Risk Factor - Repetitive Motions

A dragline operator uses repetitive motions to manipulate the joysticks that control the dragline movements. A complete cycle takes about 1 minute, so during a 12-hour shift approximately 720 cycles are completed.

Doing the same movements many times...

• Using equipment controls
• Machine paced assembly tasks
• Packing or unpacking items
• Quality control inspections
• Using computers (keyboard and mouse)

Repetitive motions are usually performed with small muscle groups, like your hand and finger muscles, and often do not have high force demands. The motions, or cycle times, can be repeated from every few seconds to every few minutes and are repeated for two or more continuous hours during the work shift. The more repetitive the motion, the more frequent the muscle contractions occur. When muscles contract repeatedly, fatigue may be experienced. Over a period of time, the repetitive motions, particularly when combined with excessive force or awkward posture, may lead to inflammation and soreness.

Examples of Repetitive Motions:

• Using equipment controls
• Using hand tools
• Computer use