A 6-DEGREE-OF-FREEDOM TEST SYSTEM FOR THE STUDY OF JOINT MECHANICS AND LIGAMENT FORCES

A joint testing system was designed to transmit a specified motion or force to a joint in all six degrees of freedom (d.o.f.) using a spatia l linkage system for position feedback. The precise reproducibility of position provided by this method of position feedback allows determin ation of in situ ligament forces for external joint loadings. Load on the structure of interest is calculated from sir d.o.f. load cell outp ut after the loaded position is reproduced with all other structures r emoved. In a test of this system, measured lends showed good agreement with applied lends.