Reprinted with permission from
The Missouri Trial Attorney,
Volume XX, Number 4, Winter 2002
Copyright 2002, Missouri Association of Trial Attorneys

Scott A. Wilson
The Hines Law Firm, L.L.C., Columbia

Workers’ compensation claims based on an occupational disease or repetitive motion theory of liability are often more difficult than single trauma injuries or “accidents” in that they usually involve multiple employers, multiple insurance companies, and multiple claims. The nature of the medical conditions involved, with true medical causation or the exact point of “disability” often impossible to determine, leads to defenses from successive employers with each attempting to attribute liability to the other for the worker’s occupational disease or injuries.

Missouri’s Workers’ Compensation Law contains a provision that assigns legal liability for a worker’s occupational disease to the employer that last exposed the worker to the hazards of the occupational disease, no matter how short the period of employment.1 This provision, known as the “Last Exposure Rule,” is a rule of convenience intended to provide an easy, predictable means of assessing liability. Unfortunately, ease and predictability have not prevailed in practice as the rule lacks any guidance in determining the point of “last exposure” in cases where the exposure is ongoing and continues with a subsequent employer. The determinative issue in most all repetitive motion injury or occupational disease cases, such as carpal tunnel syndrome claims, is which employer subjected the claimant to the “last exposure” when the worker performed jobs which could cause the disease while working for multiple successive employers.

The Missouri legislature attempted to clarify occupational disease cases in 1993 by further defining what proof is necessary in order for such claims to be compensable and which employer should be held responsible. The legislation enacted in 1993 added Section 287.067.7 which created an exception to the Last Exposure Rule: the Athree-month” exception C what is now commonly referred to as the “90-Day Rule.”2 This exception allows an employer to shift liability back to the previous employer in certain cases if the employee has not worked for the current employer for at least three months.

However, the statute failed to define the point from which the three-month period begins in order to determine which of the successive employers is liable for the injury. The question remained whether the three-month period begins at the “first event” (often the date of medical diagnosis of the condition), the date the claim was filed with the Division of Workers’ Compensation, the date of “disability” (such as the date employee first lost time from work), or at some other point, such as when the claimant became subjectively aware of the work-related condition.

This confusion has since been compounded by conflicting opinions of the Labor and Industrial Relations Commission and the three districts of the Court of Appeals, leaving claimants’ attorneys no choice but to file against every employer and letting the administrative law judge and the various appeals tribunals to eventually determine which employer is liable. It is not uncommon in occupational disease or repetitive trauma cases for claims to be filed against four or five employers, some of which have multiple insurers. A fight then ensues, primarily between the employers and insurers, as to which employers exposed the claimant to the occupational disease and whether each could avoid liability under the 90-Day Rule.

The Supreme Court of Missouri has recently addressed the confusion in Endicott v. Display Technologies, Inc., et al., 77 S.W.3d 612, Mo.banc (2002). In Endicott, the Court adopted a “bright-line” rule affixing the date from which the 90-Day Rule will be applied as the date of claim.3 Although this decision appears to give both the claimants and employers a clear standard in applying the Last Exposure Rule and the three-month exception, it could lead to additional confusion and numerous complex issues remain in occupational disease cases.

Endicott v. Display Technologies, Inc., et al.

Claimant Norman Endicott, Jr. worked for four successive employers between 1981 and 1998. During this time he was diagnosed with three separate occupational diseases to his upper extremities. He was first employed by Display Technologies, Inc. building and testing computer monitors requiring repetitive use of his hands and arms from 1981 to January 1998. He filed and settled his first claim alleging carpal tunnel syndrome for 10% disability of the right wrist in 1994.

From October 1997 to January 1998 his symptoms reappeared while disassembling the plant, working 72-hour weeks. He then took a similar job at ASAP Services, Inc. where he worked from February 10 to March 30, 1998. He continued to have problems with his upper extremities and was diagnosed with right elbow bursitis on March 2, 1998, during his brief employment at ASAP. While unemployed he underwent nerve conduction studies and EMG testing and was diagnosed with moderate to severe carpal tunnel of the left wrist, right neurogenic medial motor changes, right carpal tunnel entrapment and possible lateral epicondylitis on the right side.

