DeQuervain's Disease: Constriction of the tendon sheath on the side of the wrist and at the base of the thumb that results in pain.

Dynamic Effort: Characterized by an alternation of contraction and extension, tension and relaxation of a muscle.

Electromyogram (EMG):  Recording of the electrically activity of a muscle.

Epicondylitis: Tendonitis at the elbow.

Ergonomics: The study of the interaction between human beings, the objects they use and the environments in which they function.

Ergonomic Risk Factors: Awkward (Non-Neutral) postures, static muscle loading, repetition, force, contact pressure, and vibration.

Extension: An unbending movement that increases the angle between the bones of the limb at a joint.

Flexion: A bending movement that decreases the angle between the bones of the limb at a joint.

Fascia: A sheet of connective tissue covering or binding together body structures.

Force: The load, in pounds of pressure, put on the body.

Ganglion Cyst: Occurs when a tendon sheath swells up with synovial fluid and causes a bump under the skin.

Golfers Elbow: Medial (at the inside of the elbow) epicondylitis. See epicondylitis

Isometric Work: When a muscle contracts and exerts a force against resistance without producing any motion.

Isotonic: Muscle contraction in the absence of resistance.

Ischial Tuberosities: Two bony prominences forming the lowest point of the pelvis. When in a seated position our weight rests on them.

Kinesiology: The study of human movements as a function of the construction of the musculoskeletal system.

Kinetics: The branch of mechanics that deals with the motion of a body under the action of given forces.

Kyphosis: Convexity of the spine, as observed in the mid back region.

Lateral: Related to the side.

Ligament: Connective tissues attaching bone to bone.

Lordosis: Concave curvature of the spine, which exist in the neck and low back regions.

Lumbosacral Joint: Joint between the 5th lumbar vertebra and sacrum.

Median Nerve: Nerve from the neck that activates muscles that pronate the forearm and flex forearm, wrists, and fingers while also providing sensory feedback for the thumb and first two and one-half fingers.

Medial: Related to the middle.

Musculoskeletal Disorders:  Disorders that involve the muscles, tendons, ligaments, joints, blood vessels and/or nerves. These disorders include, but are not limited to; tendonitis, epicondylitis, carpal tunnel syndrome, low back strain and DeQuervain's disease.

Muscle Recovery: Muscles and other soft tissues must have the appropriate time to rest and relax and replace oxygen, sugars and nutrients to avoid fatigue and tissue damage.

Neutral Posture: The absence of flexion, extension and deviation of a joint.

Nerve Compression: External pressure on a nerve resulting in symptoms of tingling, numbness and loss of sensation.

Pronation: Medial rotation of the forearm that brings the palm of the hand downward.

Radial Deviation: Bending the wrist toward the thumb.

Range of Motion: The degree of movement that a body segment has at a joint.

Repetitive Work: Occurs if the cycle time for an activity is less than 30 seconds, or if more than 50% of the cycle time involves performing the same motion.

Risk: To expose to hazard or danger. It is a function of the frequency, duration and intensity of an exposure.

Strain: When tendon fibers are completely or partially torn apart or frayed. See tendon.

Sprain: When ligament tissue is torn completely or partially from the bone. See ligament.

Stress: A physical, cognitive or emotional load.

Static Effort: Characterized by a prolonged state of muscle contraction. According to Kroemer and Grandjean static effort is said to be considerable if a high level of effort is maintained for 10 seconds or more, if moderate effort persists for 1 minute of more and if slight effort lasts for 5 minutes of more.

Static Work: Work that occurs when effort must be made to hold the body in a prolonged position.

Supination: Lateral rotation of the forearm that brings the palm of the hand upward

Tendon: Connective tissue attaching muscle to bone

Tendonitis: Inflammation of the tendon.

Tendon Sheaths: Tubular structures through which tendons run. They are lined with a synovial membrane and, therefore, not only guide but also lubricate the tendons.

Tenosynovitis: Inflammation of the tendon sheaths.

Tennis Elbow: Lateral (at the outside of the elbow) epicondylitis. See epicondylitis.

Thoracic Outlet Syndrome: Compression of the nerves and blood vessels between the neck and shoulder that results in numbness in the fingers of the hand.

Ulnar Nerve: The ulnar nerve is the nerve that supplies part of the cutaneous nerves to the hand that innervates the area of the small finger and the lateral half of fourth digit. It also supplies for the motor innervations of the small muscles for the adduction of the fingers.

Ulnar Deviation: Bending the wrist toward the little finger.

Vibration Syndrome: Closure of the digital arteries in response to tissues being exposed to vibration.

Work: The amount of energy required to move a body and the body's load from one position to another.