402. 2003
    ....
  19. ncbi request reprint Muscle activation strategies and symmetry of spinal loading in the lumbar spine with scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Spine (Phila Pa 1976) 29:2103-7. 2004
    ..Biomechanical analysis of muscle and spinal forces in a lumbar spine with scoliosis...
  20. pmc Intervertebral disc changes with angulation, compression and reduced mobility simulating altered mechanical environment in scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Eur Spine J 20:1735-44. 2011
    ..The purpose of this study was to document morphological and biomechanical changes in four different models of altered mechanical environment in intervertebral discs of growing rats and in a sham and control groups...
  21. ncbi request reprint Motion segment stiffness measured without physiological levels of axial compressive preload underestimates the in vivo values in all six degrees of freedom
    Mark G Gardner-Morse
    Department of Orthopaedics and Rehabilitation, University of Vermont, Stafford Hall, Burlington, Vermont 05405 0084, USA
    Stud Health Technol Inform 91:167-72. 2002
    ..The stiffness, hysteresis area and linearity of six diagonal and two off-diagonal load-displacement relationships were examined for differences between preload conditions...
  22. pmc Frequency-dependent behavior of the intervertebral disc in response to each of six degree of freedom dynamic loading: solid phase and fluid phase contributions
    John J Costi
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington
    Spine (Phila Pa 1976) 33:1731-8. 2008
    ..Nondestructive displacement-controlled dynamic testing of cadaver material, with repeated measures design and randomized sequence of tests...
  23. ncbi request reprint Physiological axial compressive preloads increase motion segment stiffness, linearity and hysteresis in all six degrees of freedom for small displacements about the neutral posture
    Mack G Gardner-Morse
    Department of Orthopaedics and Rehabilitation, University of Vermont, Stafford Hall, Burlington 05405 0084, USA
    J Orthop Res 21:547-52. 2003
    ..82, 0.97 and 0.98 at 0, 200 and 400 N axial compression respectively). Motion segment and disc load-displacement behaviors were stiffer, more linear and had greater hysteresis with axial compressive preloads...
  24. ncbi request reprint Mechanical modulation of vertebral and tibial growth: diurnal versus full-time loading
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation University of Vermont, Burlington, VT 05405 0084, USA
    Stud Health Technol Inform 91:97-100. 2002
    ....
  25. ncbi request reprint Growth plate chondrocyte enlargement modulated by mechanical loading
    Ian A Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Stud Health Technol Inform 88:378-81. 2002
    ..Thus mechanical loading of tail vertebrae modulated their growth rate, that in turn correlated with changes in the amount of hypertrophic chondrocyte height increase. The effects for compression were greater than for distraction...
  26. ncbi request reprint Enlargement of growth plate chondrocytes modulated by sustained mechanical loading
    Ian A Stokes
    University of Vermont, Burlington, Vermont 05405, USA
    J Bone Joint Surg Am 84:1842-8. 2002
    ....
  27. ncbi request reprint The role of remodeling and asymmetric growth in vertebral wedging
    David D Aronsson
    University of Vermont College of Medicine, Burlington, Vermont 05405, USA
    Stud Health Technol Inform 158:11-5. 2010
    ..We investigated whether vertebral wedging in scoliosis might involve both mechanisms...
  28. ncbi request reprint On the implications of interpreting the stability index: a spine example
    Mack G Gardner-Morse
    J Biomech 39:391-2; author reply 393-4. 2006
  29. ncbi request reprint Mechanical conditions that accelerate intervertebral disc degeneration: overload versus immobilization
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont 05405, USA
    Spine (Phila Pa 1976) 29:2724-32. 2004
    ..A review of the literature on macromechanical factors that accelerate disc degeneration with particular focus on distinguishing the roles of immobilization and overloading...
  30. ncbi request reprint Intervertebral disc adaptation to wedging deformation
    Ian A F Stokes
    University of Vermont, Orthopaedics and Rehabilitation, Burlington, Vermont, 05405 0084, USA
    Stud Health Technol Inform 123:182-7. 2006
    ..Although scoliosis includes wedge deformities of both vertebrae and discs, little is known about the causes of the discal changes, and whether they result from mechanical influences on growth and/or remodelling...
  31. ncbi request reprint Structural behavior of human lumbar spinal motion segments
    Mack G Gardner-Morse
    Department of Orthopaedics and Rehabilitation, University of Vermont, Stafford Hall, Burlington, VT 05405 0084, USA
    J Biomech 37:205-12. 2004
    ..These stiffness properties can be used in structural analyses of the lumbar spine...
  32. pmc Vertebral height growth predominates over intervertebral disc height growth in adolescents with scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Spine (Phila Pa 1976) 31:1600-4. 2006
    ..A cross-sectional study of spinal stereoradiographs of adolescents with scoliosis to measure growth...
  33. pmc Different effects of static versus cyclic compressive loading on rat intervertebral disc height and water loss in vitro
    Kazunori Masuoka
    University of Vermont, Burlington, VT 05405, USA
    Spine (Phila Pa 1976) 32:1974-9. 2007
    ..In vitro biomechanical study on rat caudal motion segments to evaluate association between compressive loading and water content under static and cyclic conditions...
  34. pmc Measurements of proteoglycan and water content distribution in human lumbar intervertebral discs
    James C Iatridis
    University of Vermont, Burlington, VT 05405, USA
    Spine (Phila Pa 1976) 32:1493-7. 2007
    ..Study of regional variations in composition in a sample of 9 mildly to moderately degenerated human intervertebral discs...
  35. ncbi request reprint Mechanical modulation of spinal growth and progression of adolescent scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405 0084, USA
    Stud Health Technol Inform 135:75-83. 2008
    ..Quantitative simulation of this mechanism demonstrates how therapeutic interventions to alter neuromuscular control of trunk muscles or otherwise modify spinal loading may alter the natural history of progression...
  36. ncbi request reprint Rule-based algorithm for automated King-type classification of idiopathic scoliosis
    Ian A F Stokes
    Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT 05405, USA
    Stud Health Technol Inform 88:149-52. 2002
    ..The algorithm overcame accuracy and reliability problems, except in rare cases when it was borderline whether or not a lumbar curve crossed the midline, when the apex level was ambiguous, or when a Cobb angle was close to 10 degrees...

Research Grants19

  1. Progressive scoliosis deformity in intervertebral disc
    Ian Stokes; Fiscal Year: 2007
    ..These approaches may include improvements in brace design, new possibilities for muscle rehabilitation, and surgical procedures aimed at early, minimally invasive modification of spinal growth. ..
  2. AN INTEGRATED MODEL OF INTERVERTEBRAL DISC FUNCTION
    Ian Stokes; Fiscal Year: 2006
    ..and the local conditions that can influence its metabolism, eventual composition and function in three-dimensions. ..
  3. MECHANICAL MODULATION OF GROWTH IN PHYSES
    Ian Stokes; Fiscal Year: 2003
    ..abstract_text> ..
  4. STABILITY OF MUSCULAR LOADING OF THE LUMBAR SPINE
    Ian Stokes; Fiscal Year: 2002
    ..In addition, the specific roles of individual muscles will be better elucidated, which will be helpful in guiding therapy for people with low back dysfunction. ..
  5. Progressive scoliosis deformity in intervertebral disc
    Ian Stokes; Fiscal Year: 2009
    ..These approaches may include improvements in brace design, new possibilities for muscle rehabilitation, and surgical procedures aimed at early, minimally invasive modification of spinal growth. ..