Occupational Injury Overview

Occupational injuries generally result from repetitious tasks required daily - and the stressing or wearing down over time of muscles, tendons, ligaments and other tissue of the limb required to perform the task. Though less common, occupational injuries can also result from a single harsh impact or blow.

Occupational injuries resulting from overstress of the same movements are treated differently than those resulting from a single incident. Work-related overstress injuries require treatment that enables the continuation of the same task. They also require special rehabilitation, in order to not only help patients recover from the injury for which they are treated but also understand how their limb can be positioned differently to reduce the stress that their activity poses to it.

Dr. Hildreth works closely with the Physiotherapy specialist at Methodist to ensure that a patient's quality of life is not negatively impacted by their occupation.

Carpal Tunnel Syndrome

Carpal Tunnel Syndrome (CTS) is a repetitive strain condition - most often resulting from a constant, repetitive motion associated with a job or activity. The repetitious movement subsequently causes the median nerve, which is located in a narrow passage inside the wrist called the carpal tunnel, to become irritated and compressed with increasing pressure within the tunnel.

Within the carpal tunnel, nine tendons accompany the median nerve - and a covering consisting of a tight ligament called the transverse ligament helps protect it. In patients performing repetitive activity, the membranes that lubricate the tendons as they glide in the tunnel begin to swell. When the median nerve, which provides feeling to the thumb, index and middle fingers, as well as a portion of the ring finger and several muscles in the hand, malfunctions as a result of increasing irritation and swelling, the condition is diagnosed as CTS.

Symptoms may vary and include simply a mild numbness and tingling on the palmar surface of a finger, or a more severe pain that radiates upward towards the shoulder. If untreated, symptoms generally become worse - affecting wrist, hand, or finger movement, as well as reducing grip strength and disrupting sleep.

While most often diagnosed between the ages of 40 and 60, women are diagnosed three times more often than men - generally as a result of hormone-related conditions such as pregnancy, breastfeeding, menopause, hypothyroidism, and excessive growth hormone, all of which create an increased vulnerability and susceptibility to the condition

Others at risk for CTS include those with occupations that entail repetitive hand tasks such as keyboard operators, assembly line workers, typists, barbers, musicians, and drivers. Also at risk are workers using vibrating tools such as jackhammers, chain saws, chippers, grinders, drills and sanders.

Some medical conditions may also increase the likelihood of an individual to suffer CTS - including arthritis, diabetes, Raynaud's disease and tumors and cysts within the carpal tunnel. Genetics may also play a role, as inheriting a narrow carpal tunnel can increase a person's chance of developing the condition.

Imaging tests are also used in the diagnosis of CTS. These tests may involve an X-ray, a computed tomography (CT) scan, or a magnetic resonance imaging (MRI) scan, in order to more precisely identify the root cause of a patients CTS - as well as any other problems that may exist as a result of the condition.

Diagnosis and Treatment
There are a series of tests that help in the diagnoses of CTS. Among the simplest is a Tinel's Sign test, which entails a few firm taps on the patient's wrist in order to assess the patient's response and level of pain. A patient suffering from CTS may feel an electric shock sensation during the taps. A compression test is another fairly simple test effective in the diagnosis of CTS. During this test, the patient's wrist is bent with the thumb positioned down, as close to the forearm as possible. This position is held for a brief moment and the amount of tingling or numbness the patient experiences in the hand is assessed.

Following diagnosis, treatment options are discussed and based on the severity of the condition and the lifestyle and overall health of the patient.

CTS is most often treated with non-invasive methods if diagnosed early. These methods include a period of rest from the repetitive activity, and the use of anti-inflammatory medication to ease pain and reduce inflammation. In more severe cases, a minimally invasive surgical procedure - either an Arthroscopy or an Endoscopic Carpal Tunnel Release - is performed to both diagnose the severity of the condition and treat it.

Rehabilitation
Rehabilitation is one of the most important aspects of treatment for any injury. After a period of rest, patients are encouraged to begin a series of stretching exercises to improve range of motion and grip strength. Depending on the treatment and severity of the condition, the resumption of daily activities and work may range from several days to several weeks. Though, the chance of a recurrence is minimal and complications extremely rare. Rehabilitation Exercises for Carpal Tunnel.

deQuervain's Tendonitis

Generally prompted by awkward hand positions or posture, de Quervain's tendonitis is a condition that results from irritation or swelling of the tendons along the thumb side of the wrist. As the lining around the tendon swells it becomes increasingly difficult for the tendons to move as they should, causing pain and tenderness on the thumb side of the wrist when forming a fist, grasping or gripping.

