Biomedical Engineering Reference
In-Depth Information
Tabl e 2
Bony landmarks used on the definition of the local coordinated system of the thorax,
scapula and humerus, according with Wu et al. [
50
]
Yt
Yt: The line connecting the midpoint between PX and
T8 and the midpoint between IJ and C7 pointing
upward
Zt: The line perpendicular to the plane formed by IJ, C7
and the midpoint between PX and T8 pointing to the
right
Xt: The common line perpendicular to Zt and Yt-axis
pointing forward
Ot: The origin coincident with IJ
Xt
Zt
Ys: The common line perpendicular to Xs and Zs-axis
pointing upward
Zs: The line connecting TS and AA pointing to AA
Xs: The line perpendicular to the plane formed by AI,
AA and TS, pointing forward. Note that because of
the use of AA instead of AC, this plane is not the
same as the usual plane of the scapula bone
Os: The origin coincident with AA
Ys
Xs
Zs
Yh
Yh: The line connecting thigh and the midpoint of EL
and EM, pointing to GH
Zh: The common line perpendicular to the Yh and
Zh-axis pointing to the right
Xh: The line perpendicular to the plane formed by EL,
EM and GH pointing forward
Oh: The origin coincident with GH
Zh
Xh
6,5 cm) was used on
bony landmarks digitalization in order to link sensors position to the local anatom-
ical coordinate systems (LCS) (Table
2
) and subsequently calculated segments and
joint rotations by combining the LCSs with the sensor motions. Segments LCSs
and joint rotations definition, expressed in Euler angles, were made according to the
shoulder ISB standardization protocol [
50
].
A fourth sensor mounted on a hand-held acrylic stylus (
˙
