DIRECTIONS:

1. Project film image onto the digitizer surface. Scotch tape your graph paper onto the filmed image.

2. Make an outline drawing of the body. Include some detail.

3. Place point markers on the following locations:
a. end of the toes
b. centers of the ankles
c. center of the knees
d. center of the hip
e. center of the wrist
f. center of the elbow
g. center of the shoulder
h. ends of the fingers
i. seventh cervical vertebra, and
j. top of the head

Where these points are obscured by other body parts or clothing, an estimate of their location must be made.

4. Make a stick figure drawing by connecting the point marks with a straight edge.

5. Place the appropriate triangle of the Walton Template over one end of the body segment lines so that the proximal end of one of the triangle lines coincides with the proximal end of the body segment line, and the distal end of the same triangle coincides with the distal end of the body segment.

6. The center of the mass for each segment is marked on the tracing by drawing a short line through the slot in the triangle. This process is repeated for the remaining segments, selecting the appropriate triangle each time.

7. X and Y axes are drawn on the graph paper in any convenient location.

8. X and Y coordinates for each of the 14 segments are determined and recorded on the diagram of the figure at the respective mass centers and also on the work sheet .

9. Determine the moments of the body segments about the X and Y axes by multiplying the segment mass center values times the proportion of body weight.

10. The algebraic sum of the x products (moment) represents the X coordinate of the total body’s mass center, and the algebraic sum of the Y products (moments) is the Y coordinate.

11. The center of mass is then marked on the graph paper.

WORKSHEET

Sources:

Adrian, M & Cooper, J. (1989). Biomechanics of Human Movement. Indianapolis,: Benchmark Press, Inc.

Hall, S. (1991). Basic Biomechanics. St. Louis: Mosby Publishing Co.

Walton, J. (1970). A template for locating segmental centers of gravity. Research Quarterly. 41:617.