EE was moving a bolter from 2 to 3 in the LOC. As they came into 3 entry EE tried to go under the line curtain and it became caught on the operator's deck canopy. EE then reached outside of the canopy and attempted to hold the curtain up while they moved the bolter. Then EE accidentally hit the wrong lever, causing EE to pinch their right arm between the bolter canopy and the rib.