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.

Spondylolysis, Lumbar Region


Related Terms

  • Fracture of Lumbar Vertebrae

Specialists

  • Neurosurgeon
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist

Comorbid Conditions

Factors Influencing Duration

The number and severity of symptoms and frequency of occurrence may influence the length of disability. Occupational situations that require repetitive loading and bending of the spine can increase the likelihood of periods of disability from associated pain.

Medical Codes

ICD-9-CM:
756.1 - Anomalies of Spine
756.10 - Anomaly of Spine, Unspecified
756.11 - Spondylolysis, Lumbar Region; Prespondylolisthesis (Lumbosacral)

Overview

© Reed Group
Spondylolysis is a break (fracture) in the arch of the rear (posterior) segment of the vertebra, called the pars interarticularis. In 95 percent of individuals, spondylolysis affects the fifth lumbar vertebra (L5) (Weinberg). Occasionally the fourth lumbar (L4) vertebra is affected, but rarely the remaining lumbar and the thoracic vertebrae.

The lumbar vertebrae are stacked one on top of the other with the hook-shaped posterior portion forming a joint (facet) on either side of the midline. Vertebrae are separated by shock-absorbing discs made of cartilage and held together with tough fibrous bands of ligaments. Muscles running along the length of the spine and between the vertebrae help to stabilize the vertebral column.

The fracture may be the result of a traumatic episode (uncommon) or repeated stress across the area (stress fracture) and may result in the vertebra sliding or slipping forward, a condition called spondylolisthesis. (Spondylolisthesis may occur in the absence of spondylolysis, in degenerative conditions, and after surgery.) Research shows that the bone fracture occurring in spondylolysis may be associated with an inherited defect in the bone that connects the upper joint of one vertebra to the lower joint of another vertebra (pars interarticularis).

Incidence and Prevalence: In the US, the incidence of spondylolysis is 3% to 7%. Among athletes in certain sports, the incidence is markedly higher, at 23% to 62%. Men are 2 to 4 times more likely to develop the condition. It occurs in both children and adults, with an incidence rate at age 6 years of 4.4% (Weinberg). Acute traumatic spondylolysis is uncommon.

Source: Medical Disability Advisor



Causation and Known Risk Factors

Genetics, overuse, and aging increase the risk of spondylolysis. Individuals with spina bifida occulta are at increased risk. Amateur and professional athletes are also at an increased risk, especially those who participate regularly in sports and activities that require repetitive flexion-extension movements, such as gymnastics, dance, wrestling, football, and swimming, especially breast and butterfly stroke (Spinelli).

Source: Medical Disability Advisor



Diagnosis

History: Individuals with established fractures may experience little or no pain or other symptoms. Previously asymptomatic individuals with spondylolysis may report acute pain in the aftermath of a recent traumatic event. If the fracture is not a recent one, the pain may be felt deep within the lower back and radiate to the buttock and thigh on the affected side. The pain may be relieved with rest.

Physical exam: A complete musculoskeletal exam may reveal limitations in lumbar flexibility and tight hamstring muscles. Neurologic exam is usually normal. The forward bend test may detect an abnormal lateral curvature of the spine (scoliosis) since individuals with spondylolysis may also have scoliosis. Palpation of the back may reveal tenderness at the lumbosacral junction, the site of most cases of spondylolysis.

Tests: Plain radiographs of the lower back (both lateral and oblique views) are the most common studies used to demonstrate spondylolysis. CT scan may be helpful to visualize the suspected bony defect, which is often less apparent on MRI. Single-photon emission computed tomography (SPECT) bone scintigraphy may be used to further evaluate individuals when plain radiographs prove negative or inconclusive; however, this test is positive only in relatively recent fractures and is therefore less valuable as a diagnostic tool in adults.

In some cases, CT scan and MRI can help define nerve root impingement (MRI is better at detection). MRI can also define the status of the disc at and just above the level of slippage (where disc herniations are more common). Electromyography (EMG) and nerve conduction studies may be used to check nerve function when signs and symptoms suggest nerve root involvement.

Source: Medical Disability Advisor



Treatment

Acute fractures, uncommon in the adult population, are treated with immobilization using a semi-rigid brace and cessation of all activities that cause flexion and extension of the lumbar spine. Individuals with painful spondylolysis, especially when a stress fracture is suspected and the region is "hot" on bone scan, may benefit from a period of immobilization in a body jacket or back brace. Individuals are usually required to wear the braces for 3 to 6 months, and are monitored for fracture healing. Some physical activity, appropriately modified and limited, is recommended while wearing the brace.

Conservative treatment to control pain in symptomatic spondylolysis includes heat, physical therapy, and medication.

Any post-treatment education of the individual should discuss prevention of injury. Muscle-strengthening programs should be included after the acute symptoms subside. Prescribed exercises include those that attempt to increase the strength of the abdominal musculature and the flexibility of the lumbar extensors, hamstring, and quadriceps muscles. Walking and cycling are appropriate exercises during rehabilitation.

