The opinion of the court was delivered by: Stephen J. Hillman United States Magistrate Judge
MEMORANDUM DECISION AND ORDER
This matter is before the Court for review of the Social Security Commissioner's decision denying Plaintiff's application for Disability Insurance Benefits and Supplemental Security Income under Titles II and XVI of the Social Security Act. Pursuant to 27 U.S.C. § 636(c), the parties have consented that the undersigned may handle the case. The action arises under 42 U.S.C. § 405(g), which authorizes the Court to enter judgment upon the pleadings and transcript of the record before the Commissioner. Plaintiff and Defendant have filed their pleadings (Plaintiff's Memorandum of Points and Authorities in Support of Plaintiff's Complaint and Defendant's Memorandum of Points and Authorities in Opposition to Plaintiff's Complaint), and Defendant has filed the certified transcript of record. After reviewing the matter, the Court concludes that the Commissioner's decision should be affirmed.
Plaintiff Esperanza De Rivera ("Plaintiff") applied for Supplemental Security Income ("SSI") on December 18, 2006 and Disability Insurance Benefits ("DIB") on January 23, 2007, alleging inability to work since March 14, 2004. (AR 65-76, 80-104).*fn1 An administrative hearing was held on February 22, 2008. (AR 10-25). On April 3, 2008, an Administrative Law Judge ("ALJ") determined that Plaintiff was not disabled within the meaning under the Social Security Act. (AR 28-36). Following the Appeals Council's denial of Plaintiff's request for a review of the hearing decision, Plaintiff filed an action in this Court. (AR 1-4).
Plaintiff challenges the ALJ's decision on the sole grounds that the ALJ erred at step four of the five-step sequential evaluation process by (1) insufficiently ascertaining the demands of Plaintiff's past relevant work and (2) improperly finding that Plaintiff could return to her past relevant work as a assembly line worker and housekeeper as actually performed. For the reasons discussed below, the Court concludes that the Commissioner's decision should be affirmed.
The Social Security Regulations have established a five-step sequential evaluation process for determining whether a claimant is disabled. See SSR 82-62; 20 C.F.R. § 404.1520; see also Hoopai v. Astrue, 499 F.3d 1071, 1074 (9th Cir. 2007). During step four, a claimant's Residual Functional Capacity ("RFC") assessment is compared with the physical and mental demands of the claimant's past relevant work to determine if the claimant is capable of performing her past work. See SSR 82-62; 20 C.F.R. §§ 404.1520(f), 416.920(f), 404.1560(b), 416.960(b). If the claimant's RFC enables her to perform past relevant work, either as actually or generally performed, the claimant will not be found to be disabled. Id. at §§ 404.1520(f), 416.920(f); see also SSR 82-61; Pinto v. Massanari, 249 F.3d 840, 844-45 (9th Cir. 2001).
In defining a claimant's past relevant work as actually performed, two informational sources may be used: (1) a properly completed vocational report, SSR 82-61; and (2) the claimant's own testimony. See Pinto, 249 F.3d at 845; SSR 82-62 ("The claimant is the primary source for vocational documentation, and statements by the claimant regarding past work are generally sufficient for determining [the demands of past relevant work].").
Moreover, "[a]t step four, claimants have the burden of showing that they can no longer perform their past relevant work." Id. at 844 (citing C.F.R. §§ 404.1520(f), 416.920(f)). An ALJ, however, "still has a duty to make the requisite factual findings to support his conclusion . . . by looking at the residual functional capacity and the physical and mental demands of the claimant's past relevant work." Id. at 844-45; see also Villa v. Heckler, 797 F.2d 794, 797-98 (9th Cir. 1986) ("To determine whether a claimant has the residual capacity [RFC] to perform his past relevant work, the Secretary must ascertain the demands of the claimant's former work and then compare the demands with his present capacity [RFC].").
As to Plaintiff's first claim of error, the Court finds that the ALJ sufficiently ascertained the demands of Plaintiff's past work. The ALJ in this case instructed Dr. Ron Hatakeyama, a vocational expert, to ask Plaintiff questions to determine whether she had done any past work at a "light" RFC.*fn2 (AR 14). Dr. Hatakeyama asked Plaintiff a series of questions concerning four of the jobs Plaintiff had previously identified, two of which were jobs as an assembly line worker and a housekeeper. (AR 14-15). Dr. Hatakeyama asked Plaintiff to describe what she did as an assembly line worker and to "include the physical demands." (AR 14). Dr. Hatakeyama also asked Plaintiff whether she stood "most of the day" and to estimate how many pounds she had to lift. (AR 15). With respect to Plaintiff's past work as a housekeeper, Dr. Hatakeyama asked Plaintiff whether she worked in a hotel or a home, whether she had to push a cart, and how much she had to lift. (AR 15-16).
