dissenting.
Because the majority errs in concluding “that the Board’s order is supported by substantial evidence,” I dissent.
ORS 656.005(7)(a)(B) provides:
“If an otherwise compensable injury combines at any time with a preexisting condition to cause or prolong disability or a need for treatment, the combined condition is compensable only if, so long as and to the extent that the otherwise compensable injury is the major contributing cause of the disability of the combined condition or the major contributing cause of the need for treatment of the combined condition.” (Emphasis added.)
The only issue presented is whether the injury claimant sustained in the course of her duties as a teacher on September 26, 1996, while restraining an out-of-control student was the major contributing cause of her need for treatment. The only material medical evidence on this issue, as the majority concedes, is that of Dr. Waller, who stated in his report of November 26,1996:
“The event that led to the need for surgery was the control of a unruly student when she [claimant] developed a profound exacerbation of the left-sided neck and shoulder pain that became incapacitating. This prompted a new MRI scan. It was difficult for me to tell if there was actually any *329anatomical worsening between the two studies, but her symptoms certainly did.
“Therefore, I would state that she had a pre-existing condition that was producing fairly minimal symptomatology, certainly not to the point that surgery was being considered, until the event with the unruly student. Therefore I believe that event should be considered the major contributing cause to the need for surgery.”
In his deposition, Waller testified:
“* * * I couldn’t tell if there was any anatomical worsening between the new and the old MR[I] scans, but it was the precipitation of symptoms provoked by the control of an unruly student that prompted the need for surgery.”
As the majority points out:
“[T]he question of what is the major contributing cause of claimant’s need for treatment involves a complex medical opinion, the Board must rely on expert medical evidence in making that determination.” 164 Or App at 325.
Then, the majority joins with the Board in disregarding the only real evidence on that question. In its last sentence, the majority refers to “other medical evidence in the record,” without telling us what that evidence is; the majority has already told us that the only other medical evidence, that of Dr. Soot and Dr. Zivin, is of no help.
The majority cites both SAIF v. Strubel, 161 Or App 516, 984 P2d 903 (1999), and Worldmark The Club v. Travis, 161 Or App 644, 984 P2d 898 (1999), apparently without reading those decisions closely. In both, there was other medical evidence bearing on the issue of the claimants’ need for treatment, and in both this court concluded that the Board could find that the injuries were the major contributing cause of the claimant’s disabilities or the need for treatment. Here, there is no contrary evidence, but the majority would affirm the Board’s conclusion that claimant has not “established that the work injury was the major contributing cause of the disability or need for treatment * * Waller’s letter and deposition testimony cannot be read to support anything but the contrary conclusion. His is the only competent material *330medical evidence on the issue, and it is contrary to the Board’s conclusion that this majority affirms.
The majority, agreeing with the Board on what both see as critical, states that Waller “did not directly discuss the contribution of the preexisting condition versus the work injury to the need for treatment.”
Waller had a complete and accurate history of claimant’s neck problems. He clearly was aware of claimant’s preexisting condition when he concluded that the injury was the major contributing cause of the need for treatment. His awareness of that condition came both from the November 14 letter from counsel, and from the information provided for his deposition. As discussed in the majority opinion and quoted above, Waller was specifically asked in the letter from counsel if the major cause of the need for surgery was the work injury or the preexisting condition. He answered that the event with the unruly student “should be considered the major contributing cause to the need for surgery.”
The Board’s conclusion that Waller failed to weigh the relative contributions of the different causes was not supported by substantial evidence. Accordingly, the Board erred in holding that claimant’s work injury was not the major contributing cause of her need for treatment.
For all of the above reasons, I respectfully dissent.