The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
Phase I: 
Preparation 
Phase II: 
Delivery 
Phase III: 
Follow 
through 
Hip and torso 
orientation 
Hip and torso 
orientation 
Elbow 
separation 
Elbow 
separation 
Hand follow- 
through 
Front foot 
step 
Front foot step 
Centre of 
mass transfer 
Rear foot push 
Rear foot 
push 
Trunk flexion 
Trunk flexion 
Table 1. Throw phase and type of measurement required 
Phase I: Preparation 
The preparation phase starts when the player’s hands first start 
moving backwards in the act of throwing the ball, and ends 
when the ball is at its furthermost point behind the player’s 
head, about to change direction towards target (Figure 7a; b). 
This phase consists of: i) hip and torso orientation; ii) elbow 
separation; iii) front foot step; and iv) trunk flexion. These 
movements are described and illustrated below. 
i) . Hip and torso orientation 
The hips and the shoulders should be perpendicular to the 
target or very close to perpendicular at setup and during 
delivery of the throw (Figure 8a). The variable measured is 
the hip and shoulder angle. 
ii) . Elbow separation 
The elbows must stay a constant distance apart in relation 
to the shoulders during the throwing action. The variable 
measured is the elbow width (Figure 8b). 
iii) . Front foot step 
The player must make a step towards the target and this 
will increase with the length of the throw. The variables 
measured are the step length and its direction (Figure 8a; 
b). 
iv) . Trunk flexion 
The player will flex his trunk during throwing, especially 
on longer throws. The variable measured is the absolute 
trunk angle. 
(a) Hip and «mo orientttkm 0>) riho» «separation 
Figure 8. (a). Hip and torso orientation; (b). Elbow separation. 
(a) From fool step position before ihrmv <b) Front foot step position after throw 
Figure 9. Front foot step position before and after throw. 
3. RESULTS AND ANALYSES 
3.1 Spine study 
The system calibration shows that the 3D measurement 
accuracy is 0.8 ± 0.35 mm. Table 3 shows the vector change 
between the morning and the dinner epoch. The positions of 
the anthropometric landmarks used in the study are shown in 
Figure 10. Table 4 shows the angle change in the saggital plane 
between the morning and dinner epoch. 
Part of 
spine 
Change (mm) 
Am-Pm 
SD 
Comments 
Vector Tl- 
PSIS 
10.2 
5.6 
0.6% of height of 
subject 
Vector Tl- 
L1 
6.7 
3.4 
66% of vector Tl- 
PSIS 
Vector Ll- 
PSIS 
3.7 
5.3 
36% of vector T- 
PSIS 
Table 3. Vector change between the morning and the dinner 
epoch measurements. 
Part of spine 
Change 
(degrees) 
Am-Pm 
SD 
Comments 
Thoracic angle 
1.7 
2.2 
Lumbar angle 
-0.4 
4.0 
Thoracolumbar 
angle 
Back 
-1.9 
2.7 
0.8% of 
population 
Thoracolumbar 
angle 
Front 
-0.6 
6.0 
88% of 
population 
Table 4. Angle change in the saggital plane between the 
morning and the dinner epoch 
Figure 10. A graphic plot of the spine anthropometric marks. 
3.2 Limb coordination study 
3.2.1 TAM measurement 
As discussed elsewhere the accuracy of a throw was measured 
by the TAM system. Figure 4 shows the three positions where 
the designated jumper could appear along the middle of the 
two-row of jumpers during a throw, namely: 1) at the front; 2) 
at the middle; and 3) at the back. Throwers were informed of 
the position of the virtual jumper before each throw at the