The issue in this workers’ compensation case is the extent of claimant’s left shoulder disability. The referee concluded that claimant had failed to prove that his Weyerhaeuser employment had caused his present shoulder disability, because “his subsequent employment [with a different employer] contributed independently to his present shoulder condition.”1 The Board affirmed the referee’s order. On reconsideration, the Board explained that it had not affirmed on the basis of responsibility, but on the basis that claimant had failed to prove that there was “a material causal connection between his shoulder disability and his compensable injury.” We review de novo 2 and reverse in part.3
Claimant sustained injuries to his left shoulder, low back and left knee in April, 1980, while working for Weyerhaeuser. Those injuries were expressly accepted as compensable.4 In early May, 1980, he saw Dr. Freudenberg, an orthopedist, complaining of pain in the left shoulder, especially in the anterior aspect. Freudenberg diagnosed bicipital tendinitis. He continued to treat claimant for his knee injury, but made no mention of the shoulder injury after a chart note dated May 19.
Claimant later saw Dr. Matteri, another orthopedist, and Dr. Bert, also an orthopedist, for knee and back problems. No mention was made of the left shoulder in the medical notes until May 22, 1984, when Matteri noted that claimant had complained about pain around the medial aspect of the scapula and tingling in two fingers. Matteri administered a *55steroid on that date. His notes say that the shoulder problem “dates back to [claimant’s] 1980 accident.”
Claimant next sought treatment for his shoulder on October 23 and November 12, 1984, from Dr. Hearne, an internist. His chart notes indicate that claimant injured the shoulder in an industrial accident in April, 1984, and that later he had been seen by an orthopedist in Eugene. He diagnosed “[l]eft trapezius muscle pain, etiology unclear.” He saw claimant again on August 20,1985, when claimant was experiencing “left paracervical pain with radiation to the shoulder.” He referred claimant to Dr. Bernstein, a neurologist, for further evaluation, noting that the symptoms were “suggestive of nerve root damage.”5
In a letter to Hearne dated August 26, Bernstein noted that claimant’s history was “complex,” but cited only the April, 1980, injury. He diagnosed “[p]robable shoulder strain with a ‘functional’ thoracic outlet syndrome.” Claimant saw Bernstein two more times in 1985. Bernstein testified by deposition that he believes that there is a causal connection between the 1980 injury and claimant’s present shoulder problems. He also answered “yes,” in writing, to the question whether claimant’s physical limitations in 1986, including limitations on the use of his arms, were a result of the 1980 low back and shoulder injury to claimant.
As noted, the Board found that claimant had failed to prove that his compensable injury at Weyerhaeuser caused his present shoulder disability. Employer argues that later work exposures are the cause. Although the question is close, we disagree with the Board and with employer6 and find that *56claimant’s 1980 injury is a material contributing cause of his present shoulder disability. ORS 656.214(5); Destael v. Nicolai Co., 80 Or App 596, 600, 723 P2d 348 (1986).
Reversed in part and remanded to determine the extent of disability; otherwise affirmed.