United States District Court, N.D. California
FINAL PRETRIAL ORDER
PHYLLIS J. HAMILTON UNITED STATES DISTRICT JUDGE
to Rule 16(e) of the Federal Rules of Civil Procedure, this
final pretrial order is hereby entered and shall control the
course of the trial unless modified by a subsequent order.
Plaintiff's Daubert Motion
witness who has been qualified as an expert by knowledge,
skill, experience, training, or education may give an opinion
on scientific, technical, or otherwise specialized topics if
(1) the expert's scientific, technical, or other
specialized knowledge will help the trier of fact to
understand the evidence or to determine a fact in issue, (2)
the testimony is based on sufficient facts or data, (3) the
testimony is the product of reliable principles and methods;
and (4) the witness has reliably applied the principles and
methods to the facts of the case. Fed.R.Evid. 702; see
also Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579
proponent of expert testimony bears the burden of
establishing by a preponderance of the evidence that the
admissibility requirements are met. See Fed. R.
702, Advisory Committee Notes. Although relevant evidence
enjoys the presumption of admissibility, the trial court is
obliged to act in a “gatekeeping role” with
regard to the admission of expert scientific testimony under
Rule 702. Daubert, 509 U.S. at 597; see also
Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 147
(1999). “This entails a preliminary assessment of
whether the reasoning or methodology underlying the testimony
is scientifically valid and of whether that reasoning or
methodology properly can be applied to the facts in
issue.” Daubert, 509 U.S. at 592-93.
Daubert requires a two-part analysis. Id.
The court first determines whether an expert's testimony
reflects “scientific knowledge, ” whether the
findings are “derived by the scientific method, ”
and whether the work product is “good
science”-that is, whether the testimony is reliable and
trustworthy. Daubert, 509 U.S. at 590 & n.9,
593. The court then determines whether the testimony is
“relevant to the task at hand.” Id. at
evidence is reliable if it is grounded in methods of
science-the focus is on principles and methodology, not on
conclusions. Metabolife Int'l, Inc. v. Wornick,
264 F.3d 832, 841 (9th Cir. 2001). In determining whether an
expert's reasoning or methodology is scientifically
valid, the district court can consider “many
factors” including (1) whether a scientific theory or
technique can be (and has been) tested; (2) whether the
theory or technique has been subjected to peer review and
publication; (3) whether there is a known or potential error
rate; and (4) whether the theory or technique is generally
accepted in the relevant scientific community. See
Metabolife, 264 F.3d at 841; Daubert, 509 U.S.
depending on the type of expert testimony offered, these
factors may not be appropriate to assess reliability.
Kumho Tire, 526 U.S. at 150. Other factors that
might be considered to assess reliability include whether an
expert has unjustifiably extrapolated from an accepted
premise to an unfounded conclusion, or whether an expert has
adequately accounted for obvious alternative explanations.
See General Elec. Co. v. Joiner, 522 U.S. 136, 146
(1997) (“[N]othing in either Daubert or the
Federal Rules of Evidence requires a district court to admit
opinion evidence that is connected to existing data only by
the ipse dixit of the expert. A court may conclude that there
is simply too great an analytical gap between the data and
the opinion proffered.”); Claar v. Burlington
Northern R. Co., 29 F.3d 499, 502 (9th Cir. 1994). In
addition, the trial court should ensure the expert
“employs in the courtroom the same level of
intellectual rigor that characterizes the practice of an
expert in the relevant field.” Kumho Tire, 526
U.S. at 152.
702's second prong concerns relevancy, or
“fit.” See Daubert, 509 U.S. at 591.
Expert opinion testimony is relevant if the knowledge
underlying it has a “valid scientific connection to the
pertinent inquiry.” Id. at 591-92. As Rule 702
requires, it must “assist the trier of fact to
understand the evidence or to determine a fact in
issue.” Id. at 590-92. But “scientific
validity [and relevance] for one purpose is not necessarily
scientific validity for other, unrelated purposes.”
Id. at 591.
party disputes Ravani's qualifications in the field of
biomechanics. Defendant argues that only a medical doctor can
qualify to offer an opinion about injury causation. Although
some courts have held otherwise, the weight of authority
supports the conclusion that “the fact that a
biomechanical expert is not a medical doctor does not mean
that he is not qualified to offer an opinion as to specific
causation.” Allen v. State Farm Mut. Auto. Ins.
Co., No. 3:15-CV-0019-HRH, 2016 WL 9086966, at *4 (D.
Alaska Aug. 2, 2016) (collecting cases); see also
Yu-Santos v. Ford Motor Co., No. 1:06CV01773AWI-DLB,
2009 WL 1392085, at *13 (E.D. Cal. May 14, 2009); Ream v.
United States, No. 2:17-CV-1141-RAJ, 2019 WL 2578600, at
*2 (W.D. Wash. June 24, 2019).
argues that Ravani's opinions are not the product of
reliable principles and methods, and that he has not reliably
applied the principles and methods to the facts of the case.
See Fed.R.Evid. 702; see also Daubert, 509
U.S. at 579. Specifically, plaintiff primarily challenges
Ravani's opinions that “[t]ypically, a value of
1000 HIC is determined to be the threshold for a head injury.
For mild TBI, HIC values as low as 400 in one study  and
160 in another study  are considered as the beginning
levels for such injuries.”; and “[t]he lowest
peak G-forces or linear acceleration to be consistent with
TBI are reported to be 60g's or higher. In this incident
even the upper limit values . . . are far below what has been
observed to be consistent with TBI.”; and “there
is no reasonable probability that the forces and motions
imparted to Ms. Hudson's head in the subject incident to
[sic] have any potential for brain injuries.” Dkt. 38-1
at ECF pp. 21-22. For the following reasons, those opinions
court finds that the evidence before it does not show that
these opinions are the product of reliable principles and
methods, or that Ravani has reliably applied the principles
and methods to the facts of the case. Although Ravani
reliably calculates the various forces that a bag of a
certain weight would impose on an individual when falling
from a certain height, there is no indication that Ravani has
applied a generally-accepted, peer-reviewed, scientific
theory or technique with a known error rate for determining
whether such a force can cause mTBI. The studies Ravani cites
in his report in fact suggest that no such generally-accepted
standard establishing a force threshold for mTBI exists.
Furthermore, even if defendant had demonstrated that Ravani
relied upon sound principles and methods, the court finds
that Ravani did not reliably apply the principles and methods
to the facts of the case, because the report did not
incorporate plaintiff's particular characteristics (for
example, her age or physical condition) when assessing the
minimum threshold of force that could have caused mTBI.
other objections to Ravani's testimony are denied. In
particular, Ravani's calculations based on exemplar
physical models are permissible so long as a foundation for
those measurements is entered into evidence. Of course,
plaintiff may cross-examine Ravani in an attempt to elucidate
the proper weight the jury should afford his testimony given
its factual underpinnings.
Plaintiff's Motions in Limine
Plaintiff's Motion in Limine No. 1
Plaintiff's first motion in limine to preclude defendant
from introducing expert testimony not disclosed in its expert
disclosures is DENIED. Plaintiff has not specified any
particular evidence she seeks to exclude, but rather refers
to unbounded, broad categories of evidence. Although the
opinions experts testify to must be limited to the contents