Samuel R Ward

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi request reprint The influence of patella alta on patellofemoral joint stress during normal and fast walking
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
    Clin Biomech (Bristol, Avon) 19:1040-7. 2004
  2. doi request reprint The architectural design of the gluteal muscle group: implications for movement and rehabilitation
    Samuel R Ward
    Department of Radiology, University of California San Diego, La Jolla, CA 92124, USA
    J Orthop Sports Phys Ther 40:95-102. 2010
  3. ncbi request reprint Influence of patella alta on knee extensor mechanics
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
    J Biomech 38:2415-22. 2005
  4. doi request reprint Plasticity of muscle architecture after supraspinatus tears
    Samuel R Ward
    Department of Radiology, University of California and Veterans Administration Medical Centers, San Diego, CA, USA
    J Orthop Sports Phys Ther 40:729-35. 2010
  5. pmc A novel muscle biopsy clamp yields accurate in vivo sarcomere length values
    Samuel R Ward
    Department of Orthopaedic Surgery, University of California and Veterans Administration Medical Center, San Diego, CA 92161, USA
    J Biomech 42:193-6. 2009
  6. ncbi request reprint Patella alta: association with patellofemoral alignment and changes in contact area during weight-bearing
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089, USA
    J Bone Joint Surg Am 89:1749-55. 2007
  7. ncbi request reprint Effect of bracing on patellofemoral joint stress while ascending and descending stairs
    Christopher M Powers
    Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089 9006, USA
    Clin J Sport Med 14:206-14. 2004
  8. doi request reprint Psoas muscle architectural design, in vivo sarcomere length range, and passive tensile properties support its role as a lumbar spine stabilizer
    Gilad J Regev
    Department of Orthopaedic Surgery, University of California Medical Center, San Diego, CA, USA
    Spine (Phila Pa 1976) 36:E1666-74. 2011
  9. ncbi request reprint The effect of bracing on patellofemoral joint stress during free and fast walking
    Christopher M Powers
    Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California 90089 9006, USA
    Am J Sports Med 32:224-31. 2004
  10. pmc Asynchronous muscle and tendon adaptation after surgical tensioning procedures
    Mitsuhiko Takahashi
    Department of Orthopaedic Surgery, University of California and Veterans Affairs Medical Center, San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
    J Bone Joint Surg Am 92:664-74. 2010

Collaborators

Detail Information

Publications54

  1. ncbi request reprint The influence of patella alta on patellofemoral joint stress during normal and fast walking
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
    Clin Biomech (Bristol, Avon) 19:1040-7. 2004
    ..To determine if persons with patella alta exhibit elevated patellofemoral joint stress compared to pain-free controls during normal and fast walking speeds...
  2. doi request reprint The architectural design of the gluteal muscle group: implications for movement and rehabilitation
    Samuel R Ward
    Department of Radiology, University of California San Diego, La Jolla, CA 92124, USA
    J Orthop Sports Phys Ther 40:95-102. 2010
    ..These data demonstrate the architectural and functional specialization of the hip muscles, and highlight the importance of muscle physiology and joint mechanics when evaluating and treating musculoskeletal disorders...
  3. ncbi request reprint Influence of patella alta on knee extensor mechanics
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
    J Biomech 38:2415-22. 2005
    ..Therefore, persons with patella alta may experience less patellofemoral joint reaction force to overcome the same knee flexion moment in the range of 0 degrees -60 degrees of knee flexion...
  4. doi request reprint Plasticity of muscle architecture after supraspinatus tears
    Samuel R Ward
    Department of Radiology, University of California and Veterans Administration Medical Centers, San Diego, CA, USA
    J Orthop Sports Phys Ther 40:729-35. 2010
    ..Controlled laboratory study...
