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RSI Handbook: Glossary

Acute Trauma - an injury such as a bone fracture that has an immediate and easily identified cause. Pain and/or other health effect is also immediate.

Artery - a blood vessel that carries oxygen-rich blood from the heart to the rest of the body.

Arthritis - inflammation of a joint (knee, hip, shoulder, fingers are all joints which can become arthritic).

Awkward Posture - body posture that can increase the risk of Repetitive Stress Injuries.

Blood Vessel - an artery, vein or capillary through which blood flows, either from the heart to the tissues (arteries) or from the tissues back to the heart (veins).

Brain - the main part of the nervous system (which also includes the spinal cord and nerves).The brain regulates all of the body’s activities. (The brain is the part of the body which when used will save wear and tear on the rest of your body.)

Capillary - a tiny blood vessel with thin walls. Nutrients and oxygen leave the blood through the walls of capillaries to feed the body’s cells.

Cardiovascular System - the system that circulates blood through the body; includes the heart and blood vessels (arteries, veins, capillaries).

Carpal Tunnel Syndrome - painful wrist/hand repetitive stress injury in which inflamed tendon squeezes nerve against bone in wrist. Symptoms include tingling and numbness in hand. If not treated, permanent damage, including muscle weakness, can result.

Cartilage - tissue found between vertebrae and at the ends of bones at the joints. Cartilage can withstand a lot of tension and pressure.

Chronic Low Back Pain - soreness, fatigue of the low back.

Compressive Force - pressure that acts to compact or squeeze together parts of the body. Even the body’s own weight puts compressive force on the spine.

Constriction of  Blood Vessels - blood vessels can be squeezed, compressed or shrink so that it is hard for the blood to flow through the vessels. Reduced blood flow means less nourishment for the cells past the constriction.

Contraction (muscle) - when a muscle is used, it shortens and thickens (contraction) then relaxes and becomes longer and slimmer.

Degenerative Disc Disease - breakdown of the discs (which act as shock absorbers) that separate the vertebrae.

Disc - composed of cartilage with a gel-like center, discs separate one vertebrae from the next, and act as shock absorbers to help resist compression of the spine.

Dynamic Work - involves movement of the muscles. For example, when you hammer, your biceps and triceps are dynamic. (See Static Work.)

Energy - the capacity to do a certain activity. Some activities, such as carrying, lifting, climbing require a lot of energy.

Engineering Control - redesigning equipment, tools, work organization and workplaces to reduce workers’ exposures to factors that cause harm.

Epicondylitis - inflammation of tendons at the elbow (known as tennis or golfer’s elbow).

Ergonomics - the study of how work, the workplace and the worker all relate to each other. The goal of ergonomics is to fit the work and workplace to the person.

External Contact Stress - direct pressure from tools and sharp edges on soft tissues (for example, palm of the hand) can damage blood vessels and nerves.

Fatigue - tiredness that results when there is not enough rest and recovery time for the body to recover from work. Depending upon the activity, the fatigue may be in a muscle or group of muscles (localized muscle fatigue) or the whole body (whole body fatigue).

Force Requirements - the amount of effort needed to lift, push, pull, hold objects or operate a tool.

Hand-Arm Vibration - vibration (generally from a hand tool) that goes through the hand, then travels through the rest of the body.

Heavy Physical Work - work that uses a high level of energy. Lifting, carrying, pushing, pulling, climbing are all examples of heavy physical work.

Inflammation - the body’s reaction to injury. A repair process that produces pain, swelling, redness.

Joint - the place where two bones meet knee, elbow, fingers, etc.

Ligament - tough, strong tissue that attaches one bone to the next across a joint.

Localized Muscle Fatigue - occurs in a specific muscle or muscle group or groups.

Median Nerve - an important nerve that goes down the arm from the neck to the thumb, index and middle fingers and near side of ring finger. It is the median nerve that gets squeezed in carpal tunnel syndrome.

Muscle Cramp - sudden painful contraction of a muscle; usually caused by overuse (without rest), strain, chill.

Muscle Force - the effort need to move, lift, hold an object or tool or keep a posture without moving much.

