Recently proposed joint interface modes (JIM), which have been presented at the IMAC 25th, do consider Newton's 3rd law across a joint already at the stage of mode generation which leads to significant improvements in the subsequent mode based computation where nonlinear contact forces are applied. In the latter publication the computation of the JIM is based on a general eigenvalue problem of a statically reduced mass and stiffness matrix. This approach has certain drawbacks in terms of interpretability and in terms of an 'a priory' - estimation of the required number of JIM. In this contribution a prober orthogonal decomposition (POD) based method for the computation of the JIM is introduced. In this context the JIM can be interpreted as kind of 'energy modes' so that this procedure holds a meaningful physical interpretation as well as an 'a priory' - estimation of the required number of JIM.