Endicott then took a job at ADECCO Employment Services, Inc., an employment/temporary agency, on April 22, 1998 which placed him at Graphic Technologies, Inc. (GTI) performing repetitive job duties. He was then diagnosed with extensor tendonitis of the right elbow and median nerve dysfunction on the right and carpal tunnel release was recommended on the left wrist during the time he was employed by ADECCO. Further complicating the case, he then became a permanent employee of GTI on July 17, 1998 – just under 90 days.

Endicott filed a Claim for Compensation against all four employers on November 2, 1998 alleging a date of onset “on or about December 1997.” His problems continued. At his attorney’s request, he was seen by an orthopedic surgeon on January 25, 1999 who diagnosed bilateral thoracic outlet syndrome and right cubital tunnel syndrome. Endicott then amended his claim in May, 1999, adding occupational diseases or injuries to the right elbow and both shoulders.

Endicott’s doctor testified that his problems were caused by repeated minor trauma to his upper extremities during his various jobs, each of which were capable of producing the problems, and that it was Endicott’s position that most of the problems started at Display Tech and increased at ASAP, but remained steady while working for GTI.

The Administrative Law Judge found GTI liable for all of claimant’s current conditions, finding that, under the Last Exposure Rule, GTI was the last employer to expose Endicott to repetitive activity capable of producing the occupational diseases for over three months prior to the filing of the claim, citing a recent Southern District case and language of an older Missouri Supreme Court case.4

The Labor and Industrial Relations Commission reversed the ALJ relying on the date of diagnosis of each particular occupational disease to affix liability, citing two Eastern District Court of Appeals holdings.5 The Commission held Endicott’s first employer, Display Technologies, liable for his bilateral carpal tunnel syndrome and bursitis of the right elbow, and his last employer, GTI, responsible for the bilateral thoracic outlet syndrome based on when each was diagnosed. The Southern District Court of Appeals affirmed the Commission and the Supreme Court accepted transfer, together with another case with similar facts, presumably to finally address the numerous conflicting opinions in the Court of Appeals.6

The Supreme Court of Missouri reversed and remanded the case flatly stating that the date of claim is the relevant date under the Last Exposure Rule and the three-month exception. Judge Benton wrote the rather concise opinion for the court finding:

The last exposure rule is not a rule of causation. Johnson, 911 S.W.2d at 288. Rather, as a starting point, the last employer before the date of claim is liable if that employer exposed the employee to the hazard of the occupational disease. Id.; Maxon v. Legget & Platt, 9 S.W.3d 725, 730 (Mo. App. 2000).7

The Court determined that the three-month exception of Section 287.067.7 does not assess liability based on the date of diagnosis of each occupational disease, as GTI asserted. Because GTI was last in the line of Endicott’s employers to expose him to repetitive motion prior to the date the claim was filed and his exposure was for more than three months, the court held GTI liable for each of Endicott’s three separate occupational diseases, even though two of the three conditions had been diagnosed prior to him becoming an employee of GTI.8

Apparently hoping to wash its hands of the issue by adopting the “date of claim” rule, the court specifically overruled all prior cases holding otherwise.9 In doing so, the court expanded on the “rule of convenience” nature of the Last Exposure Rule by choosing the easily-determined, fixed “date of claim” rather than the more causally relevant but difficult to ascertain date of medical diagnosis. The Court cited the sentence structure of the language of ‘287.067.7 in an attempt to show why the phrase “exposure to the repetitive motion which is found to be the cause of the injury” should not be interpreted to fix liability at the time the disease is diagnosed.10 Yet the Court failed to explain the absence of any reference to “claim” in the three-month exception of 287.067.7, unlike the language of 287.063.2, or to show any particular relevance or legal significance associated with the date the claim was filed with the Division of Workers’ Compensation.11

At least ending on a positive note, the Court in Endicott also held that the notice requirement in 287.420 does not apply to occupational disease claims, finally putting to rest another tired defense which had been raised in nearly all such cases.12

