The article refers to experimentally gathered values which are necessary for computation of human body tolerance level for external load. Content of this article is submitted as an original research. The article presents resultant values of acceleration, impact duration and forces acting during a blow to the head of a dummy. Computation of human body tolerance level is dependent on the overall acceleration of head after the impact, applied force and stress. We obtained correlation between impact velocity of the impactor and duration of this impact. Further we elicited relation of the resultant head injury to the neck stiffness and also restraining factors (i.e. gloves and caps). Last but not least we aimed at the correlation between HIC15 and injury severity for described sorts of blows. Both bibliography reviews and experiments show significant factors for computations of the tolerance level resulting from external forces. As the most important factors are counted not only head acceleration within a loading phase both also detecting magnitude of applied force and stress per unit area. Course of the head acceleration and applied force are two most significant factors for prediction of the extreme dynamic loading of a human body.