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.

Degeneration, Lumbar Intervertebral Disc


Related Terms

  • DDD
  • Degenerative Disc Disease (DDD)
  • Low Back Pain
  • Lumbar Disc Disease

Differential Diagnosis

Specialists

  • Chiropractor
  • Neurologist
  • Neurosurgeon
  • Occupational Therapist
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Preventive Medicine Specialist
  • Rheumatologist

Comorbid Conditions

Factors Influencing Duration

Individual's age, occupation, aerobic fitness level, and severity of symptoms may all influence the length of disability. The presence of concomitant chronic illness and / or psychosocial factors may affect length of disability.

Medical Codes

ICD-9-CM:
722.52 - Lumbar or Lumbosacral Disc Degeneration
722.73 - Lumbar Disc Disorder with Myelopathy

Overview

© Reed Group
Degeneration of a lumbar disc describes the gradual, age related loss of mechanical properties of the semi-rigid structures (intervertebral discs) that separate and cushion the bony column (vertebrae) in the lumbar spine. Consisting of 5 vertebrae, L1 through L5, the lumbar spine is in the low back between the thoracic spine and the sacrum. The discs are designated either by naming based on both the vertebra above and the vertebra below, or less commonly by the name of just the vertebra above. Thus, the lowest disc is named the L5-S1 disc, or less frequently just as the L5 disc. Lumbar disc degeneration usually occurs first between the fourth and fifth lumbar vertebrae or between the fifth lumbar and first sacral vertebrae (Hoff 956).

Intervertebral disc degeneration, especially in the lumbar spine, begins most commonly in people in their second decade of life (Kjaer). Whether the degenerating disc is a cause of back pain is controversial. Doctors who attribute back pain to degenerating discs frequently use the term "degenerative disc disease" (DDD). However, scientific evidence that the aging changes ("degeneration") seen on imaging are responsible for (correlate with) back pain is not present, and thus the term "non-specific low back pain" is the more prevalent term used instead of degenerative disc disease. Intermittent episodes of back pain may occur months or years before more persistent low back pain or leg pain. Pain may be exacerbated by flexion of the lumbar spine during heavy exertion, repetitive bending, twisting, or heavy lifting. However, it has been demonstrated that minor trauma does not cause either serious chronic low back pain and disability, or new MRI findings (Carragee, "Minor Trauma"; Carragee, "First-time Episodes"). The rate at which individuals develop aging ("degenerative") change on imaging is largely genetically determined, and exposures to activities such as occupation and recreation have very little effect on the rate of spinal aging (Battié).

As in the cervical and thoracic spines, lumbar disc degeneration occurs naturally with aging. Discs have a soft, gelatin-like material in the center (nucleus pulposus) that remains soft because of its high water content (about 80% in the young spine). However, the water content decreases with age, which causes the disc to change appearance on MRI (decreased signal or T2 weighted images, or become "black") and to lose some of its elasticity, restricting its function as a shock absorber. The disc space narrows as degeneration occurs, placing stress on the other joints of the vertebrae (facet joints), and this leads to degeneration of the facet joints (osteoarthritis change). Disc displacement (herniation) may occur secondary to disc degeneration when the nucleus pulposus protrudes abnormally beyond the fibrous ring into the spinal canal, often pressing on spinal nerves and causing changes in sensory, motor, and reflex function (radiculopathy).

Usually, the precise cause of back pain cannot be identified, but because pain and degeneration coexist, the pain is attributed to the degenerative changes by some physicians.

Several things may contribute to the pain often attributed to degenerative disc disease. The discs may lose water and become less flexible. Small tears in the tough ring of cartilage that makes up the outer disk (annulus fibrosis) may allow the jelly-like material of the nucleus pulposus to protrude from the disc space (herniate) and compress the nerve root. Bone spurs (osteophytes) grow slowly over time, and the spinal canal may narrow and compress the nerves that run through it. Any of these possibilities may cause pain of varying duration and intensity. Symptoms attributed to DDD by some physicians will generally vary according to the location and degree of vertebral compression and the activity level of the individual. However, symptoms do not always match up with imaging changes. The presence of diseases that affect the spine or adjacent organs may refer pain to the lower back and legs and may complicate diagnosis of why a person has back pain.

