A three-part series by The Associated PressSunday: Late pay raises mean jumps in pension benefits under some state-funded plans.Monday: Medical benefits tied to retirement system threaten local government finances.Today: A look at government workers who retire on disability and then return to physically demanding activities.On a good day of golf, Ken Brunette will shoot just a few strokes over par. On a bad outing, Odin Rondestvedt will stray into the 100s. Jack Gilbert typically averages a bogey per hole. While their scores and favorite golf courses may differ, the three men also share a lot in common: They are former Seattle firefighters, deemed disabled by a local board and now drawing tax-free benefits from the state.Brunette, Rondestvedt and Gilbert are just three of more than 3,000 Washington state members of an old pension system who have joined in a procession of disability retirements over the years — often due to back ailments. With lenient definitions of what qualifies as a disability and little effort to monitor the ailments, some have gone on to play sports and take other physically demanding jobs without any impact on their benefits.Nowhere is that trend more apparent than at the Seattle Fire Department, where the extent of the disability plague among that group of firefighters is particularly extreme, especially when compared with neighboring cities, Seattle police officers and even other Seattle Fire retirees who are part of a newer pension system.More than 88 percent of the Seattle Fire retirees in the so-called LEOFF-1 system are on disability retirement, according to an Associated Press analysis of pension records conducted as part of a two-year investigation of the system. That disability rate rises to 95 percent if you remove a small group of Seattle firefighters who served for more than 30 years, which is around the time when it starts becoming more lucrative for a typical retiree to depart on regular retirement.