A COMPARATIVE-STUDY OF 2 SHOVEL DESIGNS

In the present study a modified shovel design with two perpendicular s hafts is presented. This modified, two-shaft shovel was compared with a regular shovel. The modified shovel was evaluated and tested in a co ntrolled laboratory environment using surface electromyography recorde d from the lumbar paraspinal muscles. The new shovel design was also t ested in a field study using ratings of perceived exertion. The result s indicate that there was a significant reduction in EMG values of the lumbar paraspinal muscles and a consistent reduction in perceived exe rtion ratings while the modified shovel was being used for removing di rt in digging trenches up to 90 cm in depth.