The oar plays an important role in the rowing system by
transmitting the force developed by the rower to the blade.
Joint moments generated by the rower result in movement of
the rower with respect to the shell. This causes a corresponding
movement of the oar handle that is resisted by the interaction
of the blade and the water. The motion of the oar is
partially constrained by the oarlock, restraining the oar from
sliding axially. For this analysis, a single oar is modelled, yet is
representative of either a scull or sweep oar. Figures 2 and 3
are free body diagrams, and derivations for the equations of
motion are provided below. (Note that the forces in figures 2
and 3 are not constrained to the vector directions shown).