Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Pain, Chronic


Related Terms

  • Chronic Pain Syndrome
  • Unresolved Pain

Differential Diagnosis

Specialists

  • Anesthesiologist
  • Clinical Psychologist
  • Dentist
  • Neurologist
  • Pain Medicine Physician/Pain Specialist
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Psychiatrist

Comorbid Conditions

Factors Influencing Duration

Although persons with chronic pain syndrome may have no objective medical impairment, their self-perception of incapacity depends on many variables, including character traits, personality, ethnic and cultural background, the presence of support systems, motivation and prior job satisfaction.

Medical Codes

ICD-9-CM:
338.21 - Chronic Pain Due to Trauma
338.22 - Chronic Post-thoracotomy Pain
338.28 - Chronic Postoperative Pain, Other
338.29 - Chronic Pain, Other
338.3 - Neoplasm Related Pain (Acute) (Chronic)
338.4 - Chronic Pain Syndrome; Chronic Pain Associated with Significant Psychosocial Dysfunction

Overview

Chronic pain generally refers to persistent, non-acute, sometimes disabling pain in the extremities or other areas of the body. The pain can be associated with a known cause such as a major or minor injury, or it can be a symptom of a painful chronic condition such as fibromyalgia. It can just as often be of unknown origin. Considerable controversy continues to surround the cause (etiology), definition, diagnosis, and treatment of chronic pain.

The term "chronic pain" is not used consistently. The term can refer to pain that has been present for an arbitrarily defined period, for example, longer than 6 months. Alternatively, the term "chronic pain" is often used as a synonym for the term "chronic pain syndrome," a descriptive term used to indicate persistent pain, subjective symptoms in excess of objective findings, associated dysfunctional pain behaviors, and self limitation in activities of daily living. Chronic pain syndrome is the presentation of combined physical and psychological changes due to chronic pain. It is not to be confused with “Complex regional pain syndrome” (CRPS), also called reflex sympathy dystrophy, which also involves chronic pain but is defined and diagnosed using an established set of clinical criteria.

Chronic pain syndrome is not the same as acute pain or recurrent acute pain. Acute pain is due to actual or pending tissue damage. Its duration is short and its psychosocial consequences are minimal. A person's perception of acute pain and behavior following the onset of acute pain are commensurate with the inciting event. Acute pain resolves as healing occurs. Acute pain is common, occurring for example with fractured bones, skin lacerations, sprains and other similar events. Recurrent, acute pain refers to episodic pain associated with chronic conditions such as trigeminal neuralgia or cluster migraine headaches.

Although chronic pain differs from acute pain, the current understanding of neurophysiologic mechanisms involved in the development and persistence of pain recognizes that transmission of pain (nociceptive signals) from peripheral sites results in changes at all levels of the central nervous system (CNS). Genetic and environmental factors along with increases in innate (endogenous) CNS excitatory controls and decreases in inhibitory controls are also believed to contribute to the evolution of chronic pain (Marchand). Evidence-based research suggests that when acute pain does not resolve within a few months, continued activation of nerves that transmit pain (nociceptors) may result in changes in the spinal cord and brain (CNS changes) that can eventually lead to the development of chronic pain (Apkarian; Jayson). This knowledge of CNS changes due to prolonged pain may help to explain the disproportionate and non-dermatomal presentation of chronic pain and may help in the diagnosis and treatment of the individual.

Chronic pain syndrome refers to persistent pain that usually has no identifiable source and is associated with abnormal illness behaviors, including expressions of pain (moaning, groaning, gasping, or grimacing) that are grossly disproportional to any underlying cause, substance abuse involving prescription drugs, non-prescription drugs and alcohol; self-imposed prolonged excessive disuse; self-limitation of social and recreational activities; and a self-perception of total occupational disability.

Chronic pain syndrome is complex and involves multiple factors, but should be considered if a person does not respond to appropriate medical care within a reasonable time frame or if the person's pain behavior greatly exceeds the usual response to a specific disorder.

Incidence and Prevalence: It is estimated that about 35% of the American population has some degree of chronic pain, and up to 50 million Americans are partially or totally disabled due to chronic pain (Singh). Pain is the most frequent complaint leading individuals to seek medical care. Because pain is considered a symptom rather than a diagnosis, there are no valid incidence figures available for chronic pain itself.

Source: Medical Disability Advisor



Causation and Known Risk Factors

Chronic pain is reported more frequently in women than men. There is no racial predilection for chronic pain. Risk for chronic pain syndrome is increased in individuals with psychological problems such as major depression, somatization disorder, or hypochondriasis.

Source: Medical Disability Advisor



Diagnosis

History: Individuals with chronic pain syndrome describe persistent pain with subjective symptoms disproportionate to their objective findings. Individuals with chronic pain syndrome often have a history of prescription or non-prescription drug abuse, alcohol abuse, treatment by multiple medical professionals, extensive diagnostic testing and treatment, psychological disorders, and self-limitations in personal and occupational activities of daily living. A thorough history will include assessment of major organ systems, including musculoskeletal, reproductive, gastrointestinal, and urologic systems. The use of standardized questionnaires can be very helpful in gathering information about the location, quality, and severity of pain, as well as its effects on sleep and on the individual’s level of function. Risk assessment questionnaires are used as a part of history to verify the psychological and dependency risks in setting of pain management. Physicians may assess the individual for Sternbach’s 6 D’s of CPS (dramatization of complaints, drug misuse, dysfunction, dependency, depression, and disability) to establish the diagnosis.

