Additionally, a duty rests on a party-plaintiff to make a submissible case by substantial evidence of probative force and to remove the case from the realm of speculation, conjecture and surmise. Zeigenbein v. Thornsberry, 401 S.W.2d 389, 393 (Mo.1966); Probst v. Seyer, 353 S.W.2d 798, 802 (Mo.1962); and Rossmann v. G.F.E. Corporation of Missouri, 596 S.W.2d 469, 472 (Mo.App.1980). Substantial evidence is that which, if true, has probative force upon the issues, and from which the trier of facts can reasonably decide a case. Zeigenbein v. Thornsberry, supra, 401 S.W.2d at 393. Concomitantly, where evidence equally supporting two inconsistent and contradictory factual inferences as to ultimate and determinative facts is solely relied on to make a submissible case, there is a failure of proof as the case has not been removed from the tenuous status of speculation, conjecture and surmise. Lappin v. Prebe, 345 Mo. 68, 131 S.W.2d 511, 513 (1939); and Osterhaus v. Gladstone Hotel Corporation, 344 S.W.2d 91, 94 (Mo.App.1961). Determination of whether the evidence in a given case is substantial, as well as whether inferences drawn from a given state of facts are reasonable, are questions of law to be judicially resolved. Hoock v. S.S. Kresge Co., 361 Mo. 139, 230 S.W.2d 758, 760 (banc 1950); and Tharp v. Monsees, 327 S.W.2d 889, 899 (Mo. banc 1954).
Before reviewing the evidence in conformity with the obtaining principles for determining submissibility on appellate review, and taking into consideration all attendant ramifications, it is appropriate to reiterate appellant’s theories of negligence regarding the respective respondents. Appellant’s theory of negligence against respondent hospital was that its nursing staff did not comply with the admitting physician’s written order to turn appellant every two hours. Appellant’s theory of negligence against respondent doctors was that they failed to check the patient’s hospital records for compliance by respondent hospital’s nursing staff with the admitting physician’s written order to turn appellant every two hours. If appellant failed to prove by substantial evidence of probative force that respondent hospital’s nursing staff did not comply with the admitting physician’s order to turn appellant every two hours, then she failed to make a sub-missible case against respondent hospital. Concordantly, if appellant failed to make a submissible case against respondent hospital she also failed to make a submissible case against respondent doctors as her theory of negligence against them, in a final sense, is inextricably bound to the alleged failure of respondent hospital’s nursing staff to turn appellant every two hours in compliance with the admitting physician’s order.
An appropriate review of the evidence is now in order. On June 23, 1979, appellant was admitted to respondent hospital for treatment of a spiral fracture to her right femur. Her admitting physician, a specialist in internal medicine, is one of the respondent doctors. An orthopedic surgeon who treated the spiral fracture, is also one of the respondent doctors. The remaining respondent doctors were associates of either the admitting physician or the orthopedic surgeon just mentioned and purportedly participated in appellant’s care and treatment at respondent hospital on intermittent occasions.
Appellant, at the time of her admission to respondent hospital, was beset with a number of medical complications which made her highly susceptible to decubitus ulcers — paraplegia resulting from an accident which occurred some twenty years ago, emphysema, poor circulation, osteoporosis, anemia, vulnerability to thrombosis, and a recent fracture of her right hip which had been surgically corrected. Therefore, upon admission her admitting physician entered a written order in her hospital records that she be turned every two hours.
Between June 23, 1979, and the morning of July 3, 1979, while a patient in respon