Definition of Ergonomics is science of working tools and equipment adjustment to the conditions and human capacity, thereby achieving labor health and optimal productivity.
Ergonomics consists of two sub-chapter systems:
1. Working Tool Sub System
2. Human Sub System
The goal of ergonomics is to create the most harmonious combination between human sub-system and working tool sub-system.
The other goals are:
1. Preventing work accidents
2. Preventing inefficiencies work or increasing work productivity
3. Reducing the workload, because if the work equipment is not appropriate with the conditions and the size of the worker's body, it will be an additional burden of work.
Some ergonomic principles can be used as guidelines in the occupational health program:
1. Gesture in doing the work is strongly influenced by the shape, composition, size and placement of machines, instruction tools placement, ways of operating the machine (motion, direction, strength, etc.).
2. To normalize the machine size or work equipment, it must be taken the largest size as the basis, and arranged in a way, so that the size can be reduced and can be served by a smaller employee, for example, a seat that can be adjusted up and down, moved forward and backward.
3. Anthropometric sizes that can be used as the basis for work tools placement are as follows: (a). Stand: Height, Shoulder height, Elbow Height, Hips height, Arm lenght, (b). Sit: sitting height, upper Sleeve lenght, Forearm and Hand lenght, Dent Knee Distance.
4. At hand work in standing, working height should be 5-10 cm below the elbow height.
5. In terms of muscle, the best sitting posture is slightly bent, while in terms of bone, it is recommended to sit upright, so that no slouch back and no weak abdominal muscle.
6. Good Seating: (a). sitting height can be arranged by the foot board taht is appropriate with knee height, while tight is in the flat state, (b). board seat width is not less than 35 cm, (c). Back board height can be adjustable and press on the back.
7. Sight direction for standing work is 23-37 degrees downward, whereas for sitting work is between 32-44 degrees downward. Sight direction is appropriate with the state of the head rest.
8. The ability of maximum physical load by ILO is set at 50 pounds.
9. The working ability of a person is 8-10 hours per day. More than that, the efficiency and quality of work decrease.
