WHILE OPERATING THE TAILGATE END OF THE SHEAR CUTTING COAL TOWRDS THE TAILGATE OF THE LONGWALL FACE, A BOUNCE IN THE FLOOR OCCURRED. THIS KNOCKED THE INDIVIDUAL DOWN WHERE HE STRUCK HIS HEAD A ND UPPER LEFT BACK ON BAS LIFT CYLINDER BRACKET. THIS CAUSED A BUMP ON HIS HEAD AND XRAYS SHOWED A SMALL PIECE OF BONE CHIPPED OFF THE END OF THE PROCESS OF HIS T-1 VERTEBRA.