Application of the 90-Day Rule after Endicott

For better or worse, it is now clear that under the Last Exposure Rule when the claimant has been exposed to the hazards of an occupational disease by multiple employers, the starting point is the date the Claim for Compensation is filed. The court in Endicott states that the Last Exposure Rule Ais not a rule of causation.”13 By propounding the “date of claim rule,” the court has adopted a bright-line test affixing legal causation, regardless of proof of medical causation or all evidence regarding the claimant’s development of the disease. So long as the medical evidence in the record reflects that a claimant suffering from an occupational disease performed job activities which could cause the disease at the time the claim is filed, liability is first assigned to the last employer regardless of any and all circumstances and events occurring prior to the filing of the claim.

The burden of proof then shifts to the last employer to show, under the 90-Day Rule, that both: (1) The employee has not been exposed to the hazards of the occupational disease for three months while working for that employer, and (2) that the repetitive motion with a prior employer was Athe substantial contributing factor” in causing the medical condition.14

The last employer at the time the claim is filed must prove it meets both prongs of the defense: the 90-day provision and the causation-type test. The first prong is met if the worker had not been employed for at least 90 days at the time the claim was filed, or if the employee worked there for over three months but did not perform repetitive motion tasks over a period of at least 90 days. A more tenuous defense could be raised claiming the employer did not perform repetitive motion activities for 90 consecutive days. However, at least one district of the Court of Appeals has held that the exposure to the repetitive motion need not occur on a daily basis, so long as the exposure existed throughout a three-month period.15

If B and only if B the first prong of the 90-Day Rule exception is met, that employer must also show that the repetitive motion at a prior job was Athe substantial contributing factor” in causing the occupational disease. This language is, of course, different from the usual Aa substantial factor” standard found in the statutory definition of Ainjury.”16 Though this language does not appear to refer to any particular standard, the Eastern District has held it to mean Aa factor which is the more responsible of the two contributing factors,” and that this is satisfied if expert testimony reflects that the prior employment was more substantial in duration or more significant in causing the disease, or both.17 Endicott did not give any further guidance regarding this standard since the last employer could not make it past the first prong of the 90-day exception.

It should be noted that the three-month exception to the Last Exposure Rule applies only to employers and not to insurers.18 In Smith v. Tiger Coaches, Inc., 73 S.W.3d 756 (Mo. App. E.D. 2002), the Eastern District recently held that the 90-Day Rule does not allow an insurer to shift liability to the prior insurer in an occupational disease claim.19 Taken with the holding in Endicott, the insurer providing coverage on the date the claim is filed is the liable insurer, no matter how brief the period of coverage.

Also, Endicott does not appear to affect the actual date of injury used in determining the wage rate under 287.250, since the three-month exception does not refer to a date of injury.20 Although it could be argued that the date of injury is now the date the claim was filed, Endicott does not specifically address this issue. Claimant’s counsel is free to use the date of injury used in the Report of Injury, the date the claimant first missed time, the date of diagnosis, or to stipulate to another date for use in computing the rate of compensation. However, the courts may see the benefit of another bright line rule to affix this date as prior case law has been contradictory on this issue, as well, varying between the date of last exposure and the date of “disability” C meaning lost time or other “compensable disability.”21

90-Days to File Claim Against Prior Employer

Effectively, then, Endicott imposes a practical 90-day type of statute of limitations for filing an occupational disease claim against a previous employer once the employee has left the prior employment and begins another job where exposed to the hazards of the occupational disease. In order to pursue a claim against the prior employer for an occupational disease and to allow the subsequent employer a 90-Day Rule defense, the claim must be filed with the Division of Workers’ Compensation within 90 days after beginning new employment, though the usual, true statute of limitations would still apply to the claim itself against each employer.

This filing deadline becomes particularly important in cases where the employee has taken a new job and wants to avoid any potential negative repercussions associated with filing a claim against the new employer after having only worked for the new employer a relatively short period of time, an unfortunately common scenario. The date of claim rule adopted in Endicott will affect the strategies of those practicioners who prefer to wait to formally file a Claim for Compensation (Form 21) until there are benefits due and owing which have been improperly denied by the employer/insurer. The rule ignores the fact that, most likely, a majority of all claims filed, both pro se and by counsel, are not actually filed with the Division of Workers’ Compensation until long after the claimant has been diagnosed with an occupational disease and has undergone medical treatment, lost work, and has been released from further treatment, has been fired, or both.

