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.

Tarsal Tunnel Syndrome


Related Terms

  • Neuropathy of Distal Tibial Nerve
  • Tibial Neuropathy at the Ankle

Differential Diagnosis

  • Amyloid neuropathy
  • Charcot disease
  • Ganglion cyst
  • Hereditary motor and sensory neuropathies
  • Lumbar disc disease
  • Peripheral neuropathy (paralysis)
  • Plantar fasciitis
  • Posterior tibialis dysfunction
  • Reactive arthritis (previously called Reiter's syndrome)
  • Rheumatoid arthritis
  • Stress fractures

Specialists

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

Comorbid Conditions

Factors Influencing Duration

Factors influencing the length of disability include the individual's general health and fitness, mental and emotional stability, access to rehabilitation facilities, compliance with recommended treatment, and response to medical or surgical treatment. Individuals whose jobs require them to use their foot in repetitive pedaling movements or to be on their feet for long periods of time and who cannot be retrained for other positions may be permanently disabled.

Medical Codes

ICD-9-CM:
355.5 - Tarsal Tunnel Syndrome

Overview

© Reed Group
Tarsal tunnel syndrome is a compression neuropathy in the foot with symptoms of pain and abnormal sensations such as numbness and tingling (paresthesias). The posterior tibial nerve runs through a narrow tunnel (tarsal tunnel) behind the bony protuberance on the inner side of the ankle and into the foot. The tunnel itself is formed by a dense band of fibrous tissue that supports and strengthens the ankle joint (the flexor retinaculum). Anything that takes up space in or compresses the tarsal tunnel will put pressure on the nerve and cause inflammation and pain. This condition is similar to carpal tunnel syndrome, which occurs in the wrist.

Causes of tarsal tunnel syndrome include abnormal growth of tissue near the tunnel (tumors, cysts, lipomas, nerve ganglions, scar tissue following trauma), active swelling or bleeding into the tunnel following trauma to the foot or ankle, or the inflammation and swelling of neighboring tendons as a result of rheumatoid arthritis. Individuals with exceptionally flat feet (pes planus) are susceptible to tarsal tunnel syndrome because the flattening (pronation) of the arch causes muscles in the area to compress the nerve.

Incidence and Prevalence: The prevalence and incidence of tarsal tunnel syndrome are unknown (Persich).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Tarsal tunnel syndrome is the most common entrapment neuropathy in the foot and ankle area. It is slightly more common in women than men and occurs across a wide spectrum of ages (14–80 years) (Hollis). Other than a possible association of tarsal tunnel syndrome with repetitive motions of the foot during the operation of foot pedals (Hollis), there is no known correlation with work conditions or activities of daily living (Persich). Obesity is a risk factor for this syndrome because excessive weight can weaken the structure of the foot, resulting in compression of the posterior tibial nerve. Diabetes, alcoholism, thyroid disease, and vitamin deficiencies all place individuals at increased risk of entrapment neuropathies, including tarsal tunnel syndrome.

Source: Medical Disability Advisor



Diagnosis

History: It is important to obtain a complete medical history, including other medical conditions, especially those that may predispose to neuropathy (diabetes, hypothyroidism, pregnancy, alcoholism, malnutrition); past orthopedic and surgical history of the feet and legs; current medications, including vitamin use; family history; foreign travel; possible exposure to HIV; and occupational and recreational history, particularly exposure to solvents or heavy metals. Individuals with tarsal tunnel syndrome experience persistent pain on the sole of the foot that is described as burning and / or tingling (pins and needles). The pain may radiate to the tips of the toes and up the lower leg. Typically, this pain is relieved by rest and elevation or by massage. The pain usually worsens as the day progresses (in contrast to the heel pain caused by plantar fasciitis, which is worse in the morning). Symptoms of tarsal tunnel syndrome usually occur in one foot (unilateral) rather than both feet (bilateral). Some individuals may experience what they perceive as impaired balance due to numbness or pain on the sole of the foot. Consequently, they may report limited tolerance for walking, along with stumbles or falls.

Physical exam: Exam of the individual with tarsal tunnel syndrome may reveal few objective signs of nerve compression. Signs of numbness (paresthesia) and muscle weakness may be present. Tapping (percussion) of the area above the tarsal tunnel may cause the individual to feel an uncomfortable tingling sensation that radiates toward the toes (Tinel's sign). Symptoms may also be aggravated at the extremes of range of motion when turning the sole of the foot outward (eversion) and pointing the toes upward (dorsiflexion). There may be atrophy of the intrinsic muscles of the foot.

