I respectfully dissent.
The Workers’ Compensation Appeals Board (Board) granted reconsideration and rerated applicant’s disability based upon a restriction to “light work.”
In my opinion the restriction to “light work” is supported by substantial evidence. The independent medical examiner, Dr. Arthur Mead, *223testified that in his opinion applicant’s disability limited him to “light work.” The Board found that Dr. Mead’s testimony otherwise demonstrated that he was familiar with the guidelines’ definition of “light work” and rerated applicant’s disability accordingly.
The majority concede that the expert opinion of one physician may constitute substantial evidence supporting a determination of the Board. However, they have in effect reweighed the evidence and concluded that Dr. Mead’s testimony does not demonstrate that he understood the guidelines’ definition of “light work.”
In my opinion the evidence supports the Board’s finding with respect to the significance of Dr. Mead’s testimony. The Board’s guidelines for work capacity define “light work” as follows: “Disability resulting in limitation to light work contemplates the individual can do work in a standing or walking position, with a minimum of demands for physical effort.”
Dr. Mead testified, inter alia, that applicant’s condition would be aggravated by normal pressure on or continued stretching of the right buttock sciatic mechanism; that aggravation could result from applicant’s wearing his gunbelt or sitting against any object that might press against the injured area; that applicant should avoid walking stairs, climbing ladders or running, although he might walk on a level surface. Dr. Mead also testified that in order to avoid aggravation applicant should spend approximately half his time sitting and half standing, and that applicant should be in a work situation where he could sit or stand alternatively as the pain in his hip dictates. This testimony is entirely consistent with the guidelines’ definition of “light work” and supports the doctor’s statement that he was using the term “light work,” as language of art as used in the Board’s guidelines. Moreover, it provides evidence supportive of the doctor’s conclusion that applicant’s disability restricted him to “light work.”
It is the function of the reviewing court to examine the entire record to determine whether the conclusion of the Workers’ Compensation Appeals Board was supported by substantial evidence. (Lab. Code, § 5952; LeVesque v. Workmen’s Comp. App. Bd. (1970) 1 Cal.3d 627, 637 [83 Cal.Rptr. 208, 463 P.2d 432]. The substantial evidence rule does not permit this court to reweigh the evidence and substitute its judgment for the judgment of the Board. It may not isolate and accept what it perceives as conflicting evidence and disregard supportive evidence. *224Furthermore, it is not the proper function of this court to independently weigh the conflicting evidence against the evidence supporting the Board’s decision. Rather, it is the duty of the reviewing court to determine from the whole record whether the conflicting evidence so discredits the supportive evidence as to render it insubstantial. (Mendoza v. Workers’ Comp. Appeals Bd. (1976) 54 Cal.App.3d 820, 823 [127 Cal.Rptr. 173]. Dr. Mead’s opinion was not discredited. His testimony provides substantial evidence in support of the Board’s determination in this case.
The petition of respondent Taylor for a hearing by the Supreme Court was denied May 12, 1982. Bird, C. J., was of thé opinion that the petition should be granted.