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.

Carpal Tunnel Syndrome


Related Terms

  • Compression Neuropathy
  • CTS
  • Median Nerve Compression
  • Median Nerve Entrapment Wrist
  • Median Nerve Mononeuropathy

Differential Diagnosis

Specialists

  • Ergonomist
  • Hand Surgeon
  • Neurologist
  • Neurosurgeon
  • Occupational Therapist
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist

Comorbid Conditions

  • Diabetes mellitus
  • Obesity
  • Rheumatoid arthritis
  • Thyroid illness
  • Toxic exposures

Factors Influencing Duration

Tolerance is the limiting factor for disability durations. The ability (or lack thereof) to limit activities that increase the symptoms, the response to conservative treatment, and the ability to perform tasks while wearing adaptive splints may influence disability time. Surgical technique such as mini-palm and endoscopic allow for earlier return to work that the traditional CTS surgery.

Medical Codes

ICD-9-CM:
354.0 - Carpal Tunnel Syndrome; Median Nerve Entrapment; Partial Thenar Atrophy

Overview

© Reed Group
Carpal tunnel syndrome (CTS) is a condition that results in symptoms of numbness, paresthesia, or pain in the distribution of the median nerve at the wrist. The exact pathophysiology is not completely understood but can be viewed as compression of the median nerve as it passes from the forearm into the hand at the level of carpal ligament. The median nerve is the main nerve of the hand. Its branches enter the hand through a narrow passageway (carpal tunnel) formed by the wrist bones (carpal bones) and the tough ligament that holds the tendons in place (the transverse carpal ligament). The median nerve supplies sensation to the thumb, index finger, middle finger, and, in most people, to part of the ring finger. Because this passageway is rigid, thickening of structures, inflammation, swelling, or increased fluid retention may compress the nerve (nerve entrapment), causing pain and numbness in the fingers (particularly the thumb and the index and middle fingers) and, over time, hand weakness. Pain may eventually extend to the arm, shoulder, and, rarely, the neck. Sensation in the palm is not always affected because of a branch of the median nerve that does not go through the carpal tunnel.

Any condition, trauma, or injury that increases pressure on the median nerve and tendons in the carpal tunnel can result in carpal tunnel syndrome, including a smaller carpal tunnel than normal, wrist injury such as sprains or fractures that produce swelling and alter the shape and size of the carpal tunnel, overactive pituitary gland, underactive thyroid, synovitis of rheumatoid arthritis, repeat use of vibrating hand tools, fluid retention during pregnancy or menopause, or the presence of a cyst or tumor.

Incidence and Prevalence: An estimated 5% of the US population is affected by carpal tunnel syndrome (Hooker). Idiopathic CTS is more common in adults (NINDS). During the period from 1981 to 2005, the average annual incidence of carpal tunnel release surgery was 109 per 100,000, while that for work-related CTS was 11 per 100,000 (Gelfman).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Specific risk factors for carpal tunnel syndrome remain controversial; there are few clinical data to show that repetitive or forceful hand and wrist movement can result in carpal tunnel syndrome (Garg).

Currently, no single ergonomic risk factor is sufficient to establish a causal relationship. Occupational risk factors include force and repetition, force and posture (strong evidence); vibration (some evidence); highly repetitive work (some evidence); forceful work (some evidence); carpal tunnel size (some evidence); awkward postures (insufficient evidence); keyboards (insufficient evidence); cold environment (insufficient evidence); length of employment (insufficient evidence); and dominant hand (insufficient evidence). Non-occupational risk factors include age (very strong evidence); increasing BMI (very strong evidence); gender (strong evidence – female); biopsychosocial (strong evidence); diabetes (strong evidence); and smoking (insufficient evidence) (Melhorn, "Disease and Injury Causation," 171).

Underlying or comorbid conditions that can increase the risk of developing CTS include rheumatoid arthritis, renal failure, diabetes mellitus, acromegaly, multiple myeloma, amyloidosis, obesity, recent tuberculosis, and bacterial or fungal infection that spreads into the carpal tunnel.

