the design of screw knobs of ergonomic shapes and sizes for pinch grip activities.
Several designs of screw knobs were designed and fabricated. The assessment of the knobs involved workers from a manufacturing firm.
The ratings on the efforts to pinch and turn the knobs were collected using surveys and analyzed with reliability and descriptive and analyses. The results show that the workers mostly preferred using the small 5-lobes knob. However, the large ball knob was the least preferred knob to be used. The findings of this study can be used to create design guidelines on knob shapes and sizes to develop safer, more ergonomic and efficient knobs.