United States Court of Appeals
                           FOR THE EIGHTH CIRCUIT

                                    ___________

                                    No. 98-1900
                                    ___________

Douglas R. Tenbarge, Lilly Tenbarge, *
                                     *
           Appellants,               *
                                     * Appeal from the United States
     v.                              * District Court for the
                                     * Eastern District of Missouri.
Ames Taping Tool Systems, Inc.,      *
                                     *
           Appellee.                 *
                                ___________

                              Submitted: November 18, 1998

                                   Filed: July 7, 1999
                                    ___________

Before McMILLIAN, WOLLMAN,1 and HANSEN, Circuit Judges.
                         ___________

WOLLMAN, Chief Judge.

       Douglas R. Tenbarge appeals from the district court’s order granting judgment
as a matter of law in favor of Ames Taping Tool Systems, Inc. (Ames) on Tenbarge’s
claim of failure to warn and from the judgment entered on a jury verdict against him on
his remaining claims. We reverse and remand for a new trial.



      1
        Roger L. Wollman became Chief Judge of the United States Court of Appeals
for the Eighth Circuit on April 24, 1999.
                                          I.

       From 1983 to 1993, Tenbarge worked as a drywall installer. His primary duty
was to apply drywall compound and tape along the seams of drywall panels with an
Ames Auto Taper, known as a Bazooka. The Bazooka is a tube fifty-six inches in
length and two and one-fourth inches in diameter used to apply joint compound and
tape simultaneously to drywall seams in ceilings and walls. It weighs seven pounds
when empty and twenty pounds when filled to capacity with joint compound and a 500-
foot roll of tape. The Bazooka is operated by holding it with both hands and applying
pressure against the seam as the joint compound and tape are being fed out of the tube.
As we recently noted in a case alleging claims of injuries somewhat similar to those
alleged by Tenbarge, the Bazooka requires repetitive wrist motions and the exertion of
considerable pressure to apply the tape and compound. Lacking handholds, “the
Bazooka is awkward to support and maneuver, particularly while doing overhead
work.” Bone v. Ames Taping Tool Sys., Inc., No. 98-2324, slip op. at 2 (8th Cir. June
8, 1999).

       In 1991, after experiencing numbness in his hands and fingers, Tenbarge
consulted a physician and was diagnosed with carpal tunnel syndrome (CTS). In
December 1992 and January 1993, Tenbarge underwent surgery on both wrists. He
returned to work in April 1993, only to sustain an elbow injury. He underwent a third
surgery late in 1993.

       Tenbarge filed suit in Missouri state court in 1994 against Ames, the
manufacturer and lessor of the Bazooka. He alleged cumulative injuries as a result of
using the Bazooka. In addition, his wife alleged loss of consortium. Ames removed
the case to federal court and was subsequently granted summary judgment. We
reversed the district court’s entry of summary judgment, finding that Tenbarge had
alleged sufficient facts to warrant jury consideration of the causation issue. See
Tenbarge v. Ames Taping Tool Sys., Inc., 

, 658 (8th Cir. 1997).

                                          -2-
      On remand, the district court granted judgment as a matter of law in favor of
Ames on Tenbarge’s claims of liability based upon Ames’s failure to warn of the
danger of injury resulting from the use of the Bazooka. The jury found in favor of
Ames on Tenbarge’s claims based upon negligence, strict liability for defective
condition, and breach of both express and implied warranties.

                                          II.

      During his deposition, Dr. Peter Nathan, one of Ames’s witnesses, testified that
“I don’t know what has caused [Tenbarge’s] carpal tunnel syndrome. I’ve listed -- or
given to you here what I would consider to be risks.” See Joint. Appx. at 000301.
There then followed this exchange between Tenbarge’s counsel and Dr. Nathan:

          Q. Can you say, Doctor, at this time within a reasonable degree of
      medical certainty what systemic disease or systemic problem, if any,
      Doug Tenbarge has which is contributing to this multiple entrapment
      phenomenon or abnormality?

           A. I cannot rule out alcohol because he does consume some --
      consume some alcohol and I don’t know at what point his threshold is
      met. I cannot rule out the rheumatoid because he does have a diagnosis
      of rheumatoid arthritis. . . .

           Q. You’re unable to rule out alcohol or rheumatoid arthritis, but are
      you, in any fashion, able to rule them in within a reasonable degree of
      medical certainty?

           A. I can only tell you that they have to be considered as risks.

           ....

          A. I’m not saying that the major cause or minor cause -- I can’t
      even tell you the major risk but they have -- they are certainly risks that


                                         -3-
      a physician in a workup must consider . . . in his differential diagnosis of
      risks.

