On April 4, 1978, claimant was employed at Ideal of Idaho, a trailer manufacturing business, stapling rubber and plastic around cabinets. While lifting a cabinet she suffered an injury which was diagnosed as a back strain.
She consulted a chiropractor who referred her to a neurologist for evaluation and subsequent treatment. That doctor released the claimant to “light” work January 2, 1980. Claimant was compensated for total temporary disability until approximately September 1979, and she filed an application in March 1980 for a hearing before the Industrial Commission. A hearing was lield before a referee.
*33At that hearing the record indicates that in April 1981 claimant was employed as a hotel maid, working approximately 20 hours per week vacuuming, changing linen, and cleaning bathrooms. As of the hearing date claimant earned $3.35 per hour, the then minimum wage.
The referee also considered the deposition testimony of claimant’s treating neurologist, Dr. Curran, a psychologist and vocational expert, Dr. Bronson, an orthopedic surgeon, Dr. Taylor, a neurologist, Dr. Wilson, and the testimony of a field consultant with the Industrial Commission, Rehabilitation Division. Various medical reports were admitted into evidence.
The medical testimony was reasonably consistent to the effect that claimant suffers a permanent impairment of five percent of the whole person due to pain, which it was evidently assumed resulted from the industrial accident. However, Dr. Wilson, a neurologist, testified that the type of back injury suffered by claimant is self-healing, and that a myelogram, a CT scan, and EMG tests of the claimant were all negative. He also testified that the pain she was experiencing could well be due to emotional stress factors in her personality makeup. In general, the medical evidence indicated no anatomical cause for the pain suffered by claimant.
However, as to the extent of claimant’s permanent partial disability, the testimony was conflicting. Bronson, the psychologist, opined that claimant suffered from a 30 to 40 percent permanent partial disability. As indicated above, Wilson, the neurologist, indicated the injury was of the self-healing type and that all tests were negative. Jordon, the field consultant with the Industrial Commission, Rehabilitation Division, opined that claimant could return to the same type of work as she engaged in prior to the industrial accident, and that claimant suffered no reduction in her wage-earning capacity.
The referee found that “based on [claimant’s] continuing back pain, she has a permanent partial impairment equal to five percent of a whole person.” As to her permanent partial disability, the referee found as follows:
“IX
“At the time of her accident on April 4, 1978, the Claimant was forty-seven years old. She has an eighth grade education. Her work experience prior to the accident includes jobs in which she did finish work on trailers, made window frames, drove a pilot car during the moving of mobile homes, and did maid work at a motel. Based upon the record as a whole, considering the Claimant’s impairment and the nonmedical factors, including hut not limited to her age, education work experience, and training, the Claimant has not established that she suffered a permanent partial disability in excess of 5% of a whole person as a result of her accident of April 4, 1978.” (Emphasis added.)
The Industrial Commission adopted the referee’s findings of fact and conclusions of law, and entered its decision requesting permanent partial disability of only five percent of the whole person. This appeal is taken therefrom, with the claimant asserting either reconsideration by the Commission or a directed award for permanent partial disability of 30 to 40 percent of the whole person.
Our standard of review is well established. This Court is authorized to reverse a decision of the Commission only when the decision is unsupported by any substantial competent evidence or is not supportable as a matter of law. ID. CONST, art. 5, § 9; I.C. § 72-732. Appellate review of Commission decisions does not entail a de novo determination of fact. Graham v. Larry Donohoe Logging, 103 Idaho 824, 654 P.2d 1377 (1982). The weight to be accorded to evidence is within the province of the Commission. Nelson v. Pumnea, 106 Idaho 48, 675 P.2d 27 (1984).
The question presented is whether there is substantial competent evidence supporting the decision of the Commission that claimant’s permanent partial disability did *34not exceed a rating of five percent of the whole man, and thus that the disability rating did not exceed the impairment rating.
The burden of proof is upon the claimant to prove disability in excess of his impairment rating, although expert testimony on this issue need not be presented. Bennett v. Clark Hereford Ranch, 106 Idaho 438, 680 P.2d 539 (1984). The test for such determination is not whether the claimant is able to work at some employment, but rather whether the physical impairment, taken in conjunction with nonmedical factors, has reduced the claimant’s capacity for gainful activity. Id. In that determination, I.C. § 72-425 requires the Commission to take into consideration nonmedical factors such as age, sex, education, and economic and social environment.
The record indicates that the Commission considered the effect of the required nonmedical factors as bearing upon claimant’s ability to engage in gainful activity. Those factors were incorporated into the findings of fact. We further note that although not utilized by the Commission, a mathematical comparison of pre and post-injury wages is evidence of an injured worker’s ability to engage in gainful activity. Baldner v. Bennett’s, Inc., 103 Idaho 458, 649 P.2d 1214 (1982). Such a mathematical comparison is not in and of itself sufficient to satisfy the strictures of I.C. § 72-425. In the instant case, the testimony of the claimant indicated pre-injury she was earning $3.40 or $3.45 per hour, and post-injury was earning $3.35 per hour. Contrary to claimant’s assertion that the referee and Commission concluded the claimant had suffered no reduction in her wage-earning capacity, the Commission’s ruling rather is that claimant’s ability to engage in gainful activity has been reduced by five percent.
Claimant’s complaint of chronic back pain and inability to work beyond five hours per day were met with testimony that there was no anatomical cause for her pain, no physical evidence of injury, and that the large bulk of her complaints are independent of the effects of the injury and attributable to other factors.
We hold there is substantial competent evidence supporting the decision of the Commission. We have considered claimant’s other assertions of error and find them to be without merit. The decision of the Commission is affirmed.
Costs to respondents.
No attorney fees on appeal.
DONALDSON, C.J., and BAKES, J. concur.