WMSDs arise from ordinary arm and hand movements such as flexing, extending, gripping, twisting, reaching, etc. These movements are not particularly harmful in the ordinary activities of daily life. What makes them hazardous in work situations is the repetitious natre and lack of recovery time. An analogy is a rope sliding back and forth over an edge. If this motion is repeated, the rope becomes hot, worn and frayed. Muscles and tendons respond similarly when overused hour after hour, workday after workday. With time, the effort to maintain the repetitive movements, even if the forces involved are minimal, steadily increases. When the work activity is continued in spite of the developing fatigue, injuries occur. It is important for workers to find ways to reduce the stress on their bodies and ensure that their bodies are able to recover during the work day.