Appeal from a decision of the Workers’ Compensation Board, filed December 3, 2004, which ruled that claimant’s workers’ compensation award be apportioned 50% to a nonwork-related injury and 50% to a work-related injury.
In 1986, claimant sustained a nonwork-related injury to her left knee while performing gymnastics in high school. She subsequently underwent reconstructive surgery to address this injury in 1993. Claimant worked without disability or restrictions until February 12, 2002, when she slipped in her employer’s cafeteria and reinjured her left knee. She thereafter applied for workers’ compensation benefits. A Workers’ Compensation Law Judge (hereinafter WCLJ) established the case for a left knee injury, but reserved on the issue of apportionment. Following hearings, the WCLJ found that apportionment of the award to the 1986 injury was not appropriate notwithstanding testimony from the employer’s independent medical expert to *837the effect that 50% of claimant’s disability was attributable to the prior injury and 50% was attributable to the 2002 injury. Upon review, the Workers’ Compensation Board reversed the WCLJ and directed that claimant’s award be so apportioned. Claimant now appeals.
We begin with the general rule that “apportionment is not appropriate where the claimant’s prior condition was not the result of a compensable injury and such claimant was fully employed and able to effectively perform his or her duties despite the noncompensable preexisting condition” (Matter of Bruno v Kelly Temp Serv., 301 AD2d 730, 731 [2003]). The determinative issue in such cases is whether the claimant’s prior condition “constitutes ‘a disability in a compensation sense’ ” (Matter of Krebs v Town of Ithaca, 293 AD2d 883, 884 [2002], lv denied 100 NY2d 501 [2003], quoting Matter of Carbonaro v Chinatown Sea Food, 55 AD2d 756, 757 [1976]). Here, claimant relies on the general rule in arguing that the Board’s determination is contrary to prevailing case law.
In reviewing claimant’s claim, however, the Board did not consider it to be a “traditional apportionment case[ ].” Rather, the Board found that this case involved the narrow situation where the prior nonwork-related injury would have resulted in a schedule loss of use award had the injury occurred in a work environment (see Trathen Logging Co., Inc., 2003 WL 21545736, 2003 NY Wrk Comp LEXIS 84158 [July 8, 2003]; see also Erie County Med. Ctr., 2005 WL 1794456, 2005 NY Wrk Comp LEXIS 6297 [July 26, 2005]; Best Fire, 2004 WL 1045123, 2004 NY Wrk Comp LEXIS 10172 [May 4, 2004]; Valeo, 2004 WL 291836, 2004 NY Wrk Comp LEXIS 7407 [Feb. 9, 2004]). Since schedule loss of use awards are intended to compensate for the diminution in future earning capacity (see e.g. Matter of Landgrebe v County of Westchester, 57 NY2d 1, 10 [1982]), the Board reasoned that a nonwork-related injury which would have resulted in a schedule loss of use award, had it occurred in the work environment, is “a disability in a compensation sense sufficient to warrant a finding of apportionment.” We defer to this interpretation of the Workers’ Compensation Law by the Board since it is not irrational (see generally Kurcsics v Merchants Mut. Ins. Co., 49 NY2d 451, 459 [1980]).
As to the dissent’s argument that the Board never made a schedule loss of use award for the second work-related injury, it is clear from the record that the only issue presented for Board review was the dispute over apportionment of the medical expenses for the second surgery. Thus, it was never asked to make a schedule loss of use award. There can be no doubt, however, *838that the Board found this case to be one which fell in the small subset of cases involving schedule loss of use awards. Indeed, the Board, in making its determination, noted that “in schedule loss of use cases [the question] is whether there is medical evidence of a pre-existing loss of use, range of motion or function of the body part in question which would have resulted in a schedule loss of use finding had the prior injury been compensable.” In justifying its holding, the Board added the following observation: “[T]here exists a sound reason to employ this inquiry in schedule loss of use determinations. A carrier should not be made to pay any portion of a schedule loss of use award attributable to a pre-existing loss of range of motion.”
Furthermore, this Court has never held as a matter of law that apportionment cannot be applied where the prior nonworkrelated injury would have resulted in a schedule loss of use award had the injury been work related. In this regard, the precedent cited by the dissent (see Matter of Edmondson v State Ins. Fund, 162 AD2d 833, 834 [1990]; Matter of Roselli v Middletown School Dist., 144 AD2d 223, 224 [1988]; Matter of Zanetti v Orange & Rockland Util., 132 AD2d 761, 761-762 [1987]) simply involves the question of whether substantial evidence supported those determinations in the face of disputed medical testimony. Here, both the independent medical expert and claimant’s own treating physician opined that there would have been a schedule loss of use award following the 1993 surgery had the prior injury been work related. Therefore, the Board’s determination should be upheld under Trathen Logging Co., Inc. (supra) and its progeny.
Crew III, Spain and Lahtinen, JJ., concur.