EE WAS ASSIGNED TO DO REPAIRS TO THE #25 DUST COLLECTOR. IN ORDER TO DO THIS JOB, THE PLANT'S MANLIFT WAS USED TO GAIN ACCESS TO THE AREA. WITH EE IN THE MANLIFT, HE LIFTED A PIECE OF 10"" DU ST LINE (WEIGHING APPROX 30#). AS HE RAISED ON THE END OF THE DUST LINE FROM THE BASKET HE FELT A SUDDEN PAIN IN HIS RIGHT THUMB. EE CONTINUED TO WROK HIS SCHEDULED SHIFT.