In responding to Dr. Hatakeyama's questions, Plaintiff testified with an English/Spanish interpreter's assistance due to her illiteracy in English. Plaintiff specifically testified that the physical demands of her job as an assembly line worker did not require heavy lifting as she would lift approximately ten pounds. (AR 14-15). She also testified that she was required to put lids on little bottles, such as nail polish bottles and lipstick. (AR 14-15). With respect to her past work as a housekeeper, Plaintiff testified that she worked in both hotels and homes, and would not lift anything heavy. (AR 15-16). She testified that she was required to push a cart and "[j]ust make the beds . . . deal with the towels. Nothing heavy." (AR 16). In addition, Plaintiff testified that she was able to perform her past jobs as an assembly line worker and housekeeper, as actually performed, despite her inability to speak English. (AR 18-19).
In light of Dr. Hatakeyama's line of questioning and Plaintiff's testimony, the Court finds that the ALJ sufficiently ascertained the demands of Plaintiff's past work. The ALJ instructed Dr. Hatakeyama to ask Plaintiff specific questions concerning the physical demands of her past work. (AR 14-18). In response, Plaintiff described the physical demands of her past work as an assembly line worker and housekeeper as she actually performed them. (AR 14-16). Plaintiff's description about the demands of her past work as she actually performed them, gave the ALJ sufficient information to compare those demands with the Plaintiff's "light" RFC to determine whether she could return to her past work as actually performed.*fn3 See Pinto v. Massanari, 249 F.3d 840, 845 (9th Cir. 2001); see also SSR 82-62 ("The claimant is the primary source for vocational documentation, and statements by the claimant regarding past work are generally sufficient for determining [the demands of past relevant work].").
In addition, not only did the ALJ solicit testimony from the Plaintiff concerning the demands of her past work, but the ALJ produced useful vocational evidence to ascertain the demands of Plaintiff's past work, despite not being required to do so. Specifically, since the Court finds that Plaintiff had not satisfied her burden at step four of the five-step sequential evaluation process in showing that she was unable to perform her past work as actually performed (see discussion, infra), the ALJ was not required to produce vocational expert testimony. See Matthews v. Shalala, 10 F.3d 678, 681 (9th Cir. 1993) (explaining that since the plaintiff failed to meet her burden at step four, "vocational expert testimony was  useful, but not required"); see also Miller v. Heckler, 770 F.2d 845, 850 (9th Cir. 1985) ("The Secretary is required to produce vocational evidence only when the claimant has shown that he or she cannot perform any previous relevant work."). The ALJ in this case, however, produced vocational expert testimony through Dr. Hatakeyama, who testified that Plaintiff could return to her past work as both a hotel housekeeper and assembly line worker as actually performed. (AR 19).
Accordingly, based on the foregoing circumstances, the Court concludes that the ALJ properly ascertained the demands of Plaintiff's past work as an assembly line worker and housekeeper.
With respect to Plaintiff's second claim of error, she challenges the ALJ's finding that she could perform her past work as an assembly line worker and housekeeper as she actually performed them.*fn4 As to Plaintiff's past work as an assembly line worker, Plaintiff asserts that the physical demands, as she actually performed them, required her to stand for eight hours during the workday. To support this proposition, Plaintiff solely relies on her testimony in which she said "only standing" when asked whether she stood "most of the day." (AR 15). Plaintiff therefore asserts that she can no longer perform her past work as an assembler as she actually performed it (i.e., stand for eight-hours), because her "light" RFC restricts her to standing or walking to no more than six hours in an eight-hour work day.
The Court, however, finds Plaintiff's interpretation of her testimony -- that she actually stood eight-hours during an eight-hour workday as an assembler --unconvincing. The more plausible interpretation, given the language barrier (illiteracy in English) and the specific question asked (whether she stood most of the day), is that Plaintiff meant that she would stand for most of the workday, as opposed to the entire workday. Under this interpretation, Plaintiff's description about the demands of her past work as an assembler would be consistent with the ALJ's "light" RFC finding, which requires standing or walking for most of an eight-hour workday (i.e., approximately six hours, taking into account lunch and other breaks). In fact, Dr. Hatakeyama's understanding of Plaintiff's testimony supports the Court's interpretation, as evidenced in the vocational interrogatory report he prepared, which noted that Plaintiff described the physical demands of an assembly line worker as she ...