Tests: Diagnosis of tarsal tunnel syndrome typically is based on the individual’s history and results of physical examination (clinical diagnosis). In cases in which clinical findings remain nondiagnostic, plain x-rays and CT scans are useful for detecting skeletal abnormalities, including growths (exostoses and osteochondromas) that may project from a bone and cause nerve compression. Hidden (occult) sources of pain, such as undiagnosed fractures, may also be discovered on x-rays. MRI and ultrasound can help rule out tendon inflammation and lesions. In cases in which diagnostic images appear normal, or to confirm a suspected case of tarsal tunnel syndrome, electromyography (EMG) may be performed to study nerve function. A nerve conduction velocity (NCV) test can measure how fast the nerve impulses travel along the posterior tibial nerve. If the impulses travel slowly across the ankle, it may confirm a diagnosis of tarsal tunnel syndrome. The absence of these findings, however, does not preclude individuals from subsequently undergoing and benefiting from a surgical release of the tibial nerve to relieve symptoms (Persich).

The following screening blood work can help to rule out other causes of symptoms: fasting serum glucose level, erythrocyte sedimentation rate (ESR), hemoglobin A1c, vitamin B12 level, blood urea nitrogen (BUN), creatinine (Cr), and complete blood count (CBC).

Source: Medical Disability Advisor



Treatment

Initial medical treatment of tarsal tunnel syndrome should address any underlying causes, such as trauma, arthritis, and tumors. Periods of rest, application of ice, use of nonsteroidal anti-inflammatory (NSAID) medications, and immobilization with a walking foot cast may be appropriate. Injection of the tarsal tunnel with a corticosteroid and local anesthetic may give temporary relief of symptoms. This must be done with great caution since nerve damage can result from improper needle placement. Physical therapy can help to reduce tissue swelling (edema) and stretch the muscles in the calf. Special shoes and over-the-counter arch supports may decrease the amount of foot pronation and help maintain better alignment of the foot and ankle. In individuals with exceptionally flat feet (pes planus), a foot orthosis can redistribute weight and reduce tension on the tibial nerve (Persich). Wearing splints at night to keep the foot in proper alignment may help in some cases. If the underlying cause of the syndrome is obesity, a weight loss program may be prescribed. Surgical removal of abnormal tissue and bone growths may be necessary to relieve pressure on the nerve.

If symptoms persist longer than 6 months or muscle weakness develops, surgical release of the posterior tibial nerve (tarsal tunnel release) may be indicated. In this procedure the laminate ligament is cut, allowing the nerve to expand. Endoscopic tarsal tunnel release may be an option in some cases (Del Toro).

Source: Medical Disability Advisor



Prognosis

The outcome following conservative medical treatment of tarsal tunnel syndrome is generally good. Individuals whose symptoms began less than a year prior to treatment experienced better outcomes than those who had symptoms for a longer time (Hollis). Surgical removal of tumors and other abnormal tissue growths is also associated with good outcomes. However, the surgical outcome following tarsal tunnel release is less satisfactory, with successful outcomes ranging from 44% to 78%, depending on the study (Del Toro). Following tarsal tunnel release and partial plantar fasciotomy, one study indicated 84% of individuals might see improvement in their symptoms (Hollis). If nerves running into the area become bruised or damaged during surgery, however, they may form a painful spot under the scar (neuroma) or cause numbness in the foot. Damaged nerves can require many months to regenerate. As the damaged nerves regenerate, the individual may experience an unpleasant tingling sensation in the foot. Another study showed that roughly 75% of people who had tarsal tunnel release had a decrease in their symptoms, and 25% of individuals who had tarsal tunnel release had minimal pain or no decrease in pain (Persich).

Source: Medical Disability Advisor



Rehabilitation

Rehabilitation for tarsal tunnel syndrome focuses on preventing loss of motion and strengthening the ankle and toes. Gentle stretching exercises of the involved area are indicated, avoiding movements that reproduce symptoms. Careful attention must be paid to strengthening both the extrinsic and intrinsic muscles of the foot (Del Toro). Foot orthotics are recommended (Del Toro) to correct instabilities and alignment problems that may have contributed to the current diagnosis and to relieve tension on the tibial nerve. Common clinical practice includes the use of modalities such as massage, heat, and ice for symptomatic relief (Del Toro).

