The opinion of the court was delivered by: HARRIS
STANLEY S. HARRIS, United States District Judge
The relevant legal doctrine is well-established. In seeking disability benefits under 42 U.S.C. § 423, Cowan, the claimant, bears the initial burden of showing, by a preponderance of the evidence, that she is "disabled," such that she is incapable of performing her prior work. Martonik v. Heckler, 773 F.2d 236, 239 (8th Cir. 1985); Hall v. Harris, 658 F.2d 260, 264 (4th Cir. 1981), see 42 U.S.C. § 423(a)(1)(D). In making this determination, four types of information are relevant: (1) objective medical data and findings; (2) expert opinions of treating and examining physicians; (3) subjective complaints of pain; and (4) the individual's age, education, and work history. Owens v. Heckler, 770 F.2d 1276, 1279 (5th Cir. 1985); Davis v. Heckler, 566 F. Supp. 1193, 1196 (D.D.C. 1983); see 42 U.S.C. § 423(d). Additionally, Cowan must demonstrate that she became disabled during the time period, as determined under 42 U.S.C. § 423(c)(1), in which her earnings history conferred "insured status." Owens, 770 F.2d at 1280; Garner v. Heckler, 745 F.2d 383, 390 (6th Cir. 1984); see 42 U.S.C. § 423(a)(1)(A).
If Cowan meets her burden of persuasion, the burden shifts to the Secretary to demonstrate that despite her inability to perform her previous job, Cowan's "residual functional capacity" enables her to perform other substantial, gainful activity. Martonik, 773 F.2d at 239-40; Hall, 658 F.2d at 264-65. At the administrative level, this determination is made by referring to general rules and tables, known as "grids," which allow the Administrative Law Judge (ALJ) to interrelate the claimant's functional capacity, age, educational and work experience, and conditions in the national job market. Hall, 658 F.2d at 265; see 20 C.F.R. §§ 404.1504-13 & App. 2.
In reviewing the Secretary's decision, the Court may not reverse if the Secretary's findings are supported by "substantial evidence." 42 U.S.C. § 405(g). The Supreme Court has defined substantial evidence as "more than a mere scintilla. It means such relevant evidence as a reasonable mind might accept as adequate to support a conclusion." Richardson v. Perales, 402 U.S. 389, 401, 28 L. Ed. 2d 842, 91 S. Ct. 1420 (1971). Accordingly, the Court does not engage in de novo review of the facts, and does not substitute its judgment concerning the weight and validity of the evidence for the Secretary's. Reading v. Mathews, 542 F.2d 993, 997 (7th Cir. 1976); Davis, 566 F. Supp. at 1195.
B. The Administrative Record
The plaintiff, Mary Cowan, was born on November 19, 1926, (R. 56) and completed 11th grade before leaving school (R. 23). From 1959 to 1977, Cowan worked as a coffee maker for a caterer (R. 23-24). After that, from April to October of 1979, Cowan worked as a cashier in the cafeteria for a Navy research center. In addition to her duties as a cashier, she was responsible for meat slicing, and salad, sandwich, and coffee preparation (R. 23-27). She has not worked since October 1979 (R. 28).
Cowan's medical difficulties of record began in 1978, when she visited Dr. Jeffrey D. Sabloff, an orthopedic surgeon, for treatment of a sore left shoulder (R. 97). X-rays revealed a calcium deposit in the biceps tendon (R. 97). Dr. Sabloff placed the arm in a sling, and prescribed medication and heat treatments (R. 97). By July of 1978, Cowan was asymptomatic with "excellent motion of her shoulder," and she was off all medication (R. 97). Residual pain in the shoulder was noted in office visits during August and September of 1978, but is not mentioned after September 27, 1978 (R. 100-01). In September of 1978, Cowan began to notice pain in her left knee, which Dr. Sabloff diagnosed as degenerative arthritis (R. 101). He prescribed anti-inflammatory medication and heat, and injected the knee with Xylocaine and Depo Medrol (R. 101).
According to Dr. Sabloff's notes, Cowan "was well until August 22 [1979,] when she hit her leg against a electrical outlet at work." (R. 102.) Apparently, while Cowan operated the cash register at her cafeteria job, her ankle repeatedly struck a protruding floor outlet near the cash register (R. 27-28). When Dr. Sabloff examined her on March 10, 1980, he discovered some discoloration in her calf, and X-rays revealed degenerative arthritis in her ankle and evidence of what could have been an old fracture (R. 102). He noted that Cowan had full range of motion in the ankle, but experienced pain when flexing and extending the ankle (R. 102). Dr. Sabloff placed the ankle in a soft cast and prescribed medication (R. 102).
In May of 1980, Dr. Sabloff reported that the ankle had improved, and he removed the cast (R. 105). He noted minimal swelling and "a good, gentle" range of motion (R. 105). Dr. Sabloff prescribed physical therapy and anti-inflammatory medication (R. 105). The ankle made excellent progress between May and August 1980 (R. 106-07). Aside from occasional pain in her ankle and knee, Dr. Sabloff pronounced Cowan "essentially asymptomatic" and discharged her from active care on August 21, 1980 (R. 108). His notes indicate that Cowan was going back to work (R. 108).
In October 1980, Cowan returned to Dr. Sabloff complaining of intermittent pain in the ankle (R. 109). X-rays revealed further degenerative changes in the ankle and contact between the two bones in the ankle, which Dr. Sabloff identified as the source of the pain (R. 109). He resumed anti-inflammatory medication, and directed Cowan to resume wearing her ankle brace (R. 109). He also informed Cowan that it was important that she lose weight to relieve pressure on her ankle (R. 109). The ankle improved during November and December of 1980, and on December 9, 1980 (R. 110-11), Dr. Sabloff reported that Cowan was "doing well with minimal discomfort intermittently." (R. 111.) He also noted that palpation and gentle range of motion cause no pain, and that ...