Joint Appx. at 000304.

        At trial, Dr. Nathan’s testimony contrasted sharply with the foregoing deposition
testimony. Dr. Nathan stated that not only was rheumatoid arthritis a risk factor, but
that it was the major cause of Tenbarge’s CTS. The district court overruled Tenbarge’s
objections to this testimony, stating that any variation in Dr. Nathan’s testimony would
constitute excellent grounds for impeachment on cross examination. The district court
then denied Tenbarge’s request for leave to depose Dr. Nathan over the lunch hour.

      Tenbarge contends that he was prejudiced by this change in Dr. Nathan’s
testimony and that the district court abused its discretion in denying him leave to further
depose Dr. Nathan. In response, Ames contends that because Dr. Nathan repeatedly
characterized rheumatoid arthritis as a risk factor during his deposition, Tenbarge was
on notice that a significant portion of Dr. Nathan’s trial testimony would focus on
rheumatoid arthritis.

       Federal Rule of Civil Procedure 26(e) requires parties to supplement the
testimony of their expert witnesses to inform the opposing party of any changes or
alterations. If a party fails to supplement expert testimony, the district court may order
appropriate sanctions as provided for in Rule 37(c). Sanctions may include exclusion
of the testimony, a continuance to allow depositions to be taken, or the grant of a new
trial. The duty to supplement expert testimony extends to any changes or additions to
the information provided in a deposition. See 8 C. Wright, A. Miller, and R. Marcus,
Federal Practice and Procedure § 2049.1, at 605 (1994).

      “Discovery of expert opinion must not be allowed to degenerate into a game of
evasion.” Voegeli v. Lewis, 

, 97 (8th Cir. 1977). “[T]he purpose of our

                                           -4-
modern discovery procedure is to narrow the issues, to eliminate surprise, and to
achieve substantial justice.” Mawby v. United States, 

, 1254 (8th Cir.
1993) (quoting Greyhound Lines, Inc. v. Miller, 

, 143 (8th Cir. 1968)).

       Ames clearly had a duty to inform Tenbarge of any changes or additions in Dr.
Nathan’s testimony. Its failure to do so denied Tenbarge the opportunity to develop
his cross-examination of Dr. Nathan or to present additional expert witnesses to counter
Dr. Nathan’s newly arrived at conclusions. Because the cause of Tenbarge’s CTS was
a key issue at trial, see Bone, slip op. at 2-3, Tenbarge’s lack of opportunity to
challenge Dr. Nathan’s testimony on causation resulted in a fundamental unfairness that
requires us to order that he be granted a new trial. See Porchia v. Design Equip. Co.,

, 882 (8th Cir. 1997).

                                          III.

       The district court granted Ames’s motion for judgment as a matter of law on
Tenbarge’s strict liability and negligent failure to warn claims, ruling that Tenbarge
failed to present evidence of the Bazooka’s defect, what danger should have been
warned against, what an adequate warning should say, and that he would have heeded
a warning.

       When reviewing a grant of a motion for judgment as a matter of law, we assume
as true the evidence proffered by the nonmoving party, giving the non-moving party the
benefit of all inferences that could be reasonably drawn from the evidence. See
Toombs v. Bell, 

, 347 (8th Cir. 1990). We will take the issue from the
jury only if all the evidence supports the movant and the evidence is not susceptible of
any reasonable inferences that would support the position of the nonmoving party. See

is a diversity case, we review state law questions de novo. See Sperry
v. Bauermeister, Inc., 

, 597 (8th Cir. 1993).


                                          -5-
                                            A.

      In Missouri, there are five elements of a strict liability failure to warn claim: (1)
the defendant sold the product in the course of its business; (2) when used as
reasonably anticipated and without knowledge of its characteristics, the product was
unreasonably dangerous at the time of sale; (3) the defendant did not give an adequate
warning of the danger; (4) the product was used in a reasonably anticipated manner;
and (5) the plaintiff was damaged as a direct result of the product being sold without
an adequate warning. See Tune v. Synergy Gas Corp., 

, 13 (Mo. 1994)
(en banc).

       It is uncontested that Ames provided the Bazooka in the ordinary course of
business and that Tenbarge used the Bazooka in the manner for which it was intended.
Tenbarge introduced evidence sufficient to support an inference that the Bazooka was
unreasonably dangerous by presenting testimony concerning the risk of repetitive
trauma injury. The parties agree that Tenbarge was never given any warnings about the
use of the Bazooka during his job training. Bazookas shipped by Ames to Tenbarge’s
employer contained no accompanying literature instructing on their proper use nor any
warnings regarding the advisability of limiting their use. Ames admitted that from 1984
to 1995, it did not issue any warnings concerning the possibility of repetitive trauma or
repetitive stress injuries as a result of using the Bazooka.

