A data processing method for determining six parameters of a contact position of a joint which connects two bones, comprising the steps of acquiring a plurality of sample contact position datasets, each dataset comprising six parameters, acquiring a subset of n of the parameters of the contact position as an input parameter dataset, selecting at least two of the sample contact position datasets based on the input parameter dataset and determining the m=6−n remaining parameters of the contact position based on the at least two selected sample contact position datasets.
