[data,vecStatic] = jointcentreStiefStatic_data(data,joint,mkr_lat,mkr_med)
computes knee and ankle joint centres based on the medial and lateral
markers (mid-point).
ARGUMENTS
data ... zoo data struct to operate on
joint ... name of joint ('knee' or 'ankle')
mkr_lat ... lateral joint marker (lateral e.g. 'KNE' or 'ANK')
mkr_med ... medial marker (e.g. 'KNM' or 'MMA')
RETURNS
data ... zoo data with joint centre virtual markers appended
('R/LKnee/AnkleJC')
vecStatic ... Vector pointing from mkr_lat to joint centre (expressed in
global coordinate system, displaced to origin). This vector
can be added to the position of the dynamic trial mrk_lat
to obtain the dynamic positions of the joint centre
during movement trials
NOTES:
- Algorithm: Joint centres set as midpoint between 'mkr_lat' and 'mkr_med'.
See Stief et al. "Reliability and Accuracy in Three-Dimensional Gait Analysis:
A Comparison of Two Lower Body Protocols". J App Biomech. 2013.
See also jointcentreStiefDynamic, bmech_kinematics