        The central issue is whether Tenbarge made an adequate showing of causation.
To make a submissible case on causation, the plaintiff must show that the product
caused his injuries and that a warning would have altered his behavior. See Anderson
v. F.J. Little Mach. Co., 

, 1115 (8th Cir. 1995) (citing Arnold v. Ingersoll-
Rand Co., 

, 194 (Mo. 1992) (en banc)). Tenbarge’s treating physician,
Dr. Richard Chusak, testified that the Bazooka caused the onset of Tenbarge’s CTS,
testimony that we earlier found to be sufficient evidence of causation. See 

.

                                           -6-
       Under Missouri law, a rebuttable presumption that adequate warnings would
have been heeded arises if the plaintiff shows that no warning was given. See 

; Duke v. Gulf & Western Mfg. Co., 

, 419 (Mo. Ct.
App. 1983). The presumption should be recognized, however, only if there is a
“legitimate jury question whether the plaintiff did not already know the danger.” See

. “[A] preliminary inquiry before applying the presumption
is whether adequate information is available absent a warning.” See 

not told of any risks associated with using the Bazooka when he
first began using the tool. No analysis of ergonomic risk factors had been conducted
on the Bazooka; thus, no literature was available that could have informed Tenbarge
of the risks involved in using the Bazooka. Accordingly, because a jury could find that
he had no previous knowledge of any danger when he began using the Bazooka,
Tenbarge is entitled to the presumption that he would have altered his behavior had he
received an adequate warning. See 

.

       Ames contends that it produced sufficient evidence showing that Tenbarge would
not have heeded a warning had one been given. In 1992 and 1993, when Tenbarge
underwent surgery on both wrists, his physician told him that his CTS was caused by
the use of the Bazooka. Despite this information, Tenbarge returned to work following
the operations and used the Bazooka as before. This post-operative behavior, Ames
argues, indicates that Tenbarge would not have followed warnings had they been given.

       Although Tenbarge’s return to work following the surgeries is relevant to the
question whether he would have heeded warnings, we conclude that it is insufficient
to entitle Ames to judgment as a matter of law on this issue in light of the fact that
Tenbarge returned to work pursuant to his doctor’s instructions rather than in knowing
disregard of the health risks associated with using the Bazooka.




                                          -7-
                                            B.

       Tenbarge contends that the district court erred by refusing to instruct the jury on
his claim of negligent failure to warn. To establish such a claim, Tenbarge was
required to introduce evidence establishing the existence of the following elements: (1)
that Ames designed the Bazooka; (2) that Ames knew or had reason to know that the
Bazooka was likely to be unreasonably dangerous; (3) that Ames had no reason to
believe that the Bazooka’s users would realize the danger in using it; (4) that Ames
failed to use ordinary care in warning Tenbarge of the risk of harm; and (5) that the
failure to warn directly caused the injury. See Spuhl v. Shiley, Inc., 

,
578 (Mo. Ct. App. 1990). In addition, the product must malfunction or fail. See 

        It is uncontested that Ames designed the Bazooka and offered no warning
concerning its use. Tenbarge presented evidence through the testimony of Robert
Zdravecky, Ames’s president, that the company knew of the repetitive motion required
to use the Bazooka. Evidence that use of the Bazooka presented ergonomic risk factors
was sufficient to show defective condition. The risk of developing CTS by using the
Bazooka was not so open and obvious as to allow Ames to assume that users would
understand the danger in using it. Furthermore, Tenbarge made a prima facie showing
of causation, as discussed in the analysis of his claim of strict liability failure to warn.
Accordingly, the district court should have submitted Tenbarge’s negligent failure to
warn claim to the jury.

                                            IV.

      Tenbarge contends that the district court erred in limiting his cross examination
of Zdravecky. Having reviewed the record, we cannot say that the district court clearly
abused its discretion in so ruling. See Adams v. Fuqua Indus., Inc., 

, 273
(8th Cir. 1987).

                                            -8-
       In light of our holding, we need not address Tenbarge’s remaining allegation of
error. The judgment is reversed, and the case is remanded for a new trial.

      A true copy.

           Attest:

                CLERK, U.S. COURT OF APPEALS, EIGHTH CIRCUIT.




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