Physical exam: Individuals with chronic pain syndrome can have normal physical examinations with no evidence of neurologic, musculoskeletal, or other impairment. Individuals with chronic pain syndrome usually exhibit expressions of pain, such as moaning, groaning, gasping, or grimacing, that are inconsistent with the absence of medical impairment. Individuals with this syndrome often exhibit so-called non-organic findings, such as little or no active range of motion but normal passive range of motion.

Tests: Individuals with chronic pain syndrome may have no abnormalities identified on diagnostic testing. However, routine blood tests and neurologic evaluation may be ordered to investigate possible underlying conditions. Psychological testing may be done, particularly if organic diseases have been excluded. A chronic pain patient should be thoroughly and periodically investigated as should any other patient. Explaining all current and future conditions of a patient by only one diagnosis of chronic pain syndrome may be misleading and dangerous.

Source: Medical Disability Advisor



Treatment

In persons with chronic pain syndrome, the focus of treatment should be on management rather than cure. The goals should be clearly defined and articulated. Goals include an increase in functional capacity and a decrease in dependencies on medication and medical providers. Abnormal illness behavior usually can be diminished. Return to the work force is highly desirable but depends on many variables, including character traits, personality, ethnic and cultural background, the presence of support systems, motivation, and prior job satisfaction. Effective management is based upon rehabilitation, behavior modification and therapy. Therapeutic measures for chronic pain can include physical therapy, occupational therapy, recreational therapy, interventional treatments (such as nerve blocks, nerve ablations, spinal surgeries and stimulation), psychological therapy, biofeedback, cognitive behavioral therapies, and medications including analgesics, antidepressants, anticonvulsants, and nonsteroidal anti-inflammatory drugs.

Source: Medical Disability Advisor



ACOEM

ACOEM's Practice Guidelines, the gold standard in effective medical treatment of occupational injuries and illnesses, are provided in this section to complement the disability duration guidelines.*
 
Chronic Pain
 
* The relationship between the MDGuidelines (MDA) content and ACOEM's guidelines is approximate and does not always link identical diagnoses. The user should consult the diagnostic codes in both guidelines, as well as the clinical descriptions, before assuming an equivalence.

Source: ACOEM Practice Guidelines



Prognosis

The prognosis for individuals with chronic pain syndrome has not been adequately defined in scientifically valid outcome studies. However, individuals fitting the criteria for chronic pain syndrome are likely to have a poor prognosis.

Source: Medical Disability Advisor



Complications

Complications may be related to the secondary gain factors that reinforce chronic pain syndrome, including a life structured around disability, treatment by multiple medical professionals, extensive diagnostic testing and treatment, treatment with prescription narcotic medication and other addictive drugs, relief from occupational activities, attention and support of spouse and family, and financial compensation. Comorbidity with other conditions like sleep disorders or depression can increase the chance of complications.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Although individuals with chronic pain syndrome self-limit their occupational activities, there may be no objective medical basis for work restrictions or accommodations. Furthermore, prescribed work restrictions or accommodations can reinforce the individual's self-perception of incapacity, thereby prolonging the duration of this syndrome.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • How was the diagnosis of chronic pain syndrome established?
  • Does individual fit the diagnostic criteria of Sternbach's 6 D’s?
  • Have alternative explanations for individual's symptoms been investigated?
  • Has an underlying major organ system disease been identified?
  • Has psychological testing been done?
  • Has substance abuse (or the risk of it) been confirmed?
  • Is this a somatoform disorder?
  • Is this a factitious disorder?
  • Is this malingering?

Regarding treatment:

  • Have physical therapy, occupational therapy, or recreational therapy been employed?
  • Has mobilization, stretching and strengthening been employed?
  • Has behavioral modification, including operant conditioning and relaxation therapy, been employed?
  • Has cognitive therapy been employed?
  • Have nerve blocks, spinal cord stimulation, or intrathecal morphine pumps been employed?
  • Has treatment reinforced the presence of chronic pain syndrome (treatment by multiple medical professionals, extensive diagnostic testing and treatment, treatment with narcotic medication and other addictive drugs)?

Regarding prognosis:

  • Have psychosocial factors, such as family and workplace dynamics, been considered?
  • Has individual responded favorably to use of nerve blocks, spinal cord stimulation or intrathecal morphine pumps?

Source: Medical Disability Advisor



References

Cited

Apkarian, Vania A., et al. "Chronic Back Pain is Associated with Decreased Prefrontal and Thalamic Gray Matter Density." Journal of Neuroscience 24 6 (2004): 10410-10415. The Journal of Neuroscience. Society for Neuroscience. 13 Feb. 2009 <http://www.jneurosci.org/cgi/content/abstract/24/46/10410>.

Jayson, M. "Mechanisms Underlying Chronic Back Pain." BMJ 309 (1994): 681-682. bmj.com. 13 Feb. 2009 <http://www.bmj.com/cgi/content/full/309/6956/681>.

Marchand, Serge. "The Physiology of Pain Mechanisms: From the Periphery to the Brain." Rheumatic Disease Clinics of North America 24 2 (2008): 285-309. MD Consult. Elsevier, Inc. 5 Feb. 2009 <www.mdconsult.com/das/article/bidy/119172771-4.htm>.

Singh, Manish K., and Jashvant Patel. "Chronic Pain Syndrome." eMedicine. Eds. Martin K. Childers, et al. 21 Nov. 2004. Medscape. 13 Feb. 2009 <http://emedicine.medscape.com/article/310834-overview>.

Source: Medical Disability Advisor






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