Swelling is noticeable and may be accompanied by a cyst filled with fluid. Patients may also experience "snapping" when the thumb is moved and have difficulty pinching. If the nerve lying on top of the tendon sheath becomes irritated, patients may also experience numbness on the back of the thumb and index finger.

Risk Factors
de Quervain's tendonitis is commonly found in those required to use their hands in new and awkward positions for a period of time - such as a piano student, or a new mother feeding an infant a bottle or pushing a stroller.

Diagnosis and Treatment
In determining diagnosis, the patient is asked to make a fist with the fingers over the thumb. The wrist is then bent towards the little finger, while the level of discomfort and range of motion is assessed. Patients also report tenderness directly over the tendons on the thumb side of the wrist.

Patients suffering from de Quervain's tendonitis are asked to refrain from the activity that prompted the swelling. Anti-inflammatory medication may also be used to reduce swelling and relieve pain. When the condition is nonresponsive to conservative treatment, a surgical procedure called de Quervain's Release is performed to open the compartment, or sheath, and widen the constricted area for the irritated tendons.

Focal Dystonia Syndrome

Rehabilitation and strengthening exercises are established following surgery.

Focal Dystonia is a musculotendinous overuse or repetitive use condition which is called "simple" if resultant of a single task, such as playing the piano or writing, and "dystonic" if it affects other activities requiring similar hand posture. The condition is believed to result from the improper functioning of the basal ganglia, which are deep brain structures involved in controlling movement. Sometimes the disorder progresses to include the elevation of shoulders or retraction of the arm while writing.

Also commonly referred to as "writer's cramp" or graphospasm, the exact cause of this improper functioning is unknown though thought to be the result of muscular overuse in posture-specific activities involving the hand. Symptoms include cramping or a slight aching in the fingers, wrist or forearm. Symptoms usually occur when performing the task that requires fine motor movements -initially only during specific tasks and eventually spreading to other tasks requiring similar hand positioning.

Unlike other over-use conditions prompting muscle cramps and pain, such as Carpal Tunnel Syndrome - a condition for which it is often mistaken, Focal Dystonia Syndrome is more likely to affect coordination and cause only mild discomfort.

Risk Factors
The condition affects both men and women between the ages of 30 and 50, who are involved in specific activities requiring the repetitive use of unique hand posture - such as musicians (pianists, violinists) writers, typists, and some athletes involved in such sports as golf.

Diagnosis and Treatment
A thorough physical examination, detailed patient history review and possibly a neurological examination will confirm Focal Dystonia Syndrome. An electromyogram (EMG) can also help determine which muscles are overactive and the degree of stress imposed.

Treatment options generally focus on alleviating the symptoms and consist of a period of rest and refrain from the activity that prompted the condition. In chronic cases, either oral medication, or botulinum toxin injections may be indicated. More severe cases may require surgery. Physical therapy and muscular retraining may also be beneficial, depending on the form and degree of severity of the condition.

Guyon's Canal Syndrome

Similar to the type of compression placed on the median nerve in Carpal Tunnel Syndrome cases, Guyon's Canal Syndrome is a less common nerve compression affecting the ulnar nerve as it passes through a tunnel in the wrist called Guyon's Canal.

Running from the neck and down the arm to the hand and fingers, the ulnar nerve crosses the wrist with the median and radial nerves. The ulnar nerve and ulnar artery run through the Guyon's canal - a tunnel formed by two bones, the pisiform and hamate and connecting ligaments. Once it passes through the canal, it branches out to supply feeling to the little finger and half of the ring finger. Other branches of this nerve supply the small muscles in the palm, as well as the muscle that pulls the thumb toward the palm. A number of activities or other conditions may cause the ulnar nerve to become compressed, resulting in this condition.

Symptoms generally include numbness in the little finger and half of the ring finger. Progression can cause the gradual weakening of the muscles controlled by the ulnar nerve, which eventually makes it difficult to spread out the fingers and pinch the thumb.

