102 
where (Z, Y, ) is the kinetic center of the ankle joint, 
(Z UN ) is the kinetic center of the knee joint, 
( Z Y.) is the kinetic center of the hip joint. 
Fig. 9 shows the angle of the knee joint. Using computer 
graphics, the human model is drawn in the sagital plane by 
a 3-D spline curve connecting the body segments based 
on 3-D vectors. Fig. 10 shows the simulation of the sit-to- 
standing sequence of the plegic-side of seriously 
hemiplegic patients. It shows that the flexion and exten- 
Fig. 9 Angle of the Knee Joint sion movements of hip and knee joints are not enough. 
  
  
Fig. 10 Simulation of Sit-to-Standing Sequence ( Plegic-Side of Seriously Hemiplegic Patinent) 
In case of a moderately plegic patient, Fig. 11 shows that the moment of inertia of the normal-side knee is slightly larger 
fluctuation than on the plegic- side. In case of seriously plegic patient, Fig. 12 shows same , but the fluctuations of moment 
of inertia in both sides are larger and not smoother than for the moderately plegic patient. 
2 —— normal-side ---- plegic-side kgm? — normal-side ---- plegic-side 
kgm - 
0.5 , 05 r 
0.4 
0.3 
  
  
   
2 sec 
Fig. 11 Knee Moment of Inertia (moderate) Fig. 12 Knee Moment of Inertia (serious) 
Fig. 13 shows that the fluctuation of knee angle displacement. It is larger in seriously plegic patient Fig.14 shows that 
fluctuation of knee angular velocity. It is larger in seriously plegic patient. 
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop “From Pixels to Sequences’, Zurich, March 22-24 1995