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

Acute fractures that are recognized and treated may heal without complication. For nonacute but symptomatic spondylolysis, conservative treatment to control pain (ice and heat, physical therapy, and medication) is generally successful.

Source: Medical Disability Advisor



Rehabilitation

Individuals with spondylolysis may benefit from rehabilitation to decrease pain, as well as to regain mobility and strength to that particular region of the spine. The underlying etiology should be considered prior to initiating treatment. If the underlying cause is a fracture, see Fracture, Lumbosacral Spine (Without Spinal Cord Injury).

The goal of rehabilitation is to promote an active lifestyle and regular participation in an exercise program. While the symptoms are acute, individuals should be introduced to gentle trunk exercises and instructed in comfortable postures and positions that are safe for the spinal structures. Therapy will include modalities such as moist heat and electrical stimulation to control pain in order to promote physical activity. The individual should be encouraged to resume activities as tolerated.

When acute symptoms subside, an exercise program is taught that will promote the individual's full function and well being. The exercise program should focus on general conditioning, as well as strengthening, coordination, stabilization and flexibility of the trunk (McNeely).

In addition to undergoing supervised rehabilitation, the individual should be instructed in a home exercise program to be practiced daily and continued independently after the completion of rehabilitation. Common clinical practice dictates the use of bracing in the early stage for a limited time to control the individual's mobility and pain (Standaert). In some instances this condition may require surgical intervention, in which case treatment will be based on the postoperative protocol of the surgeon.

The individual should be educated in proper body mechanics, and the work place should undergo an ergonomic evaluation so that changes may be implemented to assist the employee's return to work. 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.

If the individual does not respond to the rehabilitation, a psychologist may evaluate the individual to determine whether or not there are signs of psychological distress secondary to the condition. There is evidence that a multidisciplinary treatment approach can be effective in treating individuals who do not respond to conservative treatment (See Low Back Pain).

For further information about the management of this condition and rehabilitation outcome, please refer to "Spondylolysis and Spondylolisthesis" (Molinari).

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistSpondylolysis, Lumbar Region
Physical TherapistUp to 15 visits within 6 weeks
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

Defects on both sides of the vertebra (bilateral) are likely to lead to a sliding or slipping forward of the vertebrae (spondylolisthesis). This does not occur with defects on one side of the vertebra (unilateral).

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

For individuals with acute fractures, overhead work, arching the back, and heavy or unassisted lifting and carrying may have to be avoided. Restricting the frequency and amount of weight involved is prudent. Pushing heavy objects could aggravate the condition.

Individuals who are prescribed a back brace may require sedentary work during the 3- to 6-month period they are wearing the brace.

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:

  • Has diagnosis of lumbar spondylolysis been confirmed?
  • Has individual experienced any complications?
  • Does individual have an underlying condition that may affect recovery?

Regarding treatment:

  • Is condition the result of a fracture?
  • Were conservative measures effective in relieving pain?
  • Is pain interfering with functional ability?
  • Would individual benefit from additional physical therapy?

Regarding prognosis:

  • Does pain at the fracture site persist despite treatment?
  • Have x-rays verified complete bone union?
  • Can individual return to work with accommodations?
  • Would a back brace be useful?

Source: Medical Disability Advisor



References

Cited

McNeely, M. L., G. Torrance, and David J. Magee. "A Systematic Review of Physiotherapy for Spondylolysis and Spondylolisthesis." Manual Therapy 8 2 (2003): 80-91. National Center for Biotechnology Information. National Library of Medicine. 25 Sep. 2008 <PMID: 12890435>.

Molinari, R., and Lawrence Lenke. "Spondylolysis and Spondylolisthesis." The Adult and Pediatric Spine. Eds. J. W. Frymoyer and S. W. Wiesel. 3rd ed. 2 vols. Philadelphia: Lippincott, Williams & Wilkins, 2004. 399-423.

Spinelli, James, and James Rainville. "Lumbar Spondylolysis and Spondylolisthesis." Essentials of Physical Medicine and Rehabilitation. Eds. Walter R. Frontera, Julie K. Silver, and Thomas Rizzo. 2nd ed. Philadelphia: Saunders, Elsevier, 2008.

Standaert, C. J., and S. A. Herring. "Spondylolysis: A Critical Review." British Journal of Sports Medicine 34 6 (2000): 415-422. National Center for Biotechnology Information. National Library of Medicine. 25 Sep. 2008 <PMID: 11131228>.

Weinberg, Eric P. "Spondylolysis." eMedicine. Ed. Jacqueline C. Hodge. 7 Jan. 2008. Medscape. 18 Feb. 2009 <http://emedicine.medscape.com/article/395916-overview>.

Source: Medical Disability Advisor






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