Risk Factors
Generally adult men and women involved in strenuous tasks involving the wrist, such as; heavy gripping or twisting, constant pressure placed on the palm such as in cycling and weightlifting, and uncommon or unnatural activities placing great pressure on the wrist such as using a jackhammer or crutches, or pushing a stroller, are at greatest risk for Guyon's Canal Syndrome.

A traumatic injury to the wrist may also cause swelling and place pressure on the ulnar nerve within the canal. And arthritis in the wrist bones and joint may irritate and compress the nerve as well.

Diagnosis and Treatment
Upon a thorough physical examination, patient history review and possible nerve conduction velocity (NCV) test, which measures how fast nerve impulses travel along the nerve, the type of compression and its exact location are determined.

Occasionally the NCV test is performed in conjunction with an electromyogram (EMG). The EMG can determine if the forearm muscles controlled by the ulnar nerve are functioning properly. If the symptoms were the result of a traumatic wrist injury, an X-ray may be taken to check for a fracture or dislocation.

Conservative treatment is generally all that is indicated for Guyon's Canal Syndrome - NSAIDs and reduction of the activity causing the pressure, or change of hand position. Physical therapy may help to facilitate this process. A wrist brace may also be used to alleviate the symptoms by keeping the wrist in "resting position" and decreasing the pressure placed on the nerve.

A surgical procedure to release the ligament above the canal and reduce the pressure to the ulnar nerve is performed, if conservative treatment is unsuccessful.

Hypothenar Hammer Syndrome (HHS)

Hypothenar Hammer Syndrome (HHS) is a neurovascular overuse condition that generally results from a continuous, or ongoing pounding motion affecting the ulnar side of the palm, the hypothenar region. It is often prompted by a trauma to the ulnar artery distal to the Guyon's canal, leading to thrombosis of the ulnar artery.

Symptoms of HHS may include sensitivity to cold and pain in the palm, as well as ulnar digital numbness and tingling. More severe cases may result in weakening grip strength, discoloration of the finger and an ulcer at the fingertip.

Risk Factors
HHS often affects those involved in such sports-related activities as excessive biking, karate, and lacrosse. It also affects those involved in non sports-related activities such as the use of a jackhammer or repeated hammering required in roofing. In fact, those involved in manual labor that subjects hands to constant pounding and aggressive motion are most frequently diagnosed with the condition.

Diagnosis and Treatment
The patient's medical and work history, as well as the symptoms experienced and location of the pain, will often times identify this condition. Imaging scans may also be indicated in order to identify any obstruction to the blood vessel that may exist.

While surgery is required in some severe cases of HHS, conservative treatment is generally all that is indicated - refraining from the activity prompting the condition, rehabilitative exercises and possibly medication to assist in blood flow.

Trigger Finger

Also known as Tenosynovitis, Trigger Finger or thumb is named for the "trigger" or flicking motion that is caused when the affected finger is extended. This happens when a stress placed on the tendons that help bend the fingers and thumb causes irritation and corresponding restriction in the already snug tunnel through which they slide. While flexion remains relatively unaffected, extending the finger or thumb in this environment causes the tendon to become momentarily stuck at the mouth of the tunnel before popping free as it continues to slip through the constricted area. This may cause pain.

Following a period of inactivity, stiffness and "catching" may become worse. As it loosens throughout the day, it may begin to feel unstable. And in severe cases, the finger may become stuck in a bent position.

Risk Factors
While the exact cause of Trigger Finger is unclear, the condition most often affects women between the ages of 40 and 60. It is thought that this condition is often secondary to an existing medical condition, as many of the patients suffering from trigger finger also suffer from other conditions such as diabetes and rheumatoid arthritis, or have a history of repeated injury to the affected area.

Diagnosis and Treatment
Easily diagnosed, the symptoms generally point to trigger finger or thumb. And a thorough patient history review and physical examination of the affected area confirms the diagnosis without further tests.

Conservative treatment is all that is indicated in mild cases, which generally entails resting the affected hand. Anti-inflammatory medication may also be recommended in order to alleviate pain. More severe cases failing to respond to initial conservative treatment may require splinting to maintain the finger or thumb in a position of rest. Cortisone treatments may also be used. In those cases nonresponsive to the described courses of conservative treatment, Trigger Release may be indicated.