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.

Myofascial Pain Syndrome


Related Terms

  • Localized Fibromyalgia
  • Muscular Rheumatism
  • Muskelhärten
  • Myalgia
  • Myofascial Pain and Dysfunction Syndrome
  • Myofascitis
  • Myofibrositis
  • Myogelosen
  • Myogeloses
  • Regional Pain Syndrome
  • Soft Tissue Syndrome
  • Trigger Points syndrome

Differential Diagnosis

Specialists

  • Chiropractor
  • Dentist
  • Neurologist
  • Orthodontist
  • Orthopedic (Orthopaedic) Surgeon
  • Osteopath
  • Pain Medicine Physician/Pain Specialist
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Rheumatologist

Comorbid Conditions

  • Bursitis
  • Degenerative joint disease
  • Fractures
  • Hypothyroidism
  • Intervertebral disc lesions
  • Joint dysfunction
  • Spondylolisthesis
  • Subluxation and / or dislocation
  • Temporomandibular Joint (TMJ) Dysfunction
  • Tendinopathies

Factors Influencing Duration

Even proponents believe that acute cases of MPS typically resolve quickly and should not be a significant factor with respect to work loss or disability. Chronic cases are invariably associated with other musculoskeletal disorders, and in these situations length of disability is related to the underlying primary disorder. The problems individuals with MPS experience at work are related to subjective pain tolerance and not with inability or capacity to perform.

Medical Codes

ICD-9-CM:
724.2 - Lumbago; Low Back Pain; Low Back Syndrome; Lumbalgia
728.89 - Other Disorder of Muscle, Ligament and Fascia; Other; Eosinophilic Fasciitis
729.0 - Rheumatism, Unspecified, and Fibrositis
729.1 - Myalgia and Myositis, Unspecified; Fibromyositis NOS; Fibromyalgia

Overview

Myofascial pain syndrome (MPS) is a controversial diagnosis. According to the Fifth Edition of the American Medical Association (AMA) Guides, the medical community has not yet achieved consensus on how to interpret this syndrome (Cocchiarella 569). MPS is a term commonly used by some members of the health care community, while others use terms such as "myalgia" (muscle pain), or "regional pain syndrome."

MPS has different meanings to different health care providers. Proponents of the disorder believe it is a recognizable, painful pathology of skeletal muscle and / or connective tissue (Simons). Skeptics believe individuals may experience localized pain where muscles exist, but there is not necessarily a proven underlying disorder of the skeletal muscle or connective tissue (Bohr). This controversy among medical providers makes evaluating medical records from different providers complicated.

Proponents define the term MPS as any regional pain disorder that seems to emanate from the soft tissues (muscle, tendon, ligament, or connective tissue). The specific meaning they assign to MPS is that of a condition characterized by a particular referred pain pattern arising from a specific skeletal muscle(s). The diagnosis of MPS requires physical examination and palpation to identify discrete muscular "knots," also known as trigger points (TrPs), which are found within taut bands of skeletal muscle tissue.

A myofascial TrP is a hyperirritable, hypersensitive, palpable nodule that is painful upon compression and that gives rise to a characteristic pattern of referred pain. Deep palpation directly over a TrP usually reproduces the pain pattern described by the individual.

Theoretically, an individual with a palpable myofascial TrP in a specific muscle experiences vague pain at rest near the TrP, but experiences both localized pain at the point of palpation and referred pain when the TrP is palpated; the consistent location of referred pain permits recognition of the dysfunctional muscle. Proponents believe that MPS trigger points are most frequently found in axial postural muscles, but may be found in more than one location. Proponents also believe in "latent" TrPs: A latent TrP occurs in a place where the individual normally feels no pain, yet upon palpation the individual then experiences both the local and referred pain patterns.

Proponents divide MPS into two types: Primary MPS, in which the chief complaint is specific, muscular TrP pain in the absence of other musculoskeletal pathology; and secondary MPS, which is more common, and is characterized by muscular pain and TrPs associated with another primary musculoskeletal condition, such as degenerative or rheumatoid arthritis, spinal stenosis, intervertebral disc lesions, spondylolisthesis, subluxations/dislocations, and fracture.

Regardless of interpretation, MPS TrPs are different from the tender points associated with fibromyalgia syndrome, in which the individual experiences only local pain without referred pain, and the physician feels no abnormality upon palpation.

MPS is often a diagnosis of exclusion, which means that the diagnosis is confirmed when other diseases are ruled out.

Incidence and Prevalence: Due to the debatable nature of this diagnosis, no specific epidemiologic data are available on the incidence or prevalence of MPS. It is estimated that MPS is present in anywhere from 21% to 93% of individuals with regional pain complaints (Finley).

