concurring in part and dissenting in part:
I concur in my colleagues’ conclusion that the district court properly submitted the issue of causation of Lewis’ knee injuries to the jury, but do not agree that the district court erred by similarly allowing the jury to decide the question of causation with respect to the wrist injury. The standard of review for the district court’s denial of a judgment as a matter of law is narrow, and the challenging party bears an “extremely heavy” burden. Ferebee v. Chevron Chem. Co., 736 F.2d 1529, 1534 (D.C.Cir.) (quotations and citations omitted), cert. denied, 469 U.S. 1062, 105 S.Ct. 545, 83 L.Ed.2d 432 (1984). We review the denial de novo, asking whether, viewing the evidence in the light most favorable to Lewis, and giving her every reasonable inference, the evidence is so one-sided that no reasonable juror could find that the brake failure caused her wrist injury. See Ealy v. Richardson-Merrell, Inc., 897 F.2d 1159, 1161 (D.C.Cir.), cert. denied, 498 U.S. 950, 111 S.Ct. 370, 112 L.Ed.2d 332 (1990); see also McNeal v. Hi-Lo Powered Scaffolding, Inc., 836 F.2d 637, 64-41 (D.C.Cir.1988).
I do not believe that WMATA came close to meeting that heavy burden. There was ample expert evidence to show that Lewis suffered a wrist injury. She complained of swelling and discomfort in her arm, beginning the week after the accident, and continuing for over two years until Dr. Cowen finally performed surgery. While it appears from the record that Lewis did not specifically mention pain in her wrist until her first visit to Dr. Cowen approximately two years after the accident, the jury could have found that the arm pain radiated from the wrist injury, or even that Lewis’ references to her arm included her wrist. The surgery performed by Dr. Cowen revealed synovitis and some cartilage damage, which he attributed to an earlier ligament tear. Dr. Cowen described the synovitis as a “swelling of these little linings of the joint” which is comparable to the phenomenon that once you have bitten the inside of your cheek, it is easier to bite it again. Dr. Cowen further explained that the cartilage damage probably resulted from bones rubbing against each other, and compared the damage to having a pebble in your shoe that “becomes an irritant.” In sum, Dr. *682Cowen’s testimony indicates that the symptoms of which Lewis complained after the accident, i.e., long-term swelling and discomfort, are those traditionally associated with synovitis and cartilage damage. It is true that defendant’s expert witness testified that a ligament tear would have caused immediate pain in the specific wrist area, but the jury was entitled either to disregard that testimony if it chose, or to infer that the swelling and pain she suffered within a week after the fall came from a cause other than a ligament tear.
Because the cause of the wrist injury relates “to matters of common experience, knowledge, or observation of laymen,” Jones v. Miller, 290 A.2d 587, 590-91 (D.C.1972) (citations and quotations omitted), Lewis was not required to provide expert testimony on causation. The nexus between breaking a fall with one’s hand and an injury resulting from a combination of swelling and bones rubbing together is something that a layperson can analyze without expert testimony, even if the injury was not properly diagnosed until over two years after the accident; there is no time limit to the “common knowledge” exception to the expert testimony requirement. Cf. Majority Opinion at 681, n. 5. Lewis should not be penalized for the failure of her initial treating physician, Dr. Goltz, to diagnose the synovitis and the cartilage damage, whatever its underlying origins. Starting from the day of the accident, Lewis consistently reported discomfort in her right arm, which alternately took the form of heaviness, swelling, pain, and tenderness. Moreover, this is the type of medically simple case for which the Jones exceptions were designed — Lewis did not have a complicated prior medical history, and there is no evidence to contradict her testimony that she sustained no injury whatsoever to her right arm or wrist either before or after the fall on the bus. See Jones, 290 A.2d at 590 (noting that on “many occasions” simple medical questions excuse need for expert testimony); cf. Baltimore v. B.F. Goodrich Co., 545 A.2d 1228 (D.C.1988) (requiring expert testimony due to complex nature of disability — anxiety and depression — and multiple preexisting and concurrent possible causes); Early v. Wagner, 891 A.2d 252 (D.C.1978) (requiring expert testimony due to plaintiff’s complicated and lengthy medical history and her cerebral thrombosis). Thus there is sufficient evidence from which a reasonable juror could have concluded that the sudden stop of the bus, which threw Lewis out of her seat and caused her to land on her right hand and wrist, caused the subsequent synovitis and cartilage damage. I would therefore uphold the reduced jury award of $300,000.