This paper deals with the development and application of a new space curved frame finite element to be used for crash analysis (non-linear). The frame finite element has been developed using a mixed variational principle (complementary form) and using rotations as independent variables. The formulation has been validated for problems of large deflection and rotation, and for problems involving initially curved members. Based on the validation performed, it is expected that crash problems may be modelled using a single element per member thus retaining computational efficiency while performing an accurate analysis. An illustrative example (modelling of an S-leg seat) is presented here to illustrate the benefits of the proposed approach to a designer.