Glossary: Ergonomics and Work–Related Injuries

DISCLAIMER The information provided in these pages should not be considered medical advice nor used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies.

• BURSITIS
  • Bursae translates as 'purse or sac'. The purpose of tendons is to connect bone to muscle. They are tough, fibrous ropes than serve their purpose well. The Bursae are fluid–filled sacs that surround the tendon where it connects to the bone and the muscle. They may also fill crevices where tendon or muscle slides over a bony prominence to protect the structures from damage. Bursitis is an inflammation of the Bursae. The inflammation can be caused by a traumatic injury, chronic overuse, or infection. Rheumatoid arthritis and gout are also sometimes listed as causes, but this may be related to the bony changes that occur with these conditions. Sometimes the cause remains unknown.
  • The most common sites for Bursitis to develop are the shoulder, elbow, knee, and hip but the condition can occur wherever bursae are located.
  
  


• CUMULATIVE TRAUMA DISORDERS (CTDs)
  • CTD is a categorical term used to include all injuries that occur over time because of repeated trauma or exposure to a specific agency, such as repetitive stress, chemical inhalation, specific force applications, etc. One experience is not enough. This term indicates injury on top of injury.
  • Theoretically, everyone experiences micro–injuries and tears during the day. Overnight, the body repairs itself. With CTD, the injury is sufficiently extensive that the body cannot complete repair. The next day there is more injury in the incompletely healed area.
  • Common occupational disorders related to Ergonomics in this class include
    • carpal tunnel syndrome
    • epicondylitis (tennis elbow or golfer's elbow)
    • other tendinitis
    • tenosynovitis
    • low back pain
    • etc


• GANGLION CYST
  • These cysts are a puzzle. They are fluid-filled lumps of excess joint fluid that appear as swelling nodules under the skin. They usually occur spontaneously and may shrink or disappear spontaneously. Repetition and friction may be two causes of cysts, but no one really knows. These cysts often occur at specific locations in the wrist or at the base of the fingers and are considered harmless.
  • The most well known Ganglion Cyst is the Bible Thumper cyst that appears on the back of the wrist. The traditional cure for this is to set the wrist securely on a table, take your bible, and thump the cyst with the book. I have seen this work (done by a physician with an anatomy book). I would not try this myself because diagnosis and treatment must be by a medical doctor. A nodule on the back of the wrist might be something besides a ganglion cyst.


• MUSCULOSKELETAL DISORDERS (MSD)
  • MSDs are an inclusive category. In theory, MSD includes any injury that impacts the muscular or skeletal system. Broadly this includes almost all injuries except abrasions and shallow cuts, lung and specific organ injury. Specifically, the term is applied to injuries that impact the muscle, tendon, ligament, cartilage, nerve and joints. It can include sprains and strains but generally does not include fractures. MSD is a more general term than Cumulative Trauma Disorder or Repetitive Strain Disorder because it does not imply causality.


• OCCUPATIONAL ILLNESS
  • Occupational Illness is defined by OSHA as any abnormal condition or disorder EXCEPT Occupational Injury (defined below) caused by exposure to factors associated with employment.
  • It may include exposure to standard disease such as mumps or hepatitis, but focuses on acute and chronic conditions that may be caused by inhalation, absorption, ingestion or direct contact. The broad categories of occupational illnesses as identified by OSHA and NIH are skin diseases and disorders, dust diseases of the lungs, respiratory conditions due to toxic agents, poisoning, disorders due to physical agents other than toxic materials, and disorders from repeated trauma.


• OCCUPATIONAL INJURY
  • Simply, an Occupational Injury is an injury that occurs in the work area. This can be something as obvious as a fracture, sprain or amputation. It can also be a paper cut. The injury must result from a work–related event or from a SINGLE instantaneous exposure in the work environment.


• REPETITIVE STRAIN INJURY — RSI
  • RSI is the result of repetitive strain. It is often used synonymously with Cumulative Trauma Disorder. Most frequently it is the result of repeated over use of a muscle in a task that requires fast or forceful motion through the same or similar pattern. The injury is generally cumulative in nature. On rare occasions the symptoms seem to appear due to a single traumatic incident.


• SYNDROMES
  
  • Syndromes are conditions which are historically diagnosed through an examination of symptoms. In fact, they are defined by the symptoms. Although there are generally multiple symptoms involved, not all or even most need to be present for a diagnosis. A syndrome is a specific diagnosis — such as Carpal Tunnel Syndrome or Reynaud's Syndrome. Most will not be discussed here, but because of their specific injury process, Tunnel Syndromes are presented separately.


• TENDINITIS
  
  • Related to Bursitis, Tendinitis (or Tendonitis) involves inflammation — in this case, inflammation of the Tendon itself. These fibrous tissues are open to injury and may be inflamed for numerous reasons. The most common is overuse. Tendinitis is more likely to occur if there an obstruction along the tendon pathway that impedes the smooth operation of the tendon as it transfers power and movement from the muscle to the bone. Another contributing factor has been identified as the tendon being located in a 'watershed' zone, an area where the blood supply is sparse and the structure is at its weakest. These conditions are quite painful. Frequently the skin above the irritated tendon will be warm or hot to the touch and may be reddened.
  • The conditions are often named after the most commonly related activity seen as the causal factor.
    • Tennis Elbow
    • Golfer's Elbow
    • Pitcher's Shoulder
    • Swimmer's Shoulder
    • Jumper's Knee
    Tendinitis is often not severe when initially seen by a Doctor, because it is painful and irritating enough that people tend to seek help. Untreated, if it is severe it may lead to Tendonosis or to the rupture of a tendon and require surgical repair. Most cases of tendinitis can be successfully treated with rest and medications to reduce the pain and inflammation.


• TENDONOSIS
  • When Tendinitis becomes a chronic condition, it sometimes changes character sufficiently to deserve another name. Tendinosus is a condition where the tendon shows damage at a cellular level. 'Osis' on the end of the word implies that there is a chronic degeneration without inflammation. It is thought to be caused by microtears in the connective tissue in and around the tendon, leading to an increase in tendon repair cells. This may lead to reduced tensile strength, thus increasing the chance of tendon rupture.


• TUNNEL SYNDROMES
  • Tunnel Syndromes can occur anywhere in the body where tendons and nerves follow the same pathway through narrow bony tunnels. The cause is still under investigation, but is frequently considered to be related to repetitive motions, sharp trauma, or excessive swelling. The most common sites are in the wrist,, the elbow, the ankle and in the shoulder or shoulder girdle. Again, bony enlargements related to arthritis may increase the risk of occurrence as they can impinge on the tunnel size and shape.
  • The symptoms of tunnel syndromes are primarily related to pressure exerted on the nerves as they are squeezed by swelling or other impediments within the narrow tunnel. Controlling the swelling results in decease in symptoms.


• VIBRATION INJURY
  • When the body is subjected to excessive vibration through a tool or piece of equipment, it can result in an injury to the blood vessels and nerves. This most commonly occurs with use of hand tools. Whole body vibration which may result from extended periods of truck driving or heavy equipment operation can also result in injury, but more commonly to the spine or disruption to the internal organs
    .

References:
http://www.osha.gov/recordkeeping/new-osha300form1-1-04.pdf
www.osha.gov/recordkeeping/index.html
http://www.ninds.nih.gov/disorders/repetitive_motion/repetitive_motion.htm

copyright v hixson October 2011 - all rights reserved.
Virginia Hixson is a Certified Professional Ergonomist and Project Management Professional working in the San Francisco Bay Area.