Schmidt

We review a decision of respondent Workers’ Compensation Appeals Board (Board) that 80 percent of petitioner’s permanent disability should be apportioned to preexisting disability. Because we agree with petitioner that the evidence does not support apportionment, we will annul the Board’s order after reconsideration.

Factual and Procedural History

Petitioner’s employment with respondent City and County of San Francisco (city) commenced in approximately 1974. In 1980, he was a firefighter when he experienced back pain while lifting a large hose. He was off work about six weeks. When he returned to work, he returned as an airport police officer, a position he held before his firefighting position. When getting up from a chair while at work in 1986 and again in 1988, he experienced pain and spasm in his lower back. He was treated for each of these incidents and the symptoms subsided. No work restrictions followed these incidents of back pain.

On December 16, 1989, petitioner experienced an acute episode of back pain when he bent over at a drinking fountain at work. He was treated by Dr. Owen who on one or two occasions recommended that he return to light work with limited…