Source: Medical Disability Advisor



Causation and Known Risk Factors

There are no specific risk factors associated with MPS. Any individual with soft tissue pain may be diagnosed with MPS if seen by a physician who is a proponent of this diagnosis. MPS may occur at any age, but is diagnosed more frequently in middle age; men and women are equally affected (Finley). Individuals with postural aberrations (i.e., rounded and sloping shoulders or forward head carriage) may be at a higher risk for developing discomfort of the axial postural muscles.

Source: Medical Disability Advisor



Diagnosis

History: Most individuals diagnosed with MPS will typically report a regional pain pattern in one specific anatomical region, or at most in one quadrant of the body. However, many describe pain in various other locations when specifically questioned. Individuals often describe the pain as deep, dull, aching, and diffuse; rarely do they describe their pain as sharp, intense, or clearly localized. The individual will frequently give a history of a repetitive activity or injury that may implicate a muscular overuse or traumatic etiology of the pain syndrome.

Physical exam: Range of motion may be mildly restricted, as proponents believe that painful myofascial TrPs will typically prevent the injured muscle from fully stretching; however, skeptics attribute the mild restriction to disuse and deconditioning. Manual muscle testing may provoke pain that precludes accurate evaluation of muscle strength. Proponents believe that TrPs are palpated as tender nodules within a localized, taut band of muscle; cross fiber palpation ("snapping") of muscle tissue may elicit a local twitch response (jump sign), in which the individual may cry out or flinch from the pressure. Deep compression of the TrP nodule will often precisely reproduce painful symptoms, which proponents consider a key diagnostic criterion.

Physicians who do not subscribe to this diagnosis will usually find the physical exam to be normal, or to demonstrate only non-specific tenderness.

Tests: No laboratory or diagnostic imaging tests have been found to be useful in establishing diagnosis, or prognosis, for these individuals. Radiographs, MRI scans, and EMG/nerve conduction testing are usually normal. Functional capacity testing may show a valid or an invalid profile, and typically shows self-limitation based on subjective pain tolerance.

Source: Medical Disability Advisor



Treatment

Many treatment approaches have been advocated by MPS proponents for releasing myofascial TrP nodules, including various types of manual therapy, physical therapy, and needle injection. Manual therapies include deep pressure TrP release techniques, post-isometric relaxation, transverse friction massage, augmented stretching, and biofeedback combined with stretching and relaxation. Physical therapy modalities, applied directly over the TrP nodule, include ultrasound, electrical stimulation, and more recently "cold" laser light therapy. Needle injection is also performed directly over the TrP nodule, and appears to be clinically effective regardless of whether a “dry needling” technique is used or a substance is injected.

In addition to passive techniques applied directly over the TrP nodule, proponents believe many individuals benefit from adjunctive active therapies such as postural education, rehabilitative exercises, and modification of activities of daily living. Even skeptics rarely object to postural education and rehabilitative exercise instruction. Proponents believe that finding and correcting the key perpetuating mechanical factors that underlie the chronic nature of primary MPS is often essential to long term success and a better prognosis. Secondary MPS that is associated with other primary musculoskeletal disorders (e.g., intervertebral disc syndromes, spinal stenosis, fracture, or dislocation) may improve or resolve with treatment of the primary disorder.

Proponents believe that oral medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and muscle relaxants that have a systemic effect are neither desirable nor indicated for the focal nature of myofascial TrPs, which only involve a small region of muscle tissue. Interestingly, while these medications are generally effective for muscle pain due to acute injury or unaccustomed overuse (delayed onset muscle soreness), these medications are frequently ineffective or only marginally effective for this type of muscle pain (MPS).

Skeptics are likely to conclude that these individuals are experiencing ordinary muscle aches, and that over the counter medication, topical heat ointment, aerobic exercise, and simple stretching are all that is indicated for treatment. These physicians might endorse a few physical therapy visits for instruction in a home modality and exercise program to self-manage symptoms.

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

Proponents believe that MPS may be acute or chronic. Proponents believe that, if treated early, acute MPS characterized by myofascial TrPs that have developed in muscles subjected to acute overload or overuse typically have an excellent prognosis, and should resolve within 4 to 6 weeks of conservative treatment.

Proponents believe that chronic MPS typically involves multiple complicating factors and / or other diagnoses. For example, proponents believe that lumbar disc herniation is often associated with myofascial pain due to TrPs in the lumbar paraspinals and gluteal muscles. Yet, the reason for the poorer prognosis in this case is not believed to be the secondary myofascial TrP activity, but rather the primary disc herniation. Proponents believe that resolution of the primary cause will often lead to spontaneous resolution of the associated secondary MPS.

