However, it is usually the case that workers are exposed to more than one risk factor at a time. This is the position that puts the least amount of physical strain on the particular part of the body. Postures that differ from the neutral position increase stress on the body. Figure 1 Overhead work, twisted or bent back, bent wrists, squatting or stooping are examples of body positions and movements that cause problems. See Figure 1.
Recovery is rest or a break from a risk factor.
Forceful movements include lifting a heavy object, unscrewing a rusted bolt, or squeezing an object in your hand. Another type of force, known as contact stress , comes from pressure against part of the body. For example, resting the wrists against the sharp edge of a desk while working at a computer puts pressure on the wrists. Exposure to vibration can affect particular parts of body, such as the hands, when using power tools. This is known as localized vibration.