  5. pmc A novel muscle biopsy clamp yields accurate in vivo sarcomere length values
    Samuel R Ward
    Department of Orthopaedic Surgery, University of California and Veterans Administration Medical Center, San Diego, CA 92161, USA
    J Biomech 42:193-6. 2009
    ....
  6. ncbi request reprint Patella alta: association with patellofemoral alignment and changes in contact area during weight-bearing
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089, USA
    J Bone Joint Surg Am 89:1749-55. 2007
    ..We compared patellofemoral joint alignment and contact area in subjects who had patella alta with subjects who had normal patellar position, to determine the effect of high vertical patellar positions on knee extensor mechanics...
  7. ncbi request reprint Effect of bracing on patellofemoral joint stress while ascending and descending stairs
    Christopher M Powers
    Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089 9006, USA
    Clin J Sport Med 14:206-14. 2004
    ..To test the hypothesis that individuals who respond favorably to bracing will exhibit decreased patellofemoral joint stress during stair ambulation...
  8. doi request reprint Psoas muscle architectural design, in vivo sarcomere length range, and passive tensile properties support its role as a lumbar spine stabilizer
    Gilad J Regev
    Department of Orthopaedic Surgery, University of California Medical Center, San Diego, CA, USA
    Spine (Phila Pa 1976) 36:E1666-74. 2011
    ..Controlled laboratory and cross-sectional study designs...
  9. ncbi request reprint The effect of bracing on patellofemoral joint stress during free and fast walking
    Christopher M Powers
    Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California 90089 9006, USA
    Am J Sports Med 32:224-31. 2004
    ..Although several studies have demonstrated decreases in patellofemoral pain (PFP) with the application of bracing, the mechanism by which bracing reduces symptoms has not been elucidated...
  10. pmc Asynchronous muscle and tendon adaptation after surgical tensioning procedures
    Mitsuhiko Takahashi
    Department of Orthopaedic Surgery, University of California and Veterans Affairs Medical Center, San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
    J Bone Joint Surg Am 92:664-74. 2010
    ..This study was performed to evaluate muscle-tendon-unit adaptation to tendon transfer surgery in an animal model...
  11. pmc Passive mechanical properties and related proteins change with botulinum neurotoxin A injection of normal skeletal muscle
    Bryan E Thacker
    Department of Bioengineering, University of California and Veterans Administration Medical Centers San Diego, La Jolla, California, USA
    J Orthop Res 30:497-502. 2012
    ..Injection of botulinum neurotoxin A produces an effect on the passive mechanical properties of normal muscle that is opposite to the changes observed in spastic muscles...
  12. doi request reprint ISSLS prize winner: Adaptations to the multifidus muscle in response to experimentally induced intervertebral disc degeneration
    Stephen H M Brown
    Department of Orthopaedic Surgery, University of California San Diego, San Diego, CA 92093, USA
    Spine (Phila Pa 1976) 36:1728-36. 2011
    ..Basic science study of the rabbit multifidus muscle response to intervertebral disc degeneration...
  13. pmc Whole muscle length-tension relationships are accurately modeled as scaled sarcomeres in rabbit hindlimb muscles
    Taylor M Winters
    Department of Bioengineering, University of California and Veterans Administration Medical Centers 3350 La Jolla Village Drive, San Diego, CA 92161, USA
    J Biomech 44:109-15. 2011
    ....
  14. pmc Mechanical strength of the side-to-side versus Pulvertaft weave tendon repair
    Stephen H M Brown
    Departments of Orthopaedic Surgery and Radiology, University of California, San Diego, San Diego, CA, USA
    J Hand Surg Am 35:540-5. 2010
    ..This study was designed to test the strength and stiffness of the SS technique against a variation of the Pulvertaft (PT) repair technique...
  15. pmc Regional Myosin heavy chain distribution in selected paraspinal muscles
    Gilad J Regev
    Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA 92093, USA
    Spine (Phila Pa 1976) 35:1265-70. 2010
    ..Cross-sectional study with repeated measures design...
