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The Concepts of Four-handed Dentistry Including Ergonomic Instrument Transfer and Exercises for Stress Reduction

Course Number: 643

Principles of Motion Economy

Motion economy refers to the way in which human energy is conserved while performing a task. The objective in all areas of the dental office, clinical, business or laboratory setting should be to minimize the number and magnitude of motions and conserve energy while working. Ask yourself the following questions:

  1. How many times do you turn your body or reach for an instrument? Does the assistant eliminate operator stress by transferring the instruments and materials to the operator?

  2. Does the assistant have primary responsibility for transfer of materials and instruments or is the assistant often unoccupied while the dentist reaches for an instrument or changes a bur?

  3. Are the handpieces and instruments within a 21-inch radius of the assistant?

  4. Are these same ergonomic concepts applied to the dental business office to minimize unnecessary motion and reduce stress?


    Examine the dental assistant’s daily activities and decide how modifications can be implemented to the routine to reduce motion. Planning during treatment room set-up is important to ensure all materials are prepared in advance in a motion effective environment. If the chairside assistant did not organize the set-up, it will be necessary for them to adjust or rearrange materials to achieve this goal. In the business office, it is important to examine the location of equipment and modify the location as necessary to reduce the need to reach or strain the body to gain access to commonly used materials and equipment.