WHILE ATTEMPTING TO ESCAPE FROM FALLING POWER LINES DUE TO TRACTOR OPERATOR HITTING GUY WIRE, EMPLOYEE JUMPED 3 FOOT OBSTRUCTION AND SUFFERED A SPRAIN/ STRAIN OF LEFT LOWER BACK. HE REMAINED ON REGULAR DUTY UNTIL 3/6/01 WHEN CONTINUED COMPLAINTS OF BACK DISCOMFORT RESULTED IN RESTRICTED DUTY.