  16. pmc Theoretical predictions of the effects of force transmission by desmin on intersarcomere dynamics
    Gretchen A Meyer
    Department of Bioengineering, University of California, San Diego, California, USA
    Biophys J 98:258-66. 2010
    ....
  17. pmc Passive mechanical properties of rat abdominal wall muscles suggest an important role of the extracellular connective tissue matrix
    Stephen H M Brown
    Department of Orthopaedic Surgery, University of California San Diego, Research Service VA San Diego Healthcare System San Diego, California, USA
    J Orthop Res 30:1321-6. 2012
    ..Titin molecular mass was significantly less in TrA compared to each of the other three muscles (p < 0.0009), but this difference did not correspond to hypothesized differences in stiffness...
  18. ncbi request reprint The effect of bracing on patella alignment and patellofemoral joint contact area
    Christopher M Powers
    Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90036, USA
    Med Sci Sports Exerc 36:1226-32. 2004
    ..To examine the influence of two patellofemoral braces on pain response, patellar alignment, and patellofemoral joint contact area in persons with patellofemoral pain...
  19. pmc Correlation between isometric force and intramuscular pressure in rabbit tibialis anterior muscle with an intact anterior compartment
    Taylor M Winters
    Department of Bioengineering, University of California San Diego, San Diego, California, USA
    Muscle Nerve 40:79-85. 2009
    ..98 +/- 0.01 for the active descending limb. These data demonstrate that muscle force and IMP are fairly well correlated under isometric conditions and that this relationship is not improved by measuring IMP in an intact environment...
  20. ncbi request reprint Patellofemoral kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella: a preliminary study
    Christopher M Powers
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southem California, Los Angles, CA, USA
    J Orthop Sports Phys Ther 33:677-85. 2003
    ..Single-group, repeated-measures design...
  21. pmc Muscle excursion does not correlate with increased serial sarcomere number after muscle adaptation to stretched tendon transfer
    Mitsuhiko Takahashi
    Orthopaedic Surgery, University of California and Research Service, VA San Diego Healthcare System, San Diego, CA, USA
    J Orthop Res 30:1774-80. 2012
    ..These data have significant implications for examining muscle physiological properties under surgical interventions...
  22. ncbi request reprint Dorsal transfer of the brachioradialis to the flexor pollicis longus enables simultaneous powering of key pinch and forearm pronation
    Samuel R Ward
    Department of Radiology, University of California and Veterans Administration San Diego, San Diego, CA 92161, USA
    J Hand Surg Am 31:993-7. 2006
    ..To show biomechanically that the brachioradialis (BR) muscle can be transferred to restore key pinch and forearm pronation simultaneously...
  23. pmc Architectural analysis and intraoperative measurements demonstrate the unique design of the multifidus muscle for lumbar spine stability
    Samuel R Ward
    Department of Orthopaedic Surgery, V A Medical Center and University of California at San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
    J Bone Joint Surg Am 91:176-85. 2009
    ....
  24. pmc Hamstring contractures in children with spastic cerebral palsy result from a stiffer extracellular matrix and increased in vivo sarcomere length
    Lucas R Smith
    Departments of Bioengineering, University of California, San Diego, CA, USA
    J Physiol 589:2625-39. 2011
    ....
  25. ncbi request reprint Rotator cuff muscle architecture: implications for glenohumeral stability
    Samuel R Ward
    Department of Orthopaedics and Bioengineering, University of California and Veterans Administration Medical Centers, San Diego, 92161, USA
    Clin Orthop Relat Res 448:157-63. 2006
    ..During surgery relatively small changes to rotator cuff muscle length may result in relatively large changes in shoulder function...
  26. ncbi request reprint Assessment of patellofemoral relationships using kinematic MRI: comparison between qualitative and quantitative methods
    Samuel R Ward
    Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles 90089 4500, USA
    J Magn Reson Imaging 16:69-74. 2002
    ..qualitative criteria to interpret images of the patellofemoral joint (PFJ) obtained using kinematic magnetic resonance (MR) imaging...
