I suspect that a computer model could help if you gave it enough input data fields, but I doubt that such a procedure would be cost-effective for anyone besides top racers. In order for a stick-man approximation to be worthwhile, you would have to define things like "enough bend in the arms", which is going to vary based on a whole lot of biological factors.

Even the very basic data, like bone length and weight distribution, would be difficult to measure precisely without specialized equipment.