Incidence and Prevalence: Over the course of a person's life there is a 60% to 90% chance that an individual will suffer an episode of low back pain; the likelihood that it might occur in any given year is 5%. According to the National Center for Health Statistics, low back pain accounts for 13 million visits to the doctor each year. With 2.4 million people excused from work during any period, low back pain is the single greatest reason for lost productivity in the US (Patel).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Aging is a risk factor for lumbar disc degeneration. In individuals of all ages undergoing MRI, 30% of those without symptoms showed disc degeneration; among individuals 60 years of age and older, 57% had abnormalities (Patel). The tendency to develop lumbar disc degeneration at an earlier age appears to be genetic. Smoking has been shown to increase the risk and rate of disc degeneration.

Source: Medical Disability Advisor



Diagnosis

History: The history of individuals with pain attributed to degenerative discs by some physicians has nothing to distinguish it from the history of back pain in those other physicians diagnose with non-specific low back pain. Pain due to systemic illnesses may be recognizable, but musculoskeletal back pain patients have no unique symptoms in their history to permit recognition of the source of the pain.

Physical exam: The exam is often unremarkable. Limited range of motion may or may not be present. Palpation of the lumbar spine may cause pain, although tenderness in the low back area away from the spine is usually a behavioral sign. The neuromuscular exam is directed at excluding any symptoms or signs of spinal nerve involvement.

Tests: Plain x-rays will show the narrowing of the disc space and some osteophyte formation on the vertebral bodies as examples of age-related changes. These changes are usually not the cause of the symptoms. Flexion-extension plain x-rays are used to detect spinal instability, which is uncommon and, when seen, almost always occurs in elderly women. Further testing is not indicated unless there are signs of spinal nerve irritation or systemic disease. MRI studies are currently the gold standard for specific diseases that may be present (such as spinal infection, tumor, or inflammatory arthritis). Discography is a controversial test with no clear demonstration in the literature that it can reliably identify the source of back pain or lead to an effective treatment. Discography has been implicated as causing permanent damage in the discs that are tested, so its use is controversial at best (Carragee 2009).

Source: Medical Disability Advisor



Treatment

Conservative treatment with medication such as nonsteroidal anti-inflammatory agents (NSAIDs), and an exercise program or manipulation is usually the initial treatment. The treatment regimen should include aerobic exercise, since decreased aerobic fitness is a risk factor for recurrence of symptoms.

Recovery may be improved by a few sessions of manipulation, followed by instruction on safe postures and positions. The individual should be encouraged to resume activities that can be tolerated (Bigos).

Surgery is uncommonly performed but may be indicated in cases of chronic, significant back pain without radicular symptoms and degeneration limited to one or two disc levels. The individual must be made aware that surgery does not provide a cure and, at best, may relieve some of the back and leg symptoms. In highly selected cases of back pain that have not responded to conservative measures in patients with instability proved by x-rays, and without psychosocial confounders, fusion of the affected vertebrae is sometimes performed, although demonstration of effectiveness is lacking in the literature. Artificial disc replacement has been approved, and appears to give comparable early results to fusion, although the long-term outcomes are not yet known.

Discectomy is not a consideration for disc degeneration. Discectomy is only indicated for disc herniations with nerve root compression.

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.*
 
Low Back Disorders
 
* 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

Lumbar disc degeneration is chronic and irreversible. Acute episodes of back pain may resolve in a few weeks. Much of the outcome depends on the activity level of the individual. In general, individuals with heavy jobs have more difficulty functioning during episodes of back pain than individuals with light jobs. The prognosis is very good following conservative treatment in a large majority of individuals. Almost half of those afflicted with low back pain will be free of discomfort within 1 week, and 90% will recover between 6 and 12 weeks (Patel). Estimates vary somewhat, but within 2 years of an episode, 60% to 85% will experience a recurrence (Patel). However, individuals who do not follow a treatment regimen that includes strength-building exercises tend to have a poorer outcome, with more frequent and prolonged recurrence of back pain. If back pain attributed to degenerative disc disease has kept a person from working for over a year, there is only a 25% chance that the person will return, and after 2 years, that likelihood essentially drops to zero (Patel).

According to one prospective, observational study, among individuals with acute low back pain, the outcomes are similar whether they receive care from chiropractors, primary care practitioners, or orthopedic surgeons (Carey).

Source: Medical Disability Advisor



Rehabilitation

Individuals with back pain attributed by their physicians to degeneration of the lumbar intervertebral discs may benefit from rehabilitation to decrease pain and regain mobility and strength of the spine. It should be recognized that degeneration of a disc is a natural component of aging, and may or may not cause symptoms. Therapy to reduce symptoms, followed by spinal exercises, may be sufficient for mild cases. More involved rehabilitation is required for severe symptoms. Passive intervention should be time-limited. Active exercise should be started as soon as tolerated. Rehabilitation will be based upon the duration of time from the onset of symptoms. The goal of rehabilitation is to promote an active lifestyle and regular participation in an exercise program (Malmivaara).

