In all claims for compensation for hernia resulting from injury arising out of and in the course of the employment, it must be definitely proved to the satisfaction of the division or the commission:
§ 287.195, RSMo
RSMo 1939 § 3705, A.L. 1947 V. II p. 438, A.L. 1951 p. 620, A.L. 1953 p. 530, A.L. 1955 p. 588, A.L. 1957 p. 560 § 287.191, A.L. 1965 p. 397, A.L. 1980 H.B. 1396