Finally, the date of claim rule, in essence, encourages employers to fire employees who show signs of developing an occupational disease so as not to be held liable by the time a claim is filed, particularly considering the lack of legal protections afforded Missouri’s workers. Additionally, the rule discourages other employers from hiring workers who have been diagnosed with B or have the symptoms of B an occupational disease, and further discourages employees from postponing surgery in order to try alternative conservative treatment for fear of being fired and having the surgery denied.22

Caution is Advised with the Filing of Claims

If claimants are aware of the date of claim rule, they are now able to fix the determinative date under the last exposure rule by choosing when to file a claim and which employers to file against. Assuming the medical evidence supports the claim, claimants can now plead on the claim form the specific dates of the exposure to hazards of the occupational disease and file the claim on a particular date in order to limit or preserve defenses based on the 90-Day Rule. It should be cautioned that in cases where there is potentially an issue of medical causation with regard to a particular employment, there may be no choice but to file against all potentially liable employers. Claimants’ attorneys must not risk an injured worker’s right to recover for an occupational disease by being overly artful or too narrow in the filing of claims for ease of handling or simplicity’s sake.

Unfortunately, by assigning liability for the claimant’s occupational diseases to the employer at the date the claim was filed, Endicott allows prior employers to escape liability for any prior similar occupational diseases, medical conditions, or symptoms related to the same part of the body alleged in the claim. This would presumably be true even in cases where the worker had already had surgery to correct the occupational disease and the surgery had been authorized by the original employer/insurer.

Obviously, this could lead to the incongruous result of a subsequent employer being held liable not just for permanent partial disability from the injury itself, but also for claimant’s initial medical treatment, surgery, and missed work C and resulting medical bills and temporary total disability benefits C incurred prior to the claimant ever having worked for that employer. In this sense, the rule of convenience may not seem so convenient to subsequent employers which will likely be made to indemnify prior employers/insurers for the benefits previously paid on the claim.

Claimants’ attorneys must also be certain that the medical testimony in the record supports the finding of liability against the employer pled in the claim. Though medical testimony is not required as to which employer most exposed the claimant to the hazards of the occupational disease, it is potentially fatal to the claim if the medical evidence does not both describe the job activities performed by the claimant for each of the employers in question and find that they were sufficient to cause the occupational disease or medical condition.23 Because there is often conflicting medical evidence in the record, it is still strongly advised to err on the side of filing against all employers for which the claimant performed any repetitive motion jobs.

Finally, claimants’ attorneys should also err on the side of pleading an occupational disease in the original claim rather than waiting and attempting to amend a claim which alleged only an accident or single-trauma injury. Numerous cases have rejected attempts to add an occupational disease theory of liability by amending an original claim which pled only a specific accident.24 Similarly, an amended claim that adds an additional body part has been held to not relate back to the original claim but was considered a new and distinct claim.25 It is a safer practice to either include both theories in the original claim or to file two separate claims as early as possible: one alleging the specific accident and the other alleging the exposure to and development of an occupational disease so as not to give rise to a statute of limitations defense.


Prior case law in occupational disease cases was clouded, at best, in determining the relevant date which affixes liability under the Last Exposure Rule and the three-month exception of the 90-Day Rule. Endicott, for better or worse, should at least clear up the prior confusion as to the proper date in determining the employer liable under the Last Exposure Rule. Occupational disease claims remain complex, however, and particular attention must be paid as to the date the claim is filed and to which employers are included in the claim B as well as to the medical evidence in the record B to be sure the claimant obtains all benefits available under current law.