  27. ncbi request reprint Intraoperative single-site sarcomere length measurement accurately reflects whole-muscle sarcomere length in the rabbit
    Mitsuhiko Takahashi
    Department of Orthopaedic Surgery, University of California and Veterans Affairs Medical Centers, San Diego, CA 92161, USA
    J Hand Surg Am 32:612-7. 2007
    ..To compare single-site intraoperative sarcomere length values with sarcomere lengths measured from systematic sampling of the entire transferred muscle...
  28. pmc Mechanical feasibility of immediate mobilization of the brachioradialis muscle after tendon transfer
    Jan Friden
    Department of Orthopaedic Surgery, University of California San Diego, San Diego, CA, USA
    J Hand Surg Am 35:1473-8. 2010
    ..The purpose of this study was to measure the BR-FPL tendon tension across a range of wrist and elbow joint angles to determine whether joint motion could cause repair rupture...
  29. pmc Human skeletal muscle biochemical diversity
    Timothy F Tirrell
    Department of Orthopaedic Surgery, University of California San Diego, La Jolla, CA 92093, USA
    J Exp Biol 215:2551-9. 2012
    ..These trends suggest that distal muscles should have higher passive tension than proximal ones, and that titin size variability may potentially act to 'tune' the protein's mechanotransduction capability...
  30. ncbi request reprint Relationship between muscle stress and intramuscular pressure during dynamic muscle contractions
    Samuel R Ward
    Department of Radiology, University of California and Veterans Administration Medical Centers, San Diego, California 92161, USA
    Muscle Nerve 36:313-9. 2007
    ..They also illustrate the need to control transducer movement if muscle stress is to be inferred from IMP measurements such as might be desired during clinical gait testing...
  31. ncbi request reprint Quantification of patellofemoral joint contact area using magnetic resonance imaging
    Jacklyn Heino Brechter
    Department of Physical Therapy, Chapman University, Orange, CA, USA
    Magn Reson Imaging 21:955-9. 2003
    ..Developing a non-invasive technique to evaluate contact area will assist researchers and/or clinicians in obtaining patient-specific contact area data to be used in biomechanical analyses and clinical decision making...
  32. ncbi request reprint High stiffness of human digital flexor tendons is suited for precise finger positional control
    Samuel R Ward
    Department of Radiology, Biomedical Sciences Graduate Group, University of California, San Diego, California 92093, USA
    J Neurophysiol 96:2815-8. 2006
    ..Thus the high stiffness of the digital flexor tendons suits them well for fine positional control and would render their muscle spindles quite sensitive to length perturbations at the fingertips...
  33. doi request reprint Scaling of muscle architecture and fiber types in the rat hindlimb
    Carolyn M Eng
    Department of Orthopaedic Surgery, University of California and Veterans Administration Medical Centers, San Diego, CA, USA
    J Exp Biol 211:2336-45. 2008
    ..This implies that functional demands placed on muscles across species should be examined on the single muscle level...
  34. ncbi request reprint Pronator teres is an appropriate donor muscle for restoration of wrist and thumb extension
    Geoffrey D Abrams
    Department of Orthopaedics, University of California, San Diego, CA 92093 9151, USA
    J Hand Surg Am 30:1068-73. 2005
    ..To compare the detailed architectural properties of the pronator teres (PT), extensor carpi radialis brevis (ECRB), and extensor pollicis longus (EPL) muscles to evaluate the suitability of PT-to-ECRB and PT-to-EPL surgical procedures...
  35. pmc Architectural and morphological assessment of rat abdominal wall muscles: comparison for use as a human model
    Stephen H M Brown
    Department of Orthopaedic Surgery, University of California San Diego and VA Medical Center, San Diego, CA 92093 0863, USA
    J Anat 217:196-202. 2010
    ....
