Ordinary diseases of life are not compensable injures based on the rationale that the employer should not be responsible for conditions which are the result of the claimant’s exposure to conditions which affect the general population and do not have their origin in some specific work-related exposure or harm. The defense is based on the statutory definition of occupational disease which can be found at Tex. Lab. Code § 401.011(34)
. The definition of occupational disease necessarily excludes “an ordinary disease of life to which the general public is exposed outside of employment, unless that disease is an incident to a compensable injury or occupational disease.” This exclusion of ordinary disease of life is necessary to prevent a carrier from being liable for all conditions which an employee may contract while employed.
A successful defense of ordinary disease of life will normally focus on the fact that there is a causal link between the activity on the job and the resulting condition and that the condition is inherent in that particular type of employment as compared with employment generally. The employee is normally required to establish the causal link by reasonable medical probability, so a successful defense must likewise almost always be based on medical evidence. Proof of causation must be established to a reasonable medical probability by expert medical evidence where the subject is so complex that the fact-finder lacks the ability from common knowledge to find a causation connection. See Appeals Panel Decision No. 110108. Neck and back problems resulting from repetitive driving, sitting, bending or riding are normally placed in the category of ordinary diseases of life. See Appeals Panel Decision No. 950071. Excessive amounts of walking are typically not compensable unless a specific incidence of injury can be pinpointed. If the risk was one that the employee would have encountered irrespective of her employment, the resulting injury is likely not compensable. Appeals Panel Decision No. 030033.