A writ of mandamus is an extraordinary remedy, and the burden of showing a clear legal right to this writ as a remedy from a determination by the Industrial Commission of the extent of claimant’s injury is upon relator. See, generally, State, ex rel. Pressley, v. Indus. Comm. (1967), 11 Ohio St. 2d 141. “It is well established that mandamus will not lie where there is some evidence to support the finding of the Industrial Commission.. See State, ex rel. Mees, v. Indus. Comm. (1972), 29 Ohio St. 2d 128. Where there is no evidence upon which the commission could have based its factual conclusion an abuse of discretion is present and mandamus becomes appropriate. State, ex rel. Hutton, v. Indus. Comm. (1972), 29 Ohio St. 2d 9.” State, ex rel. Kramer, v. Indus. Comm. (1979), 59 Ohio St. 2d 39, 42.
In essence, relator-appellant argues that the commission abused its discretion in denying her claim for permanent and total disability in that there was no evidence before the commission that she was not so disabled.
This court agrees with appellant that the report of Dr. Kessler constitutes evidence that the claimant is permanently and totally disabled since it complied with the requirements set forth in State, ex rel Anderson, v. Indus. Comm. (1980), 62 Ohio St. 2d 166, that where a claimant’s application for permanent and total disability compensation is based on two or more conditions which have been allowed by the commission, medical testimony must take into account the combined effects of these conditions in determining disability.1 We further *168agree with appellant that, based on State, ex rel. Anderson, v. Indus. Comm., the medical report of Dr. McCloud cannot constitute evidence to support the commission’s finding that appellant is not permanently and totally disabled, for the report failed to consider her psychological condition which had been previously allowed by the commission.2
The reports of both psychiatrists likewise cannot, by themselves, be considered evidence upon which the commission could base its final orders. Neither Dr. Giray nor Dr. Horwitz examined appellant as to her elbow and back injuries, and hence were non-examining physicians as to those injuries. (See State, ex rel. Wallace, v. Indus. Comm. [1979], 57 Ohio St. 2d 55.) This court’s holding in State, ex rel. Wallace, v. Indus. Comm. requires a non-examining physician to expressly adopt the factual findings of all examining physicians which appear in the record as the basis of his opinion. Since neither report expressly adopted the factual findings of those who actually examined appellant, they cannot constitute evidence upon which the commission may rely.
While the evidence in the reports of Drs. McCloud, Horwitz and Giray is insufficient in itself to support or deny a claim for permanent and total disability, it is nonetheless relevant and admissible. In Fox v. Indus. Comm. (1955), 162 Ohio St. 569, 577, this court held that “* * * evidence is relevant and admissible if it tends to prove a certain element of an ultimate fact even though it does not tend to establish all elements of the ultimate fact necessary to be proved; and evidence is relevant and admissible if it tends to corroborate evidence of certain but not all elements of a necessary ultimate fact. * * * ”
Thus, the Court of Appeals did not err in finding that the commission could use the factual findings contained in these reports to test the credibility and reliability of the report of Dr. Kessler, the only report herein that complied with the tests set forth in State, ex rel. Anderson, v. Indus. Comm. and State, ex *169rel. Wallace, v. Indus. Comm., supra, that appellant was permanently and totally disabled. The determination of disputed factual situations is clearly within the jurisdiction of the commission (State, ex rel. General Motors Corp., v. Indus. Comm. [1975], 42 Ohio St. 2d 278, 282-283), and since there was a conflict in the objective findings of the two orthopedic specialists,3 the commission had reason either to doubt the validity of Dr. Kessler’s findings or to conclude that appellant’s condition had improved since the time of examination. “ ‘***[W]here the record contains some evidence to support the commission’s factual findings, these findings will not be disturbed. State, ex rel. General Motors Corp., v. Indus. Comm. (1975), 42 Ohio St. 2d 278, 283; State, ex rel. Capital City Excavating Co., v. Indus. Comm. (1978), 54 Ohio St. 2d 184, 188-189.’ ” State, ex rel. Dodson, v. Indus. Comm. (1980), 62 Ohio St. 2d 408, 410.
The holdings in State, ex rel. Anderson, v. Indus. Comm. and State, ex rel. Wallace, v. Indus. Comm., supra, do not require the commission to accept the factual findings stated in a properly qualified medical report at face value and unquestioningly adopt them as those of the commission. To do so would be tantamount to allowing a physician to determine disability rather than the commission. Questions of credibility and the weight to be given evidence are clearly within the commission’s discretionary powers of fact finding. See, generally, State, ex rel. Shelton, v. Indus. Comm. (1929), 121 Ohio St. 41; State, ex rel. Ohio Bell Telephone Co., v. Krise (1975), 42 Ohio St. 2d 247.
Since appellant failed to establish a clear legal right to a writ of mandamus compelling the commission to grant her permanent and total disability, the judgment of the Court of Appeals is affirmed.
Judgment affirmed.
*170Celebrezze, C. J., W. Brown, Sweeney, Locher, Holmes and Krupansky, JJ., concur.Dr. Kessler found permanent and total disability based solely on the basis of relator’s combined physical injuries. Dr. Kessler’s failure to consider relator’s *168psychological condition in no way negates his findings, for his report pre-dated the allowance of that condition and he found the two physical injuries sufficient to render relator permanently and totally disabled. Furthermore, this court held in State, ex rel. Anderson, v. Indus. Comm. (1980), 62 Ohio St. 2d 166, at page 168, that “* * *it may not always be necessary that the physicians evaluate every condition allowed in a claim***.”
Dr. McCloud confined his report solely to relator’s back and elbow injuries.
The Court of Appeals noted the conflict in objective factual findings of the two orthopedic specialists to be as follows:
“Dr. Kessler found limitation of motion in relator’s right elbow and forearm; Dr. McCloud found elbow and forearm motion to be normal. While Dr. Kessler found relator’s side bending to be possible only to 15 degrees, Dr. McCloud found right-and-left-side bending normal. Again, Dr. Kessler found tightness in relator’s low back, whereas Dr. McCloud observed good flexibility.”