The Working Back: A Systems View
Low back pain affects 80% of the population at some point during their lifetime; it is responsiblefor over 40% of the compensation costs for work-related injuries. This book provides an understanding of the mechanisms influencing low back pain in the workplace and indicates how low back pain might be prevented, saving employers extraordinary amounts in medical costs and protecting workers from the most common on-the-job injury. With a unique, multidisciplinary perspective that shows how various influences or risk factors can be considered collectively, The Working Back: A Systems View:
Explains basic concepts in anatomy and physiology that are essential to understanding and preventing low back pain
Provides a systems perspective on the occupational causes of back pain, not only addressing factors such as spine loading, but also considering the potential impact of psychosocial and organizational interactions, genetics, and physiology
Discusses implementing preventive engineering and administrative controls and integrating risk interventions into the workplace
Offers an expert analysis of current medical research on low back pain in one comprehensive, accessible reference
This book gives readers the knowledge to assess a work environment and prescribe effective interventions. It is a hands-on reference for ergonomists, manufacturing engineers, process engineers, industrial engineers and managers, safety engineers, nurses, therapists, chiropractors, physicians, and workers with back pain. It is also an excellent resource for graduate or undergraduate students of kinesiology, physiology, ergonomics, physical therapy, nursing, industrial design, engineering, and general medicine.
Audience for the Book.
Apolitical Causality Assessment.
A Systems View of Low Back Pain Causality.
The Reality of Work.
How Might the Different Aspects of Work Be Associated with Back Pain.
Organization of the Book.
Chapter 2: Back Pain Magnitude and Potential Risk Factors.
What is back pain?
How common is back pain?
Back Pain at Work.
Epidemiology of Work Risk Factors.
Epidemiology of Physical Risk Factors.
Epidemiology of Individual (Personal) Risk Factors.
Social Class and Psychological Factors.
Epidemiology of Work-Related Psychosocial/Organizational Factors.
Potential Interaction of Physical and Psychosocial Factors.
Chapter 3: Function, Structure, and Support of the Back.
Bony Structures of the Spine.
The Disc (and the spinal joint).
Functional Spinal Unit.
End Plates and Nutrition.
Chapter 4: The Process of Pain.
What is Pain?
Origins of Pain.
The Pain Process.
The Inflammatory Process (Cytokines).
Peripheral Nervous System Sensitization.
Neuropathic Pain: The Cytokine Cascade and Nerve Sensitization.
Pain Mechanisms of the Central Nervous System.
Role of the Environment in Central Sensitization.
Implications for Low Back Pain.
Nerves at Risk of Sensitization.
Tissues at Risk of Sensitization.
Disc and Nerve Roots.
Muscular based Pain.
Lumbar Nerve Roots.
Relationship between Tissue Loading and Pain.
Chapter 5: Potential Pathways to Back Pain.
Views of Back Pain Causality.
A Unifying Model of Low Back Pain Pathways.
The Support Structure Disruption Pathways.
Support Structure Tolerance.
Disc Tolerance Summary.
The Muscle Function Disruption Pathway.
The Role of Individual Differences in the Pain Pathways.
Chapter 6: The Assessment of Biomechanical Forces Acting on the Low Back.
Biomechanical Concepts Applicable to the Back.
Load - Toleranc.
Moments and Levers.
External vs. Internal Loading.
How can we Modify Internal Spine Loads?
Biomechanical Arrangement of the Musculoskeletal Lever System.
The Impact of Velocity on Muscle Force.
Incorporating Spine Load Reductions into the Work System.
Loading of the Lumbar Spine.
Spine Load Assessments.
Models of Spine Load.
Biologically-Driven Modeling of Spine Loading.
Stability-Driven Spine Loading Models.
Predictions of Muscle (Motor) Control within Torso.
What Drives Motor Control- - The Mental Model.
Chapter 7: The Influence of Physical Work Factors on Muscle Activities and Spine Loads.
Industrial Quantitative Surveillance of Physical Exposure.
Strength Capacity Assessments of Work Load.
Static Analyses of Work Load.
Dynamic Analyses of Work Load.
Spine Loading and Task Performance.
Spine Loading and Primary Physical Workplace Factors.
Role of Trunk Muscle Cocontraction in Spine Loading.
Non-Sagittal Plane Loading.
One-Handed vs. Two-Handed Lifting.
Lifting vs. Lowering.
Duration of Exposure to Lifting Tasks.
Worker Experience, Task Frequency, and Moment Exposure.
Spine Loading associated with Modification of Physical Workplace Factors.
Lifting While Supporting the Body.
Pushing and Pulling.
Seated and Constrained Work Postures.
Physical Work Factor Summary.
Relationship between Spine Loading and Observed Risk of Low Back Pain.
Chapter 8: Psychosocial and Organizational Factor Influence on Spine Loading.
Psychosocial and Organizational Interactions.
Biomechanical Responses to Psychosocial Environment.
Biomechanical Responses to Mental Stress at Work.
Chapter 9: Individual Factors Role in Spine Loading.
Chapter 10: Physical, Individual, and Psychosocial/Organizational Risk Factor Interactions.
When Risk Factors Collide.
The Magnitude of Influence of the Three Risk Factor Categories.
Can Risk Factor Interactions be Predicted?
Chapter 11: Engineering Controls to Mediate Back Pain at Work: Tools for the Assessment of Physical Factor Impact on Spine Loads and Intervention.
Static Strength Prediction Programs.
Psychophysical Tolerance Limits.
Job Demand Index.
NIOSH Lifting Guide and Revised Equation.
The 1981 Lifting Guide.
The 1993 Revised Equation.
Video-based biomechanical models.
Lumbar Motion Monitor Risk Assessment.
Lifting Threshold Limit Values (TLVs).
Workplace Assessment Comparisons.
Chapter 12: Administrative Controls for the Workplace: Psychosocial and Organizational Interventions.
Implementing Psychosocial and Organizational Change.
Elements of the Process.
Traditional Administrative Controls.
Chapter 13: Integrating Risk Interventions into the Workplace.
Examples of Intervention Effectiveness.
Patient Handling Interventions.
Types of Physical Interventions.
Implementing both Physical and Psychosocial Interventions.
Distribution Center Interventions.
Chapter 14: Understanding Recurrent Low Back Pain and Implications for Return to Work.
The Natural History of Low Back Pain Recovery.
How can one Quantify the Extent of Low Back Pain?
Spine Loading of those Experiencing Low Back Pain.
Can Kinematic Impairment Assessments Predict Changes in Spine Loading?
Lifting Exposure Limits for Workers with LBP.
Recurrence of LBP and Work.
A Return-to Work Strategy.
Chapter 15: Conclusions.
William S. Marras PhD, is a Professor in the College of Engineering and the College of Medicine at The Ohio State University, a certified professional ergonomist, and a fellow of the American Institute of Medical and Biological Engineers, the Human Factors and Ergonomics Society, the International Ergonomics Society, and the Ergonomics Society. He holds two patents for devices for monitoring motion of the spine. He is an ergonomic consultant for the U.S. Department of Labor, Ford Motor Company, RCA, Honda, and other corporations and associations. He has had over 180 articles published in various medical and ergonomic journals and has coauthored several books on occupational ergonomics. He is currently the chair of the Human Factors Committee within the National Academy of Sciences.