[Effects of headers on coagulation parameters]

This paper is testing the hypothesis whether headers can cause micro-traumata which can be verified in lab test.

The study examined micro-traumatic effects of headers for a sample of 22 soccer players by the means of blood tests. In the test arrangement, two probands intensively exchanged headers with a standard football (according to official regulations of the German Football Association) fora period of eight minutes.The average number of ball exchanges per series amounted to around 401 headers for each pair. The effects were measured by selected coagulation parameters.

The results showed significant differences in the concentration of leucocytes and thrombocytes. The variance analysis of coagulation parameters revealed no significant change for fibrinogen concentration, INR and Quick. By contrast, the reduction of aPTT after the headers was significant.

As for an interpretation of these results, the observed increase of the parameters may be characterised as a reaction to stress. The increase of thrombocytes could be seen as response of the corpuscular coagulation system to traumatisation. As aPTT is significantly reduced post intervention, this furthermore reflects an activation of the plasmic coagulation system induced by trauma.