@article{EhrigHeller2019, author = {Rainald Ehrig and Markus O. Heller}, title = {On intrinsic equivalences of the finite helical axis, the instantaneous helical axis, and the SARA approach. A mathematical perspective.}, journal = {Journal of Biomechanics}, volume = {84}, pages = {4 -- 10}, doi = {10.1016/j.jbiomech.2018.12.034}, year = {2019}, }