Most cases are idiopathic although trauma is frequently involved (Shapiro). When the etiology can be identified, the rehabilitation may specifically target the cause. Changes in footwear may be necessary with custom orthoses (Del Toro). If swelling or venostasis caused symptoms, then use of compressive stockings (Lau) in conjunction with range of motion exercises with the foot in a nondependent position may be beneficial. When obesity is the cause, the physical therapist, working closely with the physician, may design a general exercise and conditioning program aimed at weight reduction (Lau). In cases in which trauma or an inflammatory process is suspected, local injections may be indicated after conservative treatment has been proven unsuccessful (Del Toro). Gait and balance training may also be useful (Del Toro).

Individuals should be taught a home exercise program to complement the supervised rehabilitation. These exercises should be continued even after discharge from therapy.

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistTarsal Tunnel Syndrome
Physical TherapistUp to 12 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

Typical complications associated with any surgery include bleeding, infection, and poor wound healing. Laceration of the nerve or posterior artery during surgery may lead to serious problems with foot function. Chronic foot pain is a possible complication. Compression of the posterior tibial nerve may lead to permanent nerve damage if treatment is delayed or unsuccessful. Diminished sensation may lead to skin breakdown, including ulcerations, on the sole of the foot. Perceived feelings of unsteadiness may change an individual’s manner of walking (altered gait), which may lead to lower back or knee and hip pain.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individuals with tarsal tunnel syndrome may need to avoid being on their feet for long periods of time until their symptoms diminish or go away. Individuals who have had surgery will typically avoid weight bearing for 3 weeks, followed by a gradual and progressive return to weight bearing. Individuals operating machines requiring repetitive pedaling may need to be reassigned to another position temporarily, if not permanently. Those who experience permanent nerve damage or chronic pain in their feet and whose jobs require them to be on their feet for long periods of time may need to be reassigned to jobs that permit them to sit.

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 tarsal tunnel syndrome been confirmed?
  • Does the current pain differ in any way from the original pain that caused the individual to seek treatment?
  • Has the foot been examined by x-ray or CT scan to rule out abnormal tissue growth?
  • Has muscle weakness in the foot progressed?
  • Was a nerve conduction velocity (NCV) test performed to measure how fast the nerve impulses travel along the posterior tibial nerve?
  • Does individual have an underlying condition, such as diabetes, peripheral vascular disease, peripheral neuropathy, rheumatoid arthritis, or congenital or post-traumatic foot deformities that may be affecting recovery?

Regarding treatment:

  • Has individual complied with all aspects of treatment?
  • Are corticosteroid injections indicated?
  • Has individual received physical therapy if indicated?
  • Did individual purchase and regularly use special shoes or over-the-counter arch supports?
  • Has individual complied with weight loss goals?
  • Would individual benefit from enrollment in a community weight-loss program?
  • Has surgical treatment of the syndrome been considered?

Regarding prognosis:

  • If symptoms have lasted longer than 6 months, or if muscle weakness has developed, is surgical intervention now warranted?
  • Did individual experience complications resulting from surgical procedure?

Source: Medical Disability Advisor



References

Cited

Del Toro, David. "Chapter 88 - Tibial Neuropathy (Tarsal Tunnel Syndrome)." Essentials of Physical Medicine and Rehabilitation. Eds. Walter R. Frontera, Julie K. Silver, and Thomas Rizzo. 2nd ed. Philadelphia: Saunders, Elsevier, 2008.

Hollis, Minoo Hadjari, and David E. Lemay. "Nerve Entrapment Syndromes of the Lower Extremity." eMedicine. Eds. John S. Early, et al. 17 Mar. 2008. Medscape. 3 Apr. 2009 <http://emedicine.medscape.com/article/1234809-overview>.

Lau, J. T., and T. R. Daniels. "Tarsal Tunnel Syndrome: A Review of the Literature." Foot & Ankle International 20 3 (1999): 201-209. National Center for Biotechnology Information. National Library of Medicine. 27 Sep. 2008 <PMID: 10195301>.

Persich, Gianni, and S. Touliopolous. "Tarsal Tunnel Syndrome." eMedicine. Eds. John S. Early, et al. 6 Sep. 2007. Medscape. 3 Apr. 2009 <http://emedicine.medscape.com/article/1236852-overview>.

Shapiro, Barbara E., and David C. Preston. "Entrapment and Compressive Neuropathies." Medical Clinics of North America 93 2 (2009): 285-315.

Source: Medical Disability Advisor






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