Employee claims that he developed bilateral rotator cuff disease as a result of
of loading cases of beer onto railroad cars. ${ }^{[1]}$
An employee's claim for compensation due to an occupational disease is to be determined under Section 287.067 Mo. Rev. Stat. (2000). It defines occupational disease as:
an identifiable disease arising with or without human fault out of and in the course of the employment. Ordinary diseases of life to which the general public is exposed outside of the employment shall not be compensable, except where the diseases follow as an incident of an occupational disease as defined in this section. The disease need not to have been foreseen or expected but after its contraction it must appear to have had its origin in a risk connected with the employment and to have flowed from that source as a rational consequence. (1993 additions underlined)
Section 287.067.2, which was added in 1993, provides that an occupational disease is compensable "if it is clearly work related and meets the requirements of an injury which is compensable as provided in subsections 2 and 3 of section 287.020. An occupational disease is not compensable merely because work was a triggering or precipitating factor." Subsection 2 of section 287.020 provides that an injury is clearly work related "if work was a substantial factor in the cause of the resulting medical condition or disability." ${ }^{[2]}$
Subsection 3(1) of section 287.020 provides that an injury must arise out of and in the course of the employment and be incidental to and not independent of the employment relationship and that "ordinary, gradual deterioration or progressive degeneration of the body caused by aging" is not compensable unless it "follows as an incident of employment."
Subsection 3(2) of section 287.020 provides that an injury arises out of and in the course of the employment "only if (a) It is reasonably apparent, upon consideration of all the circumstances, that the employment is a substantial factor in causing the injury; and (b) It can be seen to have followed as a natural incident of the work; and (c) It can be fairly traced to the employment as a proximate cause; and (d) It does not come from a hazard or risk unrelated to the employment to which workers would have been equally exposed outside of and unrelated to the employment in normal nonemployment life[.]"
Much of new subsection 3(2) of section 287.020 was contained in the prior definition of an occupational disease set forth in Section 287.067. Section 287.020.3(2)(b), (c), and (d) were part of the former occupational disease statute. Section 287.020.3(2)(a) is a revision of the prior requirement of a direct causal connection between the conditions under which the work was performed and the occupational disease. Direct causal connection is now defined as "a substantial factor in causing the injury." The Supreme Court held in Kasl v. Bristol Care, Inc., 984 S.W.2d 501 (Mo. 1999) that the foregoing language overruled the holdings in Wynn v. Navajo Freight Lines, Inc., 654 S.W.2d 87 (Mo. 1983), Bone v. Daniel Hamm Drayage Company, 449 S.W.2d 169 (Mo. 1970), and many other cases which had allowed an injury to be compensable so long as it was "triggered or precipitated" by work. A substantial factor does not have to be the primary or most significant causative factor. Bloss v. Plastic Enterprises, 32 S.W.3d 666, 671 (Mo. App. 2000); Cahall v. Cahall, 963 S.W.2d 368, 372 (Mo. App. 1998). The additional language in section 287.020.3(1) concerning deterioration or degeneration of the body due to aging probably does not overturn any prior court decisions.
Since the 1993 amendments pertaining to occupational diseases have largely readopted the prior statute, caselaw interpreting the prior statute is of some significance. In repetitive motion cases, ${ }^{[3]}$ as practically all movements of the human body done during the course of employment are also replicated in nonworking environments and as most occupationally induced diseases also sometimes occur in the public at large, the courts have focused on a particular risk or hazard to which an employee's exposure is greater or different than the public at large. Collins v. Neevel Luggage Manufacturing Co., 481 S.W.2d 548, 552-54 (Mo. App. 1972); Prater v. Thorngate, Ltd., 761 S.W.2d 226, 230 (Mo. App. 1988); Hayes v. Hudson Foods, Inc., 818 S.W.2d 296, 299-300 (Mo. App. 1991). Claimant must present substantial and competent evidence that he or she has contracted an occupationally induced disease rather than an ordinary disease of life. The Courts have stated that the determinative inquiry involves two considerations: "(1) whether there was an exposure to the disease which was greater than or different from that which affects the public generally, and (2) whether there was a recognizable link between the disease and some distinctive feature of the employee's job which is common to all jobs of that sort". Id. at 300; Dawson v. Associated Elec., 885 S.W.2d 712, 716 (Mo. App. 1994); Prater at 230; Jackson v. Risby Pallet and Lumber Co., 736 S.W.2d 575, 578 (Mo. App. 1987); Polavarapu v. General Motors Corp., 897 S.W.2d 63, 65 (Mo. App. 1995); Sellers v. Trans World
Airlines, Inc., 752 S.W.2d 413, 415 (Mo. App. 1988).
Claimant must also establish, generally through expert testimony, the probability that the claimed occupational disease was caused by conditions in the work place. Dawson at 716; Selby v. Trans World Airlines, Inc., 831 S.W.2d 221, 223 (Mo. App. 1992); Brundige v. Boehringer, 812 S.W.2d 200, 202 (Mo. App. 1991). Claimant must prove that work was "a substantial factor" in causing "the resulting medical condition or disability." Section 287.020.2. Moreover, "an occupational disease is not compensable merely because work was a triggering or precipitating factor." Section 287.067.2 Mo. Rev. Stat. (2000). The Supreme Court held in Ka