  36. ncbi request reprint Density and hydration of fresh and fixed human skeletal muscle
    Samuel R Ward
    Departments of Orthopaedic Surgery and Bioengineering, Veterans Affairs Medical Center and University of California San Diego, 3350 La Jolla Village Drive, La Jolla, CA, USA
    J Biomech 38:2317-20. 2005
    ..112+/-0.006 g/cm(3) in 4% formaldehyde-fixed muscle and 1.055+/-0.006 g/cm(3) in 37% formaldehyde-fixed muscle. These results indicate that the use of inappropriate hydration times or density values can produce PCSA errors of 5-10%...
  37. ncbi request reprint Muscle adaptation by serial sarcomere addition 1 year after femoral lengthening
    Jennette L Boakes
    Department of Orthopaedic Surgery, Shriners Hospital for Children, Sacramento, CA, USA
    Clin Orthop Relat Res 456:250-3. 2007
    ..This direct measurement of fascicle length and sarcomere length confirms sarcomerogenesis in human skeletal muscle secondary to chronic length change, and shows the capacity of human muscle to adapt to length changes...
  38. pmc Skeletal muscle design to meet functional demands
    Richard L Lieber
    Department of Orthopaedic Surgery, University of California San Diego, San Diego, CA 92121, USA
    Philos Trans R Soc Lond B Biol Sci 366:1466-76. 2011
    ..Taken together, the case is made that muscles can be fine-tuned to perform specific tasks that require actuators with a wide range of properties...
  39. pmc Are current measurements of lower extremity muscle architecture accurate?
    Samuel R Ward
    Department of Radiology, University of California and Veterans Administration Medical Centers, San Diego, CA, USA
    Clin Orthop Relat Res 467:1074-82. 2009
    ..These high-resolution data will facilitate the development of more accurate musculoskeletal models and challenge existing theories of muscle design; we believe they will aid in surgical decision making...
  40. ncbi request reprint Sarcomere length measurement permits high resolution normalization of muscle fiber length in architectural studies
    Amanda Felder
    Department of Orthopaedic Surgery, University of California, San Diego, CA 92161, USA
    J Exp Biol 208:3275-9. 2005
    ..We thus conclude that the use of sarcomere length normalization in architectural studies permits resolution of fiber length variations of 15% and may even be effective at resolving 10% fiber length variations...
  41. doi request reprint Effect of load carriage on lumbar spine kinematics
    Ana E Rodriguez-Soto
    Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
    Spine (Phila Pa 1976) 38:E783-91. 2013
    ..Feasibility study on the acquisition of lumbar spine kinematic data from upright magnetic resonance images obtained under heavy load carrying conditions...
  42. pmc Cellular mechanisms of tissue fibrosis. 4. Structural and functional consequences of skeletal muscle fibrosis
    Richard L Lieber
    Department of Orthopaedic Surgery, University of California San Diego, San Diego, California 92093 0863, USA
    Am J Physiol Cell Physiol 305:C241-52. 2013
    ..Approaches used to study fibrosis in tissues, such as lung, kidney, and liver, need to be applied to studies of skeletal muscle to identify ways to prevent or even cure the devastating maladies of skeletal muscle. ..
  43. pmc Muscle geometry affects accuracy of forearm volume determination by magnetic resonance imaging (MRI)
    Carolyn M Eng
    Department of Orthopaedic Surgery, University of California, San Diego, CA, USA
    J Biomech 40:3261-6. 2007
    ....
  44. doi request reprint Quantitative analysis of neonatal skeletal muscle functional improvement in the mouse
    David S Gokhin
    Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
    J Exp Biol 211:837-43. 2008
    ..These data provide the first specific structural basis for increases in muscle tension development during growth. Therefore, models of muscle growth must be modified to include an intrinsic quality enhancement component...
