RSA precision
The condition number (CN), describing the dispersion of the marker model, was mean 298 (SD 346) in the greater/lesser trochanter, mean 126 (SD 16) for the screw, and mean 120 (SD 61) for the head/neck segment. The rigid body error for marker stability was set at 0.35 mm. When accepting CN higher than 150, the verification of precision is essential [