Source: Medical Disability Advisor



Rehabilitation

The goal of rehabilitation for individuals with MPS is to preserve function and promote independence. Individuals with MPS may benefit from short term outpatient physical therapy that includes active stretching and postural strengthening exercises performed regularly, in conjunction with a home exercise program.

Proponents believe that treatment of MPS involves two components: The first component involves deactivation of the TrP nodules by directly treating the taut band and muscle nodule. This can be accomplished by needle injection, deep manual pressure, physical therapy modalities, and / or stretching techniques. The second component, which should be addressed concurrently, is identifying and eliminating any perpetuating factors in the individual's posture, activities of daily living, or work habits that might be causing repetitive strain of the offending muscle(s) to help minimize risk for recurrence.

Once focal areas containing TrP nodules have been treated and released, the affected muscle may require stretching and strengthening techniques to reestablish normal muscle tone. Treatment for MPS should not require lengthy rehabilitation beyond a standard 4 to 6 week physical therapy program. If an individual does not respond within this time frame, reexamination by a physician is necessary to rule out other possible diagnoses.

Source: Medical Disability Advisor



Complications

Minor complications can arise from treatment, such as bruising and ecchymosis from excessive manual pressure or massage techniques, as well as post needle injection. Patients who are taking anticoagulant or steroid medications should be treated with caution when using myofascial treatment procedures.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Unless MPS is associated with other more complicated diagnoses, there is typically no need for restrictions or accommodations of job duties. Occasionally, those with MPS benefit from minor modification in the workplace to prevent recurrence if the condition is associated with a muscular repetitive strain etiology. Ergonomic assessment of computer workstations may be helpful. Individuals who perform repeated bending and lifting tasks should be educated in proper body mechanics.

During the acute phase, making allowances for stretching breaks during the work day can facilitate personal responsibility and self-reliance. Occasional use of orthopedic supports or braces may help mitigate the effects of muscular strain and facilitate a return to work, but should not be used routinely in order to prevent dependency.

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:

  • Are there undiagnosed psychiatric conditions?
  • Is there unusual psychosocial stress currently in the life of this patient?
  • Have other musculoskeletal disorders been ruled out?
  • If other musculoskeletal diagnoses coexist with the myofascial pain diagnosis, is the myofascial pain secondary to an underlying primary pain source?
  • In cases of widespread pain with purported multiple muscular trigger points, have other systemic diseases been ruled out?
  • Is the clinician confusing the hyperalgesic tender points of fibromyalgia syndrome with trigger point nodules and taut bands found in myofascial pain disorders?

Regarding treatment:

  • Has a specific manual soft tissue treatment technique been used directly over the trigger point nodules?
  • Is the clinician well versed in myofascial treatment techniques?
  • Is individual compliant with physical therapy?
  • With chronic cases that are resistant to manual techniques, has needle injection been tried?

Regarding prognosis:

  • Have all perpetuating factors been identified and eliminated through ergonomic evaluation, postural correction, and rehabilitative exercise?
  • Is individual compliant with elimination of these perpetuating factors?
  • Is there another musculoskeletal pain disorder that is complicating the prognosis, considering that primary myofascial pain has an excellent prognosis?

Source: Medical Disability Advisor



References

Cited

Bohr, T. W. "Fibromyalgia Syndrome and Myofascial Pain Syndrome: Do They Exist? In Malingering and Conversion Reactions." Neurologic Clinics 13 2 (1995): 365-384.

Cocchiarella, L., and G. B. Andersson. Guides to the Evaluation of Permanent Impairment. 5th ed. Chicago: AMA Press, 2000.

Finley, Jennifer E. "Myofascial Pain." eMedicine. Eds. Martin K. Childers, et al. 21 Jul. 2004. Medscape. 21 Mar. 2005 <http://emedicine.com/pmr/topic84.htm>.

Nice, D., et al. "Intertester Reliability of Judgments of the Presence of Trigger Points in Patients with Low Back Pain." Archives of Physical and Medical Rehabilitation 73 10 (1992): 893-898.

Simons, D. G., J. G. Travell, and L. S. Simons, eds. "Upper Half of Body." Myofascial Pain and Dysfunction: The Trigger Point Manual. Baltimore: Williams & Wilkins, 1999.

Wolfe, F., et al. "The Fibromyalgia and Myofascial Pain Syndromes: A Preliminary Study of Tender Points and Trigger Points in Persons with Fibromyalgia, Myofascial Pain Syndrome, and No Disease." Journal of Rheumatology 19 (1992): 944.

Source: Medical Disability Advisor






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