Carpal tunnel syndrome is more common in those who develop trigger digit, elbow tendinopathy (epicondylitis), and ulnar nerve mononeuropathy at the elbow. Those associations raise the question of a congenital predisposition to musculoskeletal disorders (Garg).

Trauma or injury, such as a wrist fracture that decreases the size of the carpal tunnel or wrist sprain that causes swelling of the synovial tissue covering the tendons in the carpal tunnel (tenosynovitis), may increase the risk of CTS. It may also occur in some individuals with degenerative neck conditions (cervical spondylosis). An increased frequency of CTS has been shown in alcoholics. Smokers may experience worse symptoms and a longer recovery time from CTS than non-smokers.

Women are 3 times more likely to develop the syndrome than men because of their typically smaller carpal tunnel. Risk increases with advancing age. For women, the peak time for developing CTS is between ages 45 and 54. Women who are pregnant, taking oral contraceptives, or going through menopause are also more prone to develop the condition due to fluid retention ("Carpal Tunnel Syndrome").

Source: Medical Disability Advisor



Diagnosis

History: Individuals may describe pain, tingling, numbness, or a feeling of weakness in the fingers, hand or wrist. In mild cases, the symptoms are intermittent and often worsen at night or when the individual first arises in the morning. The individual may complain of decreased grip strength, dropping items more frequently than usual, and having problems pinching or grasping items or making a fist. The fingers may at times feel "locked," and the individual may feel a need to shake the hand and fingers to unlock them. On occasion, pain may radiate into the forearm, shoulder, neck, or chest. The hands or lower arms may feel weak in the morning after sleeping with wrists flexed. Performance of detailed tasks such as writing or tying shoes may be difficult. Symptoms may occur during specific activities or at particular times, such as while holding a phone or a newspaper, gripping a steering wheel, or sleeping. The individual may experience decreased ability to determine hot or cold by touch.

Physical exam: The physical exam may reveal no abnormalities. Subjectively altered sensation may be noted in the distribution of the median nerve in the thumb and the first three fingers, with no changes in sensation in the palm. Even though patients frequently complain of "swelling," soft tissue swelling is not usually observed in CTS. In chronic or severe cases, the palm may appear to be wasting away near the thumb (thenar eminence atrophy). In severe cases, weakness of thumb opposition and decreased sensation in the distal phalanges of the thumb and first three fingers (2 point discrimination and / or monofilament testing) may be noted. The individual may be shown a diagram of the hand and wrist to indicate where pain or other sensations are present. An unaffected little finger may indicate CTS.

Tapping on the palm side (volar aspect) of the wrist over the course of the median nerve near the front of the wrist typically reproduces the tingling feeling in the hand or forearm (commonly described as Tinel's sign). Positioning the wrist in a fully flexed posture for 60 seconds may reproduce the pain, numbness, or tingling (Phalen's sign). These methods have a high rate of both false positive and false negative findings (Chan). Hand grip strength test may show weakness.

Tests: Electrodiagnostic nerve tests are performed to evaluate nerve function (e.g., nerve conduction velocity, electromyography). Nerve conduction tests apply small electric shocks and measure the speed (velocity) with which nerves are able to transmit impulses. Mild cases may show prolonged sensory and / or motor distal latency of the median nerve and slowing of the conduction velocity in the carpal tunnel. Moderate cases show conduction block, in which some of the axons or nerve fibers fail to transmit impulses, resulting in decreased amplitude (voltage) on nerve conduction. Severe cases, which are uncommon, show significant prolongation of motor latency and reduced conduction speed, evidence of axon loss or death of some of the axons in the nerve. There is no agreement about the definitions of mild, moderate, or severe CTS with regard to electrodiagnostic testing, but abnormal results on nerve conduction tests confirm CTS.

Electromyography involves insertion of a fine needle into a muscle and recording of the electric impulses so that electrical activity seen on a monitor can reveal damage to the nerve supplying the muscle tested. The most severe cases will show voltage or at least conduction block, suggesting more severe nerve injury.