  45. pmc Passive mechanical properties of the lumbar multifidus muscle support its role as a stabilizer
    Samuel R Ward
    Department of Orthopaedic Surgery, University of California and Veterans Administration Medical Centers, San Diego, CA 92161, USA
    J Biomech 42:1384-9. 2009
    ..These data will provide key input variables for biomechanical modeling of normal and pathologic lumbar spine function and direct future work in biomechanical testing in these important muscles...
  46. pmc Sample size considerations in human muscle architecture studies
    Lori J Tuttle
    Department of Orthopaedic Surgery, University of California San Diego, San Diego, California, USA
    Muscle Nerve 45:742-5. 2012
    ..This report is a meta-analysis of the human muscle architecture literature that analyzes the number of muscles, number of subjects, and muscle fiber length coefficient of variation (CV) by body region...
  47. doi request reprint Capsular ligaments of the hip: anatomic, histologic, and positional study in cadaveric specimens with MR arthrography
    Felipe V Wagner
    Department of Radiology, University of California San Diego, San Diego, CA, USA
    Radiology 263:189-98. 2012
    ..To demonstrate the anatomy of the capsular ligaments of the hip by using magnetic resonance (MR) arthrography...
  48. doi request reprint The use of neural networks and texture analysis for rapid objective selection of regions of interest in cytoskeletal images
    Amanda D Felder Derkacs
    Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 0863, USA
    Microsc Microanal 18:115-22. 2012
    ..We found that this method was over 300 times faster than manual classification and that it permitted objective and accurate classification of image regions...
  49. ncbi request reprint Functional recovery of muscles after minimally invasive total hip arthroplasty
    Samuel R Ward
    Department of Radiology, University of California San Diego, San Diego, California, USA
    Instr Course Lect 57:249-54. 2008
    ..This finding suggests that the amount of muscle, or the particular muscle cut, does not have a significant effect on the recovery of postoperative gait function...
  50. pmc Novel transcriptional profile in wrist muscles from cerebral palsy patients
    Lucas R Smith
    Department of Bioengineering, University of California San Diego, La Jolla, California, USA
    BMC Med Genomics 2:44. 2009
    ..Further research is required to understand the mechanism of muscle adaptation to this upper motor neuron lesion that could lead to the development of innovative therapies...
  51. ncbi request reprint Increased efficacy and decreased systemic-effects of botulinum toxin A injection after active or passive muscle manipulation
    Viviane B Minamoto
    Department of Physical Therapy, Piracicaba Methodist University, Piracicaba, Brazil
    Dev Med Child Neurol 49:907-14. 2007
    ..These data demonstrate that both neuromuscular activity (seen in the ISO group) and muscle movement (seen in the PS group) increased the efficacy of BTX-A and decreased the systemic side effects...
  52. ncbi request reprint Concurrent criterion-related validity and reliability of a clinical device used to assess lateral patellar displacement
    Susumu Ota
    Program in Physical and Occupational Therapy, Nagoya University Graduate School of Medicine, Aichi, Japan
    J Orthop Sports Phys Ther 36:645-52. 2006
    ..Repeated-measures, within-subject design. Objective: To assess the concurrent criterion-related validity and reliability of a clinical device to quantify lateral patellar displacement...
  53. ncbi request reprint Passive muscle-tendon amplitude may not reflect skeletal muscle functional excursion
    Jan Friden
    Department of Hand Surgery, Sahlgrenska University Hospital, Goteborg, Sweden
    J Hand Surg Am 31:1105-10. 2006
    ..To quantify the gain in muscle mobility with progressive release of surrounding connective-tissue structures and to compare this property with the known architecture of each muscle...
  54. ncbi request reprint Postoperative pain management following total knee arthroplasty: a randomized comparison of continuous epidural versus femoral nerve infusion
    William T Long
    The Arthritis Institute, Inglewood, CA 90301, USA
    J Knee Surg 19:137-43. 2006