abstract
- This work presents a compact testbench that emulates tibiofemoral contact using a sphere-on-sphere knee surrogate. A primary electromagnet applies a constant 50 newton magnetic preload to maintain contact, and a magnetic release mechanism standardizes initial conditions with a synchronized release. A multi-camera system records six-degree-of-freedom motion at 100 hertz with submillimeter accuracy. A single holonomic surface contact point constrains the motion. The sole objective is data acquisition: register trajectories across repeated experiments and report the measured motion. Across trials, contact persisted, transients were repeatable, and trajectories converged to equilibrium. The motion is neither purely translational nor purely rotational; it is a combined trajectory with translation coupled to rotation, consistent with friction-induced tangential slip. Internal forces are not measured; however, the normal reaction and the tangential friction response act throughout the motion and are encoded in the kinematics. The dataset captures signatures of internal contact reactions and provides a basis for subsequent inverse-reconstruction studies under controlled, repeatable conditions.