Biomedical Engineering Reference
In-Depth Information
2.7
A very simple segmented model of a sitting person is shown in the
schematic visualization in the figure. At the right hand H a force
F
H
and a
moment
M
H
are given by:
F
H
=
5
e
x
+
e
z
M
H
=
e
y
+
3
e
z
,
related to the Cartesian vector basis
. In addition the positions of
the hand H and shoulder S with respect to the origin at the lower end of the
spine are given:
{
e
x
,
e
y
,
e
z
}
x
H
=
4
e
x
−
2
e
y
+
5
e
z
x
S
=
e
x
−
2
e
y
+
4
e
z
.
M
H
F
H
H
S
O
e
z
e
y
e
x
(a) Calculate the moment at the shoulder (point S) as a result of the load
at the hand H.
(b) Calculate the moment at the lower end of the spine O as a result of
the load at the hand H.
