The issue before the Court in this case is whether the State Industrial Commission may, in a proceeding before it, admit reliable hearsay evidence into the record and whether that evidence is sufficient to support the commission’s decision. For reasons that will be discussed, we have concluded that the evidence was properly admitted and will support the decision reached by the commission in this case.
On June 9, 1970, the appellant, Donald L. Hite, was injured while in the employ of respondent Kulhenak Building Contractor. As a result of the accident, he suffered permanent partial loss of one arm and complete loss of his right kidney. A hearing was held before the State Industrial Commission. At the hearing, Dr. C. E. Groom, a urologist from Pocatello, testified on behalf of appellant that he had examined the appellant and rated the loss of one kidney as equivalent to seventy-five percent loss of one leg at the hip. The-loss of a leg at the hip is a scheduled loss under the workmen’s compensation law while the loss of a kidney is not. It is permissible to rate an unscheduled loss as being equivalent to part or all of a scheduled loss. I.C. § 72-313 (pre 1971 statute). This loss rating would have entitled appellant to receive a total of one hundred and thirty-five weeks of compensation under I.C. § 72-313.
Respondents called as a witness Dr. Gerald Hecker, a urologist from Boise, who testified that he also examined appellant and rated his loss of a kidney as equivalent to ten percent of the loss of a whole man. This would have entitled appellant to receive compensation for forty weeks. I.C. § 72-313. Dr. Hecker testified that after examining the appellant, he consulted the American Medical Association Guides to Evaluation of Permanent Impairment (1971), and that the figure found in the guides was the one he used. He also stated that the guides were prepared by experts in the field of medical disability rating and that his testimony was based entirely upon the guides, that he had no opinion of his own as to the proper rating. Over appellant’s objection, the guides were then introduced into evidence.
After reviewing the evidence, the commission ruled that appellant was entitled to twenty-four weeks of compensation at $43.-00 per week for the injury to his arm, which was based on ten percent loss of an arm at the shoulder. Appellant does not now question this ruling. The commission also ruled that the loss of a kidney is equivalent to ten percent loss of the whole man and awarded appellant forty weeks of compensation at $43.00 per week. It is from this decision that appellant has appealed.
In 1971, the Workmen’s Compensation Laws were extensively amended by the legislature. However, both under the pre 1971 laws (which are controlling in this case and will be relied upon in this opinion) and the post 1971 laws, the findings of the Industrial Commission as to the extent of disability are binding on this Court if supported by substantial, competent evidence, I.C. § 72-609 (a); and supported also by at least some professional evidence, Bottoms v. Pioneer Irrigation District, 95 Idaho 487, 511 P.2d 304 (1973). Appellant claims that there is no competent evidence in the record supporting the finding made by the commission because the guides upon which the finding is based are inadmissible hearsay evidence and that the commission erred in admitting them into evidence.
Appellant argues that medical books or treatises, such as the guides, are not admissible in Idaho courts as substantive proof, that they can only be used for purposes of cross. examination of expert medical witnesses. Cochran v. Gritman, 34 Idaho 654, 203 P. 289 (1921); Osborn v. Cary, 28 Idaho 89, 152 P. 473 (1915). And, according to appellant, the Industrial Commission *72is governed by the same rules of evidence as are courts of law. In re Black, 58 Idaho 803, 80 P.2d 24 (1938).
We need not decide whether medical books or treatises are admissible in Idaho courts as substantive proof, as respondent claims they are, because we do not feel that the Industrial Commission should be, or is, governed by the same rules of evidence as courts of law. The legislature, when it created the commission, intended that proceedings before it should be as summary, economical, and simple as the rules of equity would allow. I.C. § 72-601. As stated in Duggan v. Potlatch Forests, Inc., 92 Idaho 262, 263, 441 P.2d 172, 173 (1968):
“Proceedings under the Workmen’s Compensation Law are designed to afford employees a speedy, summary, and simple remedy for the recovery of compensation for injuries sustained in industrial accidents and are not governed so strictly by evidentiary and procedural rules as applied in courts of law. I.C. § 72-601; Walker v. Hogue, 67 Idaho 484, 185 P.2d 708 (1947); Pierstorff v. Gray’s Auto Shop, 58 Idaho 438, 74 P.2d 171 (1937); Feuling v. Farmers’ Co-op. Ditch Co., 54 Idaho 326, 31 P.2d 683 (1934); Kelley v. Prouty, 54 Idaho 225, 30 P.2d 769 (1934). However, the procedure of the Board must be ‘as far as possible in accordance with the rules of equity.’ I.C. § 72-601.”
By rules of equity, the statute means that although the proceeding must be as summary as possible, it must still be fair and do substantial justice to all parties involved. In re Bones, 48 Idaho 85, 280 P. 223 (1929); Pierstorff v. Gray’s Auto Shop, 58 Idaho 438, 74 P.2d 171 (1937).
In order to insure that the proceedings are kept simple, economical, and summary, the legislature established a procedure whereby claims could be heard by an administrative agency that possessed sufficient expertise to competently weigh the evidence and make a- speedy, just determination. Walker v. Hogue, supra. If the Industrial Commission was required to follow all of the rules of evidence and procedure found in courts of law, then to some extent at least, the intent of the legislature to provide for summary dispositions of claims would be frustrated and proceedings before the Commission would tend to become expensive and protracted affairs. The legislature therefore must have intended that the commission should have the discretionary power to consider any type of reliable, trustworthy evidence having probative value in the area of disability rating, even though that evidence may not be admissible in a court of law. So, in so much as In re Black, supra, may have stood for the principle that the Industrial Commission is governed by the same rules of evidence as are the courts of this state, we overrule that decision and conclude that in those areas in which the Industrial Commission possesses recognized expertise, it may in its discretion consider evidence not ordinarily admissible in a court of law.
The guides in question were prepared by committees of experts in the field of disability compensation. None of those experts had any interest in the outcome of this case. The guides are recognized authority in the area of disability rating. They are, in short, trustworthy and reliable. Of course, it will still be necessary to introduce the evidence through witnesses who must be able to testify that they are recognized authority. By our decision today, we are not holding that the Industrial Commission can take notice of anything it desires. Only, that recognized treatises or works dealing with topics in which the commission possesses expertise may be admitted into evidence through witnesses to be used as substantive evidence.
Since the guides were properly admitted into evidence by the commission, there is substantial, competent evidence in the record supporting their determination that the loss of one kidney is equivalent to the loss of ten percent of the whole man and that decision is therefore affirmed. Costs to respondent.
*73SHEPARD, C. J., and McQUADE, J., concur.