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A safety meeting in a nutshell

CUMULATIVE TRAUMA DISORDERS FROM REPETITIVE MOTION

Note to Discussion Leader: Use the following information to develop your presentation. Make the material applicable to your operation to help your listeners relate to the message. Ask questions to draw out personal experiences from your participants. Share information that encourages awareness and application of sound accident-prevention principles. Use a common screwdriver as a visual tool to explain awkward hand positions.

Discussion Background Information

Ask people to perform the same rapid movements for long periods of time, and small injuries can accumulate in some parts of their bodies. These can build into an injury called a cumulative trauma disorder (CTD) and might require medical treatment. CTDs develop because:

Chronic restriction of blood flow to the tissues under stress is another factor in CTDs. One of the more common causes of CTD called carpal tunnel syndrome is the constant use of a poorly designed tool over a long period of time. Tool design for proper task position in relation to hand position is critical in preventing the stresses than can cause carpal tunnel syndrome.

The common screwdriver is a good example of repetitive motion in an awkward position. If you have used one for hours at a time or at work, you will know that there is no way to constantly use it without getting sore hands. Extended use every day for several months could lead to a repetitive motion injury. Brief use every day would not normally cause a CTD.

There have been several changes in the screwdriver in the last few years. The older screwdriver of the 1930s had a metal shank all the way through the wooden handle. That screwdriver was difficult to hold when it was wet or oily. Ribbed plastic handles or rubber-sleeved handles replaced the slippery type and provide a better grip. Angled handles and rachet screwdrivers were designed as a means to reduce the hand stresses. Air and electric-driven screwdrivers further reduce the stress on the user. Now, production plants use power-driven, pistolgrip screwdrivers or straight powered screwdrivers that have a suspended support.

Screwdriver Demonstration

The normal use position of a common screwdriver is with the hand in this position. (Show the position of the normal hand position of using a screwdriver.) You can't use it well in the straight position recommended to prevent CTDs. (Show the straight wrist position.)

Question: CTDs are known to be caused by combinations of frequency, awkward position, load stress and grip. Frequency of the task appears to be the most important factor in CTD development. What kinds of tasks here at work repeat the same hand or body motion several times per minute?

Answer: (Note: Use your injury review examples and any suggestions from the group to discuss how frequently tasks are done.)

Question: Are any of these tasks done from an awkward position?

Answer: Some awkward positions are: reaching above shoulder height, extending arms nearly as far as they can reach, twisting your shoulders, bending your elbow unnaturally or having to look up at the task from a standing or seated position. (To stimulate discussion, use the group's answers or use the screwdriver to demonstrate awkward hand positions.)

Question: The pressure or load on a body part is another important factor in CTDs. What kind of load or pressure is on the hand or body part when doing the repetitive motion tasks?

Answer: A secure hand hold is important in repetitive tasks. Poor gripping surfaces require more pressure. Weight, torque and push pressures are some that can add to the risk of in jury.

"TO DO" LIST:

-- from the Ohio Bureau of Workers' Compensation Safety Leaders Discussion Guide