Principles of Motion Economy (Q7)
The principles of motion economy can be classified into four groups:
Use of Human Body
- The two hands should begin motions at the same time.
- The two hands should not be idle at the same time except during rest periods.
- Motions of the arms should be made in opposite and symmetrical directions and should be made simultaneously
- Hand motions should be confined to the lowest classification with which it is possible to perform the work satisfactorily:
- Finger motions
- Wrist motions
- Forearm motions
- Upper arm motions
- Shoulder motions
- Momentum should be employed to assist the worker whenever possible, and it should be reduced to a minimum if it must be overcome by muscular effort.
- Smooth continuous motions of the hands are preferable to zigzag motions or straight-line motions involving sudden and sharp changes in direction.
- Ballistic (i.e. free swinging) movements are faster, easier and more accurate than restricted or controlled movements.
Arrangement of the Work Place
- There should be a definite and fixed place for all tools and materials.
- Tools, materials, and controls should be located close in and directly in front of the operator.
- Drop delivers should be used whenever possible.
- Materials and tools should be located to permit the best sequence of motions.
- Arrange the height of the workplace and chair for alternate sitting and standing, when possible.
- Provide a chair of the type and height to permit good posture.
Design of Tools and Equipment
- Combine tools whenever possible.
- Preposition tools and materials.
- Where each finger performs some specific movement, the load should be distributed in accordance with the inherent capacities of the fingers.
- For light assembly, a screwdriver handle should be smaller at the bottom.
- Momentum should be used to help the worker in doing their task not to increase their task.
- Even a temporary delay of work by a man or machine should not be encouraged.
- Machine should not run idle, it is not desirable that a lathe machine is running and its job is rotating but no cut is being taken.
- Two or more jobs should be worked upon at the same time or two or more operations should be carried out on a job simultaneously if possible.
- Number of motion involved in completing a job should be minimized.
Last modified: Thursday, 3 September 2020, 3:50 PM