with whom COMPTON, Justice, joins dissenting.
The majority opinion concludes that Osborne Construction Co. failed to present sufficient affirmative evidence to rule out the work-relatedness of Jordan’s injury and therefore failed to overcome the presumption of compensability. I respectfully dissent because Jordan’s descriptions of how and when his radiating leg pain began, found in Jordan’s medical records, constitute “affirmative evidence” under Veco, Inc. v. Wolfer, 693 P.2d 865, 872 (Alaska 1985).
A majority of the Board concluded that “[t]he available medical records of the employee’s visits to the chiropractors and to Dr. Ha on March 19, 1990 all implicitly indicate that this back condition arose by the employee either playing basketball or moving furniture.” Thus, the Board found the medical records to be substantial affirmative evidence that Jordan’s condition was not work-related. It therefore concluded that Osborne had overcome the presumption of compensability. I agree with that conclusion.
Jordan experienced back pain in August 1989 while working for Osborne. He did not report the injury when it occurred, seek immediate medical treatment, or lose any time from work.
In March 1990 Jordan visited Dr. Young Ha complaining of a sudden onset of radiating pain in his left leg; that pain had started about a week earlier, shortly after he played basketball and moved furniture. He had recently moved from one residence to another. Dr. Ha’s notes of the visit state, “This pain started about eight days ago after playing basketball and moving furniture about an hour although he does not recall any specific incident in which he had any pain although he did feel some discomfort in his lower back.” The notes further state, “Late October [sic] 1989 he had back pain after pulling a plate compactor up from a slope at his work for Osborne Construction Company. However he did not have any leg pain and he did not lose any time from his work.” (Emphasis added.)
Jordan did not return to Dr. Ha, but in April 1990 visited Dr. G.F. Palmer, D.C., for “pains through lower back to calf.” Jordan’s wife filled out the new patient preliminary information questionnaire, which Jordan signed. Under “Patient Employed By:” Jordan named Osborne. Under “Date of Accident/Beginning of Illness,” Jordan wrote, “Beginning of March.” In response to “How did it occur? _Auto Collision_On-the-job _ Other,” Jordan wrote next to “Other,” “Carrying furniture.” After “PLEASE INDICATE WHICH KIND OF INSURANCE YOU HAVE: GROUP INSURANCE _ BLUE CROSS/BLUE SHIELD _ WORKER’S COMPENSATION _ AUTO INSURANCE _ MEDICARE _ PERSONAL INJURY _ OTHER INSURANCE Jordan checked “OTHER INSURANCE.”
Later that month, Jordan visited the Spaulding Chiropractic Clinic, whose new patient information form reveals similar information. Jordan filled out the two-page information form. Under “WHAT ARE YOUR MAIN PROBLEMS (AREAS OF PAIN)?— how long?” Jordan wrote “lower back and left leg — 5 weeks.” Under “HAVE YOU HAD SIMILAR ACCIDENTS/INJURIES?” Jordan checked “NO.” Under “PLEASE DESCRIBE THE CIRCUMSTANCES,” Jordan wrote “moving furniture.” Jordan stated that the “DATE OF THE ACCIDENT OR BEGINNING OF ILLNESS” was “3-13-90.” Under “IF ACCIDENT, HOW DID IT OCCUR? _ AUTO _ ON THE JOB _ OTHER,” Jordan checked “OTHER.” Under what type of insurance was the case covered by, Jordan selected “GROUP INSURANCE” and “PERSONAL INJURY,” rather than “WORKER’S COMPENSATION.” He also reported that he was employed by “Osborn [sic] Const.”
*394In May Jordan saw another orthopedic surgeon, Dr. Edwin Lindig, who noted in Jordan’s medical history that his condition arose after “moving in February.”
The Jordans’ oral and written accounts memorialized in the records of Drs. Ha, Palmer, and Spaulding do not mention any relationship between his August 1989 injury while employed by Osborne and the radiating pain that led him to seek treatment in 1990. Instead, they affirmatively deny a work-relationship and offer a non-employment explanation for how his radiating pain originated. A reasonable person could fairly find from that evidence that in 1990 Jordan suffered a new medical problem which was different from or more severe than the problem he experienced in 1989 as a result of his employment. Further, the current manifestation of his medical problem — herniations of three lumbar discs — was radiating pain, instead of the non-radiating pain he told Dr. Ha in 1990 he had experienced on the job six months before.
The medical history memorialized in these accounts is relevant evidence adequate to support a reasonable conclusion that the radiating pain Jordan experienced in March 1990 originated in recent, non-work-related activities. Substantial evidence is “such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.” Gillispie v. B & B Foodland, 881 P.2d 1106, 1109 (Alaska 1994) (emphasis added). Osborne’s presentation of Jordan’s medical accounts was therefore sufficient to rebut the presumption of compensability. The Board permissibly relied on substantial evidence which affirmatively and permissibly supports a non-employment explanation. Thus, I disagree with the majority’s conclusion that under Wolfer, Osborne failed to present sufficient affirmative evidence to eliminate the work-relatedness of Jordan’s injury. See Wolfer, 693 P.2d at 872 (concluding that the employer rebutted the presumption of com-pensability by presenting circumstantial evidence, coupled with the employee’s statements regarding his condition, to create a “reasonable inference” that the new injury was “merely a flare-up” of the earlier injury).
Although the medical history was insufficient to compel a conclusion that Jordan’s radiating pain was not related to his work, it was sufficient to overcome the presumption. Additionally, assuming Alaska Pacific Assurance Co. v. Turner, 611 P.2d 12 (Alaska 1980), applies, this evidence is also sufficient to permit a conclusion that the work-related injury was not a “substantial factor” contributing to the condition noted in March 1990. Id. at 14.
Having concluded that these medical records were sufficient to rebut the presumption, I would proceed to review the third stage of the Board’s analysis, in which it weighed all the evidence and concluded that Jordan had not proven his claim by a preponderance of the evidence.1 Because substantial evidence supports that conclusion of the Board, I would reverse and remand with instructions to reinstate the Board’s decision and order rejecting Jordan’s claim. See Resler v. Universal Services, Inc., 778 P.2d 1146, 1150 (Alaska 1989) (upholding Board’s determination that employee failed to prove claim by a preponderance of the evidence, considering that employee lacked credibility coupled with witnesses’ testimony).
. The Board denied workers' compensation benefits to Jordan, finding that the preponderance of the evidence indicates that Jordan’s condition "arose from incidents subsequent to his employment, and not in the course and scope of his work.” The Board found Jordan’s testimony not credible. It was “troubled by the inconsistency of the employee's history over time, the contradictions between his testimony and that of other witnesses, and by his admitted misrepresentation related to unemployment insurance.” Therefore, the Board concluded that it could not rely upon the later medical opinions which were based on Jordan’s “self-serving version of the events and symptoms.” Instead, the Board found Jordan’s initial version of his history, as reflected in the first medical reports, to be more credible.
"The [B]oard has the sole power to determine the credibility of a witness. A finding by the [B]oard concerning the weight to be accorded a witness's testimony, including medical testimony and reports, is conclusive even if the evidence is conflicting or susceptible to contrary conclusions.” AS 23.30.122.