According to the scientific literature, the following are recognized as important risk factors for musculosketal disorders, especially when occurring at high levels and in combination.

# Awkward postures

For example, more stress is placed on the spinal discs when lifting, lowering, or handling objects with the back bent or twisted, compared with when the back is straight. Manipulative or other tasks requiring repeated or sustained bending or twisting of the wrists, knees, hips, or shoulders also impose increased stresses on these joints.

# Forceful exertions (including lifting, pushing, and pulling) Tasks that require forceful exertions place higher loads on the muscles, tendons, ligaments, and joints. Increasing force means increasing body demands such as greater muscle exertion along with other physiological changes necessary to sustain an increased effort. Prolonged or recurrent experiences of this type can give rise to not only feelings of fatigue but may also lead to musculosketal problems when there is inadequate time for rest or recovery.

* increased bulkiness of the load handled or lifted,

* use of an awkward posture,

* the speeding up of movements, increased slipperiness of the objects handled (requiring increased grip force),

* the presence of vibration (e.g., localized vibration from power hand tools leads to use of an increased grip force),

* use of the index finger and thumb to forcefully grip an object (i.e., a pinch grip compared with gripping the object with your whole hand), and

* use of small or narrow tool handles that lessen grip capacity.

The Rising Repetitive Stress Injury (RSI) Epidemic

The Average Cost per incidence of RSI is now $12,000. This includes: Lost work with full wages, replacement wages, lost productivity, and medical treatment, not including surgery. RSI is now the leading workplace injury. If surgery is required, the average cost is $43,000 per incidence according to the American Society of Orthopedic Surgeons. In 1994, over 200,000 Carpal Tunnel Syndrome (CTS) operations were performed in the United States. The median jury award for carpal tunnel syndrome injury cases climbed 17% in 1996 to $52,610. Office related verdicts accounted for about five percent of the cases. (Personal Injury Verdict Reviews)