Musculoskeletal System - the skeleton (bones), cartilage, ligaments, tendons and muscles that support us.

Nervous System - the brain, spinal cord and nerves — coordinates all body activities.

NIOSH - National Institute for Occupational Safety and Health. A government agency that researches workers’ health and safety issues.

Pinch Grip - gripping an object between the fingertips. A pinch grip, which uses small muscles of hand requires much more strength than a power grip (see below).

Power Grip - gripping an object by wrapping the whole hand around it so the thumb and finger tip are touching each other (for example, gripping a hammer).Uses large muscles of arm; has about four times the strength of a pinch grip.

Repetitive Stress Injuries (RSIs) - disorders of the muscles, tendons, nerves and blood vessels caused by repeated forceful exertions. It can take some time before pain or dysfunction appear. (Also called overuse or Cumulative Trauma Disorder [CTD].)

Reynaud’s Phenomenon - also called “white fingers” or hand-arm vibration syndrome. Use of vibrating tools (for example, a rotary hammer) constricts blood vessels in hand, preventing tissues in fingertips from getting enough blood, oxygen and nutrients. Fingertips turn white and painful, especially in the cold.

Risk Factor (work-related) - a part of a job that increases the worker’s chance of getting an illness or injury. For musculoskeletal disorders risk factors include forcefulness, awkward postures and repetitive motions.

Rotator Cuff Tendinitis - Inflammation of a tendon or tendons in the shoulder. Also called “Pitcher’s Shoulder.”

Sheath - the covering around a tendon. Sometimes it is the sheath and not the tendon that gets inflamed (see tenosynovitis below).

Spinal Column - the channel made up of vertebrae held together by ligaments and muscles. (See spinal cord below).

Spinal Cord - the cord of nerve tissue that comes from the base of the brain, through the spinal column down the back. Major nerves branch off the spinal cord.

Sprain - overstretching or tearing of a ligament. Sprains are generally acute traumas (for example, a “twisted” sprained ankle).

Static Work - In static work, the worker holds a body position (for example, working bent over) for long periods of time without moving much. Static work is very tiring. (See Dynamic Work.)

Strain - an injury, usually to the muscle, caused by too much force or overuse.

Strip Trigger - a trigger that can be used by two or more fingers at a time. Strip triggers are less stressful than single-finger triggers which can cause “trigger finger” (an inflammation of finger tendon or its covering).

Tendinitis - inflammation of a tendon. Tennis elbow is tendinitis of the elbow; pitcher’s shoulder is tendinitis of the shoulder.

Tendon - tough, rope-like tissue that usually attaches muscles to bones.

Tenosynovitis - inflammation of the sheath (covering) of a tendon. When the sheath is inflamed it becomes difficult for the tendon to move.

Trigger Finger - tendinitis or tenosynovitis (see above) of a finger (or fingers or thumb) caused by repeated triggering of a tool or forcefully holding fingers in one position. It becomes hard to straighten finger.

Upper Extremity - entire area from the neck to the fingertips, including shoulders, arms, elbows and hands.

Vein - blood vessel that carries blood from the body cells back to the heart to pick up more oxygen.

Vertebra - one of the 33 bones that form the spinal column.

Whole Body Fatigue - when physical demands on your body exceed your capacity your heart beats faster, you breathe faster, you feel hot, uncomfortable and may sweat.

Whole Body Vibration - heavy equipment operators and bus drivers are exposed to this. Over time, the vibration can cause small traumas to the spine.

Workload - the physical effort needed to do a job.


  • anc_dyn_linksRepetitive Stress Injury Handbook: Introduction
  • anc_dyn_linksRSI Handbook: What are RSIs?
  • anc_dyn_linksRSI Handbook: Types of RSIs
  • anc_dyn_linksRSI Handbook: What you can do to prevent injuries and illnesses
  • anc_dyn_linksRSI Handbook: Job risks
  • anc_dyn_linksRSI Handbook: Health and Safety Committees
  • anc_dyn_linksRSI Handbook: Your legal rights
  • anc_dyn_linksRSI Handbook: Resources
  • anc_dyn_linksRSI Handbook: Glossary