Acute Phase (up to 1 week): Therapy is not usually recommended in the acute phase of low back pain, other than self-application of ice or heat at home.

Subacute Phase (3 to 12 weeks): A therapist should instruct the individual in an exercise program that will help maintain the individual's well-being. Physical therapy will include modalities such as moist heat and electrical stimulation to control pain in order to promote physical activity. During this phase, the workplace should undergo an ergonomic evaluation so that changes may be implemented to assist the employee in returning to work. Toward the later stages of this phase, if the individual shows a lack of or slow progress, a health psychologist should evaluate the individual to determine whether or not there are signs of psychological distress secondary to the injury (Kendall). There is evidence that a multidisciplinary treatment approach can be effective in treating these individuals and returning them to a full level of activity (Loisel).

Chronic Phase (more than 12 weeks): The individual should continue to be educated in functional exercises and proper body mechanics. A short course of cognitive pain management may be beneficial. There is evidence that, as with those in the subacute phase, those in the chronic phase may recover through a multidisciplinary treatment approach, returning to a full level of activity. An ergonomic evaluation with modifications may enable the individual's return to work and reduce the risk of re-injury. Vocational services should be available for individuals who cannot return to their previous job title or do not have a job to which to return (van Tulder).

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistDegeneration, Lumbar Intervertebral Disc
ChiropractorUp to 3 visits within first week of onset
Clinical PsychologistUp to 12 visits within 6 weeks
ErgonomistUp to 2 visits within 8 weeks
Occupational TherapistUp to 12 visits within 6 weeks
Physical TherapistDaily up to 6 weeks
Vocational CounselorUp to 3 visits within 6 weeks
Clinical PsychologistUp to 2 visits within 6 weeks of onset
Physical TherapistUp to 12 visits within 6 weeks
Surgical
SpecialistDegeneration, Lumbar Intervertebral Disc
Physical TherapistUp to 6 visits within 6 weeks
Note on Surgical Guidelines: Rehab usually begins after tissue healing, about 6 to 8 weeks after surgery.
As part of multidisciplinary intervention (work conditioning).
The table above represents a range of the usual acceptable number of visits for uncomplicated cases. It provides a framework based on the duration of tissue healing time and standard clinical practice.

Source: Medical Disability Advisor



Complications

Severe degenerative changes may cause degenerative spinal stenosis with compression of the nerve root and may result in weakness or paralysis of the affected muscle group, along with loss of sensation in the lower limb(s).

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Temporary work restrictions should include avoidance of heavy lifting, twisting motions, prolonged sitting or standing, and activities that involve heavy vibration (such as driving large earth moving vehicles and using construction equipment such as jackhammers). Individuals may benefit from rest periods. Use of pain medication and muscle relaxants can affect dexterity and alertness. Safety issues will need to be evaluated. Work-hardening programs and worksite evaluations are beneficial to many individuals and may allow for earlier return from disability.

Source: Medical Disability Advisor



Maximum Medical Improvement

By definition “degenerative disc disease” (aging change) occurs over long time periods and this is not an acute injury. However, in workers’ compensation, workers will allege their pain begins during a work activity, and physicians who use this diagnosis will state the work activity “aggravated the degenerative changes.” There is no scientific way to prove or disprove this claim, so the diagnosis of work-aggravated-degenerative-disc disease is at times in the workers’ compensation system. By 112 days after pain onset, the condition is unlikely to change, absent surgical treatment. Thus MMI can be established usually by 112 days after the “aggravating incident.”

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:

  • Were x-rays done? What were the findings?
  • Was MRI performed? What were the findings?
  • Has a psychologist or psychiatrist assessed the individual for mental disorders (including personality disorders) that are associated with delayed recovery?
  • Has the individual been asked if a different supervisor was appointed, could he or she then return to his or her usual job? (detects interpersonal conflict, rather than ergonomic tasks, as the barrier to return to work.)

Regarding treatment:

  • Did individual respond to conservative therapy?
  • Is individual taking nonsteroidal anti-inflammatory drugs? Muscle relaxants? Opioids?
  • Does individual have a home-exercise program that includes some aerobic activity?
  • How long has individual had intractable back pain?
  • Is individual a candidate for surgery?

