EMPLOYEE REPORTED: WORKING IN THE FACE AREA HELPING ON THE CONTINUOUS MINER, WHEN ATTEMPTING TO HANG A WING CURTAIN, LOST HIS FOOTING AND SLIPPED. THE STUMBLE RESULTED IN TWISTING OF HIS RIGHT KNEE. HE CONTINUED TO EXPERIENCE PAIN TO THE KNEE. FIRST SOUGHT MEDICAL TREATMENT 2/9/2004. STARTED MISSING SCHEDULED WORK DAYS ON 2/25/2004.