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The Scale Model section provides access to basic settings for specifying how a model is scaled.

If the Scale Model box in the upper left-hand corner is not checked, the model will not be scaled.

If the box is checked, the model will be scaled and a number of options become available.

When the box for Preserve mass distribution during scale is checked, the total mass of the generic model is scaled so that it equals the mass of the subject while preserving the relative masses of its body segments. So, for example, if in the generic model the mass of the thigh is twice that of the shank, the mass of the thigh in the scaled model will also be twice that of the scaled shank. If this check box is not checked, the segment masses are scaled based solely on the scale factors applied to each body segment, and the total mass of the model will not equal the experimentally-measured mass of the subject.

Definitions for the measurements used to scale the segments can be inspected and edited by clicking the Edit Measurement Set button . Doing so brings up another table that contains, in each row, the name of a measurement and the list of marker pairs that make up that measurement.

The distances between the experimental marker pairs, relative to the distances between the same markers on the model, are used to compute the scale factors (How Scaling Works). To edit which markers make up a pair, click on one of the markers. A list of available markers will pop up, and you can then select from the list.

Use the  buttons to delete measurements or marker pairs, and the  buttons to add new measurements or marker pairs. Click the  button in the lower right or the  button in the upper right-hand of the window when you are finished inspecting or editing the measurements. Any changes you made will be saved; the only way to undo any changes you made is to undo them manually. Once a measurement has been added to the set, it will appear among the choices you have for computing the scale factors.