Blood tests (serology) to detect possible underlying rheumatoid arthritis (sedimentation rate), diabetes, and thyroid disease are frequently performed. Plain film x-rays of the wrist are used to rule out bony abnormalities, but are almost always normal. MRI and ultrasound are currently considered to be experimental methods of evaluating for the presence of CTS. If a tumor in the carpal tunnel is a rare but possible explanation for an individual's carpal tunnel syndrome, MRI may be used.

Source: Medical Disability Advisor



Treatment

Conservative treatment should include education of the patient about the condition and may also include modifying tasks that seem to exacerbate the symptoms, such as repetitive motion of the wrist and fingers or wrist-bending extremes (flexion and extension). Other treatment may include use of nonsteroidal anti-inflammatory drugs (NSAIDs such as aspirin or ibuprofen), wearing protective splints while working and / or sleeping, stretching and strengthening exercises, diuretics to reduce excess fluids, and possible corticosteroid injections into the carpal tunnel. An electrical current may be used to deliver medication (usually corticosteroids) through the skin into the area requiring treatment (iontophoresis). Studies have shown that vitamin B6 (pyridoxine) supplements help reduce symptoms of CTS only in those who are deficient in this vitamin; yoga has been shown to reduce pain and increase grip strength (NINDS).

In chronic or severe cases unrelated to fluid buildup in pregnancy or menopause, surgery is appropriate. The procedure (open carpal tunnel release) involves cutting the transverse carpal ligament (roof of the carpal tunnel) to relieve pressure on the median nerve. This is generally done on an outpatient basis with local or regional anesthesia. In some cases, surgery can be performed endoscopically by inserting a fiberoptic endoscope through a small incision to observe the inside of the carpal tunnel while incising the transverse carpal ligament (endoscopic carpal tunnel release).

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.*
 
Carpal Tunnel Syndrome
 
* 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

Recurrence of CTS after nonsurgical treatment is difficult to determine. If pain and tingling increase or weakness persists despite nonoperative treatment, surgery may be necessary. Recurrence of CTS after successful surgical treatment is rare. Most patients enjoy near complete recovery if the surgery is provided early before significant permanent damage to the nerve has occurred. If the carpal tunnel release surgery occurs late, some residual numbness, pain, weakness, or stiffness may persist.

Source: Medical Disability Advisor



Rehabilitation

Conservative management can be effective in some cases of carpal tunnel syndrome. After a diagnosis of CTS, reduction of the symptoms and the identification of activities that increase the symptoms, both at home and at work, are the first goals. Therapists must devise specific plans that will help the individual maintain a neutral wrist posture and reduce activities such as forceful pinching or gripping that may increase the symptoms during the course of daily activities. In the workplace, modified work is important until symptoms resolve. This needs to be specifically addressed with company representatives, if possible. When available, alternative work options may be helpful. An ergonomic evaluation of the workplace is usually necessary when the workplace is thought to be the causative factor (Hegmann).

Steroid injections and nocturnal splinting are most commonly used (Piazzini). However, manipulation, nerve and tendon gliding exercises, low-level laser, electrical stimulation, and other passive modalities are not thought to be effective (Work Group Members). Pulsed ultrasound, cold modalities, lidocaine patches and oral steroids for those who refuse steroid injections may also be used (Work Group Members; Hegmann). Heat is contraindicated (Work Group Members).

For post surgical treatment see Carpal Tunnel Release.

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistCarpal Tunnel Syndrome
Occupational / Hand / Physical TherapistUp to 3 visits within 8 weeks
Surgical
SpecialistCarpal Tunnel Syndrome
Occupational / Hand / Physical TherapistUp to 5 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. The number of visits have been adjusted (2009), bringing them into harmony with "Carpal Tunnel Release" and with current best practices.

