
    Argued and submitted December 16, 1985,
    affirmed May 14,1986
    In the Matter of the Compensation of George E. Johnson, Claimant. JOHNSON, Petitioner, v. ARGONAUT INSURANCE COMPANY et al, Respondents.
    
    (82-06854; CA A36179)
    719 P2d 30
    Philip F. Schuster, II, Portland, argued the cause and filed the brief for petitioner.
    Richard Wm. Davis, Portland, argued the cause for respondents. With him on the brief was Lindsay, Hart, Neil & Weigler, Portland.
    Before Richardson, Presiding Judge, Joseph, Chief Judge, and Warden, Judge.
    RICHARDSON, P. J.
   RICHARDSON, P. J.

The issue in this workers’ compensation case is whether claimant has proven an aggravation of his compensable low back injury. See ORS 656.273(1). The Workers’ Compensation Board found that claimant was not credible and therefore reversed the referee’s order, which had held that claimant had proved his claim. We affirm.

Although we agree with the Board that claimant’s credibility is suspect, it is not so weak that it completely undermines his claim. However, even assuming that claimant is credible, he has failed to prove his claim.

To establish an aggravation claim, a claimant must prove by a preponderance of the evidence a worsening of his condition since the last arrangement of compensation and a relationship between that worsening and his compensable injury. Hoke v. Libby, McNeil & Libby, 73 Or App 44, 46, 697 P2d 993 (1985). There is no objective evidence that claimant’s underlying back condition has worsened, but he has suffered an increase in pain. He need not prove a worsening of his underlying condition to prove his claim, Consolidated Freightways v. Foushee, 78 Or App 509, 717 P2d 633 (1986), but, in order for his increased pain to constitute an aggravation, he must prove that it has made him less able to work than he was at the time of the last arrangement of compensation. Consolidated Freightways v. Foushee, supra; Smith v. SAIF, 78 Or App 443, 717 P2d 218 (1986); Miller v. SAIF, 78 Or App 158, 714 P2d 1105 (1986); McElmurry v. Roseburg School District, 77 Or App 673, 714 P2d 264 (1986). On de novo review, we conclude that claimant has not proved that he is more disabled as a result of his pain.

Affirmed.  