                                                                          F I L E D
                                                                    United States Court of Appeals
                                                                            Tenth Circuit
                       UNITED STATES COURT OF APPEALS
                                                                            SEP 5 2002
                              FOR THE TENTH CIRCUIT
                                                                       PATRICK FISHER
                                                                                Clerk

    RAE BROWN,

                  Plaintiff-Appellant,

    v.                                                    No. 01-5220
                                                    (D.C. No. 00-CV-912-M)
    JO ANNE B. BARNHART,                                  (N.D. Okla.)
    Commissioner, Social Security
    Administration,

                  Defendant-Appellee.


                              ORDER AND JUDGMENT          *




Before HENRY , ANDERSON , and HARTZ , Circuit Judges.




         After examining the briefs and appellate record, this panel has determined

unanimously that oral argument would not materially assist the determination

of this appeal.    See Fed. R. App. P. 34(a)(2); 10th Cir. R. 34.1(G). The case is

therefore ordered submitted without oral argument.




*
      This order and judgment is not binding precedent, except under the
doctrines of law of the case, res judicata, and collateral estoppel. The court
generally disfavors the citation of orders and judgments; nevertheless, an order
and judgment may be cited under the terms and conditions of 10th Cir. R. 36.3.
      Plaintiff Rae Brown appeals from an order of the district court   affirming

the Commissioner’s determination that she is not entitled to Social Security

disability benefits. Because the Commissioner’s determination is supported by

substantial evidence in the record, we affirm.


                                           I.

      We review the Commissioner’s decision to determine whether her factual

findings were supported by substantial evidence in light of the entire record and

to determine whether she applied the correct legal standards. See Castellano v.

Sec’y of Health & Human Servs., 26 F.3d 1027, 1028 (10th Cir. 1994).

“Substantial evidence is such relevant evidence as a reasonable mind might accept

as adequate to support a conclusion.” Id. (quotations omitted). In the course of

our review, we may “neither reweigh the evidence nor substitute our judgment for

that of the agency.” Casias v. Sec’y of Health & Human Servs., 933 F.2d 799,

800 (10th Cir. 1991).


                                           II.

      Ms. Brown alleged disability as of October 28, 1994, 1 due to emphysema,

heart disease, hypertension, muscle spasms in the back, blocked arteries, and


1
      Ms. Brown’s insured status expired December 31, 1995 , thus she must
show she was totally disabled prior to that date. See Henrie v. United States
Dep’t of Health & Human Servs. , 13 F.3d 359, 360 (10th Cir. 1993).

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umbilical hernia. She stated that her primary problem was extreme fatigue. The

administrative law judge (ALJ) determined that Ms. Brown was not disabled at

step four of the five-step sequential process, see Williams v. Bowen, 844 F.2d

748, 750-52 (10th Cir. 1988), as she could return to her past relevant work .


                                         III.

A.    Medical Evidence of Residual Functional Ability

      On appeal, Ms. Brown first argues that t   he ALJ’s assessment of her

residual functional ability is not supported by substantial evidence. To support

this argument, Ms. Brown submits her analysis of two medical studies regarding

the measurement of energy expenditures as expressed in METs. Ms. Brown

compares the METs required for various activities as set forth in the articles with

her estimate of the maximum METs she can expend based on the results of her

treadmill tests. She concludes that the work the ALJ determined she can perform

requires greater METs than she can expend.

      We decline to use this analysis to determine whether Ms. Brown is

disabled. The determination of disability rests on medical opinions. Medical

opinions are “statements from physicians and psychologists or other acceptable

medical sources that reflect judgments about the nature and severity of your

impairment(s), including your symptoms, diagnosis and prognosis, what you

can still do despite impairment(s), and your physical or mental restrictions.”

                                         -3-
20 C.F.R. § 404.1527(a)(2). Acceptable medical sources are defined at

§ 404.1513(a). Medical journal articles are not included as acceptable medical

sources. We cannot give persuasive authority to an attorney’s extrapolation of

a medical article to his client’s condition. See , e.g., Soc. Sec. Rul. 96-5p,

1996 WL 374183, at *4 (clarifying that medical source statements must be

submitted by acceptable medical sources and are to be based on the medical

sources’ personal knowledge of the claimant). While medical literature can be

cited and relied on to support a claimant’s position, it cannot be the only

evidence showing disability.

      The record shows that none of Ms. Brown’s treating physicians has

considered her disabled or unable to perform substantial gainful activity.

Admittedly, her treadmill tests had to be ended prematurely due to her dyspnea

and leg fatigue. However, she experienced no chest pain during the test and the

results were still determined to not be significant. See App. Vol. II at 129-30;

Vol. III at 140, 150. While Ms. Brown is overweight and her smoking

contributes to her cardiac and lung problems, these impairments cannot be

considered disabling. Ms. Brown notes that none of her treating physicians has

stated that she is able to work. However, Ms. Brown bears the burden of proving

disability through step four; the Commissioner need not show she is able to work

until step five. See Ray v. Bowen , 865 F.2d 222, 224 (10th Cir. 19 89).


                                          -4-
B.    Credibility and Weight Loss

      Ms. Brown next argues that the ALJ did not properly evaluate her

credibility. She maintains that the ALJ cannot use her failure to lose weight as

a basis to judge her credibility without considering whether weight loss would

restore her ability to work, was prescribed, or was refused without justifiable

excuse, citing Thompson v. Sullivan , 987 F.2d 1482, 1490 (10th Cir. 1993)      .

While Ms. Brown correctly cites to   Thompson , the ALJ did not erroneously

consider her weight. The ALJ, in addition to noting her physician’s comments

that she appeared to be uninterested in changing her behavior regarding her diet

and smoking, also considered

      claimant’s own description of her activities and life style, the degree
      of medical treatment required, discrepancies between the claimant’s
      assertions and information contained in the documentary reports, the
      claimant’s demeanor at hearing, the reports  of the treating and
      examining practitioners, the medical history, the findings made on
      examination, and the claimant’s assertions concerning her ability to
      work.

App. Vol. II at 19.

      The ALJ adequately supported his credibility determination as he

then discussed each item he identified. Further, the record supports the ALJ’s

findings.




                                         -5-
                                        IV.

      Substantial evidence in the record supports the ALJ’s determination

that Ms. Brown could return to her prior work as a sewing machine operator or

a cashier. Therefore, the judgment of the United States District Court for the

Northern District of Oklahoma is AFFIRMED.


                                                   Entered for the Court



                                                   Robert H. Henry
                                                   Circuit Judge




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