Source: Medical Disability Advisor



Complications

In half of the cases in which CTS occurs in one wrist, the other wrist eventually become involved. Pain, numbness, and weakness may become constant in advanced cases and may eventually involve the entire arm to the shoulder. If surgery has been performed, there is a chance that some numbness, pain, stiffness, or weakness may persist.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

The ability to work is determined by the severity of the symptoms and the treatment provided. In the early phase, the individual may need to decrease tasks requiring repetitive wrist motion and extremes of wrist bending (flexion, extension) until the condition improves. Additionally, protective wrist splints may be used at sleep to maintain neutral wrist positions. Accommodation may be required at workstations, such as ergonomically designed computer keyboards to provide support for the individual's hand and wrist. If the individual has had surgery and the operated hand must be used for heavy activity, time off from work may be needed for several weeks for recovery. After surgery, the individual may be required to avoid heavy lifting and highly repetitive motion for up to 1 month after surgery. Grip strength may continue to improve for 1-2 years after surgery.

Risk: The risk for recurrent CTS is low (Szabo).

Capacity: Most activities can be safely performed in the pre and post-operative period. Limiting forceful grip along with tolerance is the key during the early phases. Traditional wound healing requires avoiding contact with chemicals and limit extended periods of soaking with water to the surgical incision site. Return to heavy activities gradually, much like a long distance runner in training, is appropriate (Talmage; Melhorn).

Tolerance: Tolerance for symptoms is dependent on rewards. Self employed individuals often return to regular activities as tolerated while employed individuals may have various lengths of disability. Outcomes for workers' compensation patients are poorer than for those without workers' compensation (Adams).

Accommodations: The key to limited unnecessary disability is communication. It should focus on what the patient can do, instead of on what the patient cannot do (because the latter may be enabling in the psychological sense). Communication with the employer should focus on the benefits for the patient (their employee) of stay at work or early return to work. For further information, please refer to "Work Ability and Return to Work," pages 1-8.

Source: Medical Disability Advisor



Maximum Medical Improvement

60 to 90 days post surgery.

Continued improvement is possible over 540 days (18 months), but the amount of improvement is limited.

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:

  • Does individual have pain, tingling, numbness, or feeling of weakness in the wrist, hand, or fingers? Is pain intermittent, often worsening at night or when individual first gets up in the morning?
  • Does individual complain of dropping items more frequently than usual?
  • Do fingers feel "locked" at times? Is associated but untreated trigger digit present?
  • Does individual have problems pinching or grasping objects?
  • Does physical exam reveal changes in sensation along the median nerve in the thumb and first three fingers?
  • Does palm appear to be wasting away near the thumb (thenar eminence atrophy) indicating potentially severe neuropathy, or comorbid osteoarthritis of the thumb carpal-metacarpal joint?
  • Does individual have Tinel's or Phalen's sign?
  • Does the individual have comorbid lateral elbow tendinopathy or ulnar neuropathy at the elbow?
  • Does the individual have comorbid shoulder or neck pathology?
  • Were nerve conduction studies performed to evaluate the nerve function (distal latency, nerve conduction velocity, electromyography needle testing), and if so, were the results normal or abnormal?
  • Was testing for inflammatory disease (sedimentation rate) and thyroid disease (TSH) that might cause or masquerade as CTS performed?

Regarding treatment:

  • If conservative methods have failed to relieve symptoms, is individual a candidate for carpal tunnel release?
  • If the case is atypical, did an injection of steroids reduce numbness and pain prior to an attempt at surgery?
  • Did individual undergo open or endoscopic carpal tunnel release?
  • Did individual experience any complications from the surgical procedure itself?
  • Did the operation report describe inflammatory synovium suggesting inflammatory disease and not idiopathic CTS was present? If "yes", was a synovial biopsy done? If the biopsy showed inflammatory cells in the synovium, has the patient been referred to a rheumatologist?
  • Does individual continue to experience symptoms even after surgical intervention? If yes, were repeat nerve conduction tests done by the same physician to see if the nerve function improved?
  • What further treatment options are being considered?