Regarding prognosis:

  • Was individual active and cooperative in physical therapy?
  • Has individual incorporated exercises that improve posture, flexibility, and strength into the home-exercise program?
  • Are chronic conditions such as severe scoliosis, a narrowed spinal canal, osteoporosis, or osteoarthritis present?
  • Is the individual improving, static, or worsening over time?

Source: Medical Disability Advisor



References

Cited

Battié, M. C. , et al. "The Twin Spine Study: Contributions to a changing view of disc degeneration." Spine 9 (2009): 47-59.

Bigos, S., et al. "Acute Low Back Problems in Adults." Clinical Practice Guidelines. 14th ed. Rockville, MD: Agency for Healthcare Policy Research (AHCPR), 1994.

Carey, T. S., et al. "The Outcomes and Costs of Care for Acute Low Back Pain Among Patients Seen by Primary Care Practitioners, Chiropractors, and Orthopedic Surgeons." New England Journal of Medicine 333 (14) (1995): 913-917. National Center for Biotechnology Information. National Library of Medicine. 16 Dec. 2008 <PMID: 7666878>.

Carragee, E. J. , et al. "Does Discography Cause Accelerated Progression of Degenerative Changes in the Lumbar Disc: A Ten-Year Matched Cohort Study." Spine 34 (21) (2009): 2338-2345.

Carragee, E., et al. "Are First-time Episodes of Serious Low Back Pain Illness Associated with New MRI Findings?" Spine 6 6 (2006): 624-635.

Carragee, E., et al. "Does Minor Trauma Cause Serious Low Back Pain Illness?" Spine 31 25 (2006): 2942-2949.

Gross, D. P. , and M. C. Battié. "Functional Capacity Evaluation Performance Does Not Predict Sustained Return to Work in Claimants with Chronic Back Pain." Journal of Occupational Rehabilitation 15 (3) (2005): 285-294.

Hall, H. , et al. "Effect of Discharge Recommendations on Outcome." Spine 19 (18) (1994): 2033-2037.

Hoff, Julian T. "Intervertebral Disc Disease." Current Surgical Diagnosis & Treatment. Eds. L. W. Way and Gerald M. Doherty. 11th ed. New York: McGraw-Hill, 2004. 952-958.

Kendall, N., S. J. Linton, and C. J. Main, eds. "Guide to Assessing Psychological Yellow Flags in Acute Low Back Pain." Risk Factors for Long-Term Disabilities and Work Loss. Wellington, New Zealand: The National Health Committee, 1997.

Kjaer, P. , et al. "An Epidemiologic Study of MRI and Low Back Pain in 13-Year Old Children." Spine 30 (7) (2005): 798-806.

Loisel, P., et al. "A Population-based, Randomized Clinical Trial on Back Pain Management." Spine 22 24 (1997): 2911-2918. National Center for Biotechnology Information. National Library of Medicine. 19 Dec. 2004 <PMID: 9431627>.

Malmivaara, A., et al. "The Treatment of Acute Low Back Pain--Bed Rest, Exercises, or Ordinary Activity?" New England Journal of Medicine 332 6 (1995): 351-355. National Center for Biotechnology Information. National Library of Medicine. 19 Dec. 2004 <PMID: 7823996>.

Patel, Rajeev K., and Curtis W. Slipman. "Lumbar Degenerative Disc Disease." eMedicine. Eds. J. Michael Wieting, et al. 1 Oct. 2004. Medscape. 10 Sep. 2004 <http://emedicine.com/pmr/topic67.htm>.

van Tulder, M. W., et al. "Behavioral Treatment for Chronic Low Back Pain: A Systematic Review within the Framework of the Cochrane Back Review Group." Spine 26 3 (2001): 270-281. National Center for Biotechnology Information. National Library of Medicine. 19 Dec. 2004 <PMID: 11224863>.

Williams, Keith D., and Ashley L. Park. "Lumbar Disc Disease." Campbell's Operative Orthopaedics. Eds. S. Terry Canale and James H. Beaty. 11th ed. Philadelphia: Mosby Elsevier, 2008. 2199-2216.

General

Williams, Keith D., and Ashley L. Park. "Lumbar Disc Disease." Campbell's Operative Orthopaedics. Eds. S. Terry Canale and James H. Beaty. 11th ed. Philadelphia: Mosby Elsevier, 2008. 2199-2216.

Source: Medical Disability Advisor






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