An injury sustained at the workplace is not compensable where there is no causal connection between the work activity and the injury other than the fact that the injury occurred at the workplace.  Mitchell Miller, Appellant v Missouri Highway and Transportation Commission, Respondent, No. 89960 (Mo. banc, June 30, 2009), Stith, J.

On September 29, 2005, the claimant was working with his MHTC crew repairing a section of road on Route N in Pike County.  He was walking briskly toward the truck containing repair material when he felt a pop and his knee began to hurt.  He frankly admits that his work did not require him to walk in an unusually brisk way; that he normally walks briskly at home and did nothing different than usual when walking at work that day; that nothing about the road surface, his work clothes or the job caused any slip, strain or unusual movement; and that he did not fall or otherwise sustain any additional injuries due to the popping.  He just felt a pop.  A subsequent MRI suggested a tear of the inferior aspect of the meniscus; later surgery instead found and repaired an impinging medial shelf plica.

The ALJ, commission and court of appeals denied the claim as constituting a compensable one after the statutory changes in 2005.  The Supreme Court accepted transfer of the case and affirmed the denial of liability.

"The meaning of these provisions is unambiguous.  An injury will not be deemed to arise out of employment if it merely happened to occur while working but work was not a prevailing factor and the risk involved - here, walking - is one to which the worker would have been exposed equally in normal non-employment life.  The injury here did not occur because Mr. Miller fell due to some condition of his employment.  He does not allege that his injuries were worsened due to some condition of his employment or due to being in an unsafe location due to his employment.  He was walking on an even road surface when his knee happened to pop.  Nothing about work caused it to do so.  The injury arose during the course of employment, but did not arise out of employment.  Under Sections 287.020.2, .3 and .10 as currently in force, that is insufficient .. Accordingly, the injury is not compensable, as there is no causal connection of the work activity to the injury other than the fact of its occurrence while at work." (emphasis added)