1. Section 287.063, RSMo. (1994) states, in pertinent part:
(1) An employee shall be conclusively deemed to have been exposed to the hazards of an occupational disease when for any length of time, however short, he is employed in an occupation or process in which the hazard of the disease exists, subject to the provisions relating to occupational disease due to repetitive motion, as is set forth in subsection 7 of section 287.067, RSMo. (b) The employer liable for the compensation in this section provided shall be the employer in whose employment the employee was last exposed to the hazard of the occupational disease for which claim is made regardless of the length of time of such last exposure.
(2) Section 287.067.7, RSMo. (1994) states: With regard to an occupational disease due to repetitive motion, if the exposure to the repetitive motion is for a period of less than three months and the evidence demonstrates that the exposure to the repetitive motion with a prior employer was the substantial contributing factor to the injury, the prior employer shall be liable for such occupational disease.
3. Endicott v. Display Tech. Inc., et. al, 77 S.W.3d 612 at 615.
4. Maxon v. Legget & Platt, 9 S.W.3d 725 (Mo. App. S.D. 2000); Johnson v. Denton Constr. Co., 911 S.W.2d 286 (Mo. banc 1995.
5. Arbeiter v. National Supermarkets, Inc., 990 S.W.2d 142 (Mo. App. 1999); Cuba v. Jon Thomas Salons, Inc. 33 S.W.3d 542 (Mo. App. 2000).
6. Oswald v. National Fabco Mfg. Inc., 77 S.W.3d 611 (Mo. banc 2002) was handed down the same day as Endicott.
7. Endicott v. Display Tech. Inc., et. al, 77 S.W.3d 612 at 615.
8. Id. at 616.
9. Cuba v. Jan Thomas Salons, Inc., 33 S.W.3d 542 at 546 (Mo. App. 2000); Arbeiter v. National Super Markets, Inc., 990 S.W.2d 142 at 145-46 (Mo. App. 1999).
10. Endicott v. Display Tech. Inc., et. al, 77 S.W.3d 612 at 615.
11. Arbeiter v. National Supermarkets, Inc., 990 S.W.2d 142 (Mo. App. 1999).
12. Endicott v. Display Tech. Inc., et. al, 77 S.W.3d 612 at 616.
13. Id. at 615.
14. Id.
15. Maxon v. Legget & Platt, 9 S.W.3d 725, 732-733 (Mo. App. S.D. 2000).
16. Section 287.020.3(2)(a) RSMo. 2000.
17. Mayfield v. Brown Shoe Co., 941 S.W.2d 31 at 36 (Mo. App. S.D. 1997).
18. Tunstill v. Eagle Sheet Metal Works, 870 S.W.2d 264 (Mo. App. S.D. 1994); Crabill v. Hannico; 963 S.W.2d 440 (Mo. App. 1998); Feltrop v. Eskens Drywall and Insulation, 957 S.W.2d 408 (Mo. App. 1997).
19. Smith v. Tiger Coaches, Inc., 73 S.W.3d 756 (Mo. App. E.D. 2002).
20. Bull v. Excel Corp., 985 S.W.2d 411 (Mo. App. W.D. 1999).
21. See, Renfro v. Pittsburgh Plate Glass Co., 130 S.W.2d 165 (Mo. App. E.D. 1939); Enyard v. Scullin Steel, 390 S.W.2d 417 (Mo. App. E.D. 1965); and Gillam v. General Motors Corp., 913 S.W.2d 81 (Mo. App. E.D. 1995).
22. See, Cuba v. Jan Thomas Salons, Inc., 33 S.W.3d 542 at 546 (Mo. App. 2000); aside from any potential violations of the Americans with Disability Act.
23. Brundige v. Boehringer Ingelheim, 812 S.W.2d 200 (Mo. App. 1991); Putnam-Heisler v. Columbia Foods, 989 S.W.2d 257 at 260-261 (Mo. App. 1999).
24. Bissell v. Paramount Cap Manufacturing Co., 962 S.W.2d 13 (Mo. App. S.D. 1998); Holaus v. William Zickell Co., 958 S.W.2d 72 (Mo. App. E.D. 1997).
25. Colony v. Accurate Superior Scale Co., 952 S.W.2d 755 (Mo. App. W.D. 1997); Hunsicker v. J. D. Industries, 952 S.W.2d 376 (Mo. App. W.D. 1997).