Regarding prognosis:

  • Does pain persist even after 2 months have passed since treatment?
  • Does individual perform repetitive tasks such as gripping a tool for prolonged periods of time?
  • Can individual refrain from activities that may increase the symptoms for as long as pain or other symptoms persist?
  • Until symptoms resolve, should individual be transferred temporarily to a position that does not require repetitive motion?
  • Is individual's work station or computer keyboard ergonomically designed to provide support for the hand and wrist?
  • Was individual given a splint to provide support for the wrist and hand? If so, is it being used as instructed?
  • Does individual have a coexisting condition such as diabetes or pregnancy that may affect recovery?

Source: Medical Disability Advisor



References

Cited

"Carpal Tunnel Syndrome Fact Sheet." National Institute of Neurological Disorders and Stroke. 7 2012. National Institutes of Health (NIH). 18 Apr. 2013 <http://www.ninds.nih.gov/disorders/carpal_tunnel/detail_carpal_tunnel.htm>.

"Carpal Tunnel Syndrome." MayoClinic.com. 22 Feb. 2011. Mayo Foundation for Medical Education and Research. 18 Apr. 2013 <http://www.mayoclinic.com/health/carpal-tunnel-syndrome/DS00326/DSECTION=risk-factors>.

Adams, M. L. , et al. "Outcome of carpal tunnel surgery in Washington state workers' compensation." American Journal of Industrial Medicine 25 (1994): 527-536.

Chan, J. A. , et al. "The relationship between electrodiagnostic findings and patient symptoms and function in carpal tunnel syndrome." Archives of Physical and Medical Rehabilitation 88 (1) (2007): 19-24.

Garg, A. , et al. "The WISTAH hand study: A prospective cohort study of distal upper extremity musculoskeletal disorders." BMC Musculoskeletal Disorders 13 (1) (2012): 90.

Hegmann, Kurt T., et al., eds. "Chapter 11: Hand, Wrist and Forearm Disorders." Occupational Medicine Practice Guidelines: Evaluation and Management of Common Health Problems and Functional Recovery in Workers. 2008 Revision 2nd ed. ACOEM, 2008. 627-652.

Hooker, Edmund. "Carpal Tunnel Syndrome." eMedicine Health. Eds. Scott Plantz, et al. 31 Jan. 2007. WebMD, LLC. 18 Apr. 2013 <http://www.emedicinehealth.com/articles/5013-1.asp>.

Melhorn, J. M. Impairment without Disability. Ed. W. G. Buchta. Mayo Clinic, 2011.

Melhorn, J. Mark, and William Ackerman, eds. Disease and Injury Causation, Guides to the Evaluation of. AMA Press, 2008.

Piazzini, D. B. , et al. "A Systematic Review of Conservative Treatment of Carpal Tunnel Syndrome." Clinical Rehabilitation 21 4 (2007): 299-314. PubMed. 6 Oct. 2010 <PMID: 17613571>.

R, Gelfman, et al. "Long-term trends in carpal tunnel syndrome." Neurology 72 (1) (2009): 33-41.

Szabo, R. M. , and M. Madison. "Carpal tunnel syndrome as a work-related disorder." Repetitive motion disorders of the upper extremity. Academy of Orthopedic Surgeons, 1995. 421-434.

Talmage, J. B. , J. M. Melhorn, and M. H. Hyman, eds. Work Ability and Return to Work, AMA Guides to the Evaluation of. Second ed. Chicago: AMA Press, 2011.

Work Group Members. "CTS Treatment Guideline." AAOS. American Academy of Orthopaedic Surgeons. 18 Apr. 2013 <http://www.aaos.org/Research/guidelines/CTStreatmentguide.asp>.

Source: Medical Disability Advisor






Feedback
Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment. If you are seeking medical advice, please contact your physician. Thank you!
Send this comment to:
Sales Customer Support Content Development
 
This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is published with the understanding that the author, editors, and publisher are not engaged in rendering medical, legal, accounting or other professional service. If medical, legal, or other expert assistance is required, the service of a competent professional should be sought. We are unable to respond to requests